ALBERT

Description: This dataset reports measurements from a laboratory incubation of soils sourced from a boreal peatland and surrounding habitats (Siikaneva Bog, Finland). In August 2021, soil cores were collected from three habitat zones: a well-drained upland forest, an intermediate margin ecotone, and a Sphagnum moss bog. The cores from each habitat were taken from surface to approximately 50cm below surface using an Eijelkamp peat corer and subdivided by soil horizon. The samples were then incubated anaerobically for 140 days in three temperature treatment groups (0, 4, 20°C). Subsamples of the incubations headspace (250 µL) were measured on a gas chromatograph (7890A, Agilent Technologies, USA) with flame ionization detection (FID) for CO2 and CH4 concentrations. The rate of respiration from the samples were calculated per gram carbon and per gram soil as described in the method of Robertson., et al. (1999) and reported here, along with other relevant parameters.

Description: With the ongoing deployment of Global Navigation Satellite Systems (GNSS) ground stations and the modernization of satellite signal systems, the utilization of various augmentation technologies enables the realization of Precise Point Positioning (PPP) in real-time. Augmentation technology, which introduces precise atmospheric and signal-related delays, has become an essential component of high-precision real-time services and is attracting growing interest in scientific research, disaster monitoring, autopilot, etc. Previous studies have dedicated significant efforts to enhance the generation and dissemination of augmentation information on the service side and improve real-time positioning algorithms on the user side. The real-time atmosphere augmentation information with sufficient accuracy and proper constraint, and reliable Ambiguity Resolution (AR) for this purpose is the main focus of current GNSS research. However, these efforts have primarily been concentrated on small or medium-sized regions with the capability for transmitting massive data volumes. Alternatively, they have focused on larger areas, but with slow convergence due to the imprecise nature of atmosphere information. To address the challenge posed by the trade-offs among service area size, correction volume, and the precision of represented correction, a new augmentation strategy is proposed. This approach integrates the advantages of atmospheric delay fitting models, unmodeled residuals, and uncertainty information to achieve rapid and high-precision positioning, all while reducing data transmission volume for larger areas. It also allows users to implement different positioning modes depending on their communication capacity. Additionally, all deviations among different types of receivers and satellite signals are calibrated in this study for reliable AR can be achieved on all reference stations. The main contribution of this thesis is summarized as follows. With the real-time precise orbit, clock, and Uncalibrated Phase Delay (UPD) products, precise atmospheric delay corrections relying on reliable AR can be derived for large-areas augmentation services. To address the challenge of achieving reliable AR across different receiver types and various satellite signals, this thesis proposes a comprehensive method for calibrating receiver-type-related satellite-specific deviations and analyzes the impact of satellite signal bias corrections in data processing. The primary objective is to enhance the reliability of AR, enabling the utilization of all available signals and receiver types in large-area services. Subsequently, new tropospheric and ionospheric delay fitting models applied for large-area are carried out according to the properties of their propagation paths. In addition, the corresponding atmospheric delay uncertainty for large areas is introduced based on the fitting residuals. Finally, a hierarchical mode is developed for augmentation services, leveraging the advantages of the fitting model and uncertainty grid to reduce data volume and incorporating regional fitting residuals using the interpolation model and ionospheric delay error function, depending on the network capability. Based on hierarchical augmentation, positioning in large areas can not only achieve rapid/instantaneous high-precision convergence but also overcome the conflict among correction volume, represented precision, and coverage size. In order to derive precise atmospheric delay and accelerate positioning, implementing reliable and robust AR across all types of receivers and satellite signals is essential. It also demonstrates and discusses the advantages of calibrating satellite-signal and receiver-type-related satellite-specific deviations in AR solutions. The deviations related to receivers in terms of UPD products are assessed and calibrated, confirming that a 0.03 cycle consistency in wide lane UPD can be achieved. The effectiveness of the proposed approach is demonstrated using GPS satellite signals, which can improve the AR rate by at least 10% and produce more reliable results. In addition, the impact of different signal settings and corrections on orbit, clock, and UPD generation, as well as positioning and pseudo-range signal systematic and stochastic residuals, is analyzed. These processing strategies provide flexible observation selections, allowing the utilization of all available satellite signals and receiver types, thereby enabling reliable AR and a higher fixing rate. As a result, an AR fixing rate exceeding 95% is achievable across all stations in large-area services. For precise atmospheric delay modeling over large areas, new models are proposed, including a tropospheric Zenith Wet Delay (ZWD) model and a satellite-wise ionospheric slant delay fitting model. The tropospheric delay model takes the exponential function of water vapor vertical changes into consideration, addressing model anomalies in areas with large altitude differences. The new ionospheric delay fitting model introduces the trigonometric functions to describe differences in slant path delays between the optimal reference propagation path and others, achieving superior modeling performance in large areas. The precision of the fitting model, utilizing a 200 km station-spacing network, demonstrates tropospheric ZWD and ionospheric slant delays of 1.3 cm and 8.9 cm, respectively, with smaller standard deviations. These new fitting models overcome the challenge of handling massive information for providing station-wise corrections and avoid an increase in the number of coefficients. In addition to the function model, the stochastic model, i.e., uncertainty information, is essential for describing the quality of corrections. The atmospheric delay uncertainty for the large-area fitting model is generated based on the fitting residuals and represented in forms of grid-point. Additionally, regional ionosphere unmodeled residual uncertainty is represented by the form of liner function, which is established by the relationship between distance and interpolation precision through inter-satellite cross-verification among all reference stations. The differences between uncertainty value and real delays are 2.5 cm and 0.5 cm for grid and function forms, respectively. For real-time applications in large areas, the fitting model and grid-based atmosphere uncertainty serve as the essential information, satisfying the requirement of rapid positioning. By further incorporating unmodeled residuals and ionosphere error function, a hierarchical augmentation model is provided. Based on the fitting model established for large areas, unmodeled residuals are further introduced as optional compensation for specific areas, depending on the magnitude of fitting residuals. This approach results in a 97% reduction in tropospheric delay and a 65% reduction in ionospheric delay transmission volume. Furthermore, leveraging the regional high capability of communication, 85.3% of all solutions can achieve instantaneous convergence at the first epoch with the aid of corresponding regional compensation. This thesis proposes a large areas augmentation service to overcome the conflict among correction data volume, represented precision, and coverage size. It demonstrates the benefits of an augmentation mode that integrates regional information into large-area services. Under these conditions, a more reliable and rapid AR solution can be easily achieved based on precise atmospheric delay correction and uncertainty in large areas with fewer data volume requirements. This is beneficial for actual real-time services and applications.

Description: Mit der laufenden Bereitstellung von Bodenstationen für globale Navigationssatellitensysteme (GNSS) und der Modernisierung von Satellitensignal-Systemen ermöglicht die Nutzung verschiedener Augmentationstechnologien die Realisierung der Präzisen Punkt-Positionierung (PPP) in Echtzeit. Augmentationstechnologie, die präzise atmosphärische und signalbezogene Verzögerungen einführt, ist zu einem wesentlichen Bestandteil hochpräziser Echtzeitdienste geworden und findet wachsendes Interesse in wissenschaftlicher Forschung, Katastrophenüberwachung, Autopiloten usw. Frühere Studien haben erhebliche Anstrengungen darauf verwendet, die Erzeugung und Verbreitung von Augmentationsinformationen auf der Dienstseite zu verbessern und Echtzeit-Positionierungsalgorithmen auf der Benutzerseite zu optimieren. Die Echtzeit-Atmosphärenaugmentationsinformationen mit ausreichender Genauigkeit und angemessener Einschränkung sowie zuverlässige Ambiguitätsauflösung (AR) für diesen Zweck stehen im Mittelpunkt der aktuellen GNSS-Forschung. Diese Bemühungen konzentrierten sich jedoch hauptsächlich auf kleine oder mittelgroße Regionen mit der Fähigkeit zur Übertragung großer Datenmengen. Alternativ richteten sie sich auf größere Gebiete, jedoch mit langsamer Konvergenz aufgrund der ungenauen Natur der Atmosphäreninformation. Um der Herausforderung durch die Abwägung zwischen Größe des Dienstleistungsgebiets, Korrekturvolumen und Präzision der dargestellten Korrektur zu begegnen, wird eine neue Augmentationsstrategie vorgeschlagen. Dieser Ansatz integriert die Vorteile atmosphärischer Verzögerungsanpassungsmodelle, nicht modellierter Reste und Unsicherheitsinformationen, um eine schnelle und hochpräzise Positionierung zu erreichen, und das bei gleichzeitiger Reduzierung der Datenübertragungsvolumina für größere Gebiete. Es ermöglicht den Benutzern auch, verschiedene Positionierungsmodi je nach ihrer Kommunikationskapazität zu implementieren. Zusätzlich werden in dieser Studie alle Abweichungen zwischen verschiedenen Typen von Empfängern und Satellitensignalen kalibriert, um eine zuverlässige AR an allen Referenzstationen zu erreichen. Die Hauptbeiträge dieser Arbeit werden wie folgt zusammengefasst. Mit den Echtzeit-Präzbitbahnen, Uhren und Uncalibrated Phase Delay (UPD)-Produkten können präzise atmosphärische Verzögerungskorrekturen für großflächige Augmentationsdienste abgeleitet werden, die auf zuverlässiger AR basieren. Um die Herausforderung zu bewältigen, eine zuverlässige AR über verschiedene Empfängertypen und verschiedene Satellitensignale hinweg zu erreichen, schlägt diese Arbeit eine umfassende Methode zur Kalibrierung von empfängertypbezogenen satellspezifischen Abweichungen vor und analysiert die Auswirkungen von Korrekturen für Satellitensignalverzerrungen in der Datenverarbeitung. Das Hauptziel besteht darin, die Zuverlässigkeit der AR zu verbessern und die Nutzung aller verfügbaren Signale und Empfängertypen in großflächigen Diensten zu ermöglichen. Anschließend werden neue troposphärische und ionosphärische Verzögerungsanpassungsmodelle für großflächige Anwendungen gemäß den Eigenschaften ihrer Ausbreitungspfade durchgeführt. Darüber hinaus wird die entsprechende atmosphärische Verzögerungsunsicherheit für große Gebiete auf der Grundlage der Anpassungsreste eingeführt. Schließlich wird ein hierarchischer Modus für Augmentationsdienste entwickelt, der die Vorteile des Anpassungsmodells und des Unsicherheitsgitters nutzt, um das Datenvolumen zu reduzieren und regionale Anpassungsreste unter Verwendung des Interpolationsmodells und der ionosphärischen Verzögerungsfehlerfunktion, abhängig von der Netzwerkfähigkeit, zu integrieren. Basierend auf der hierarchischen Augmentation kann die Positionierung in großen Gebieten nicht nur eine schnelle/instantane hochpräzise Konvergenz erreichen, sondern auch den Konflikt zwischen Korrekturvolumen, dargestellter Präzision und Abdeckungsgröße überwinden. Um präzise atmosphärische Verzögerungen abzuleiten und die Positionierung zu beschleunigen, ist es entscheidend, eine zuverlässige und robuste AR über alle Arten von Empfängern und Satellitensignalen zu implementieren. Es zeigt auch die Vorteile der Kalibrierung von satellitensignal- und empfängertypbezogenen satellspezifischen Abweichungen in AR-Lösungen auf. Die Abweichungen im Zusammenhang mit Empfängern in Bezug auf UPD-Produkte werden bewertet und kalibriert, wobei bestätigt wird, dass eine Konsistenz von 0,03 Zyklen bei Wide-Lane-UPD erreicht werden kann. Die Wirksamkeit des vorgeschlagenen Ansatzes wird unter Verwendung von GPS-Satellitensignalen demonstriert, die die AR-Rate um mindestens 10% verbessern und zu zuverlässigeren Ergebnissen führen können. Darüber hinaus wird der Einfluss unterschiedlicher Signalparameter und Korrekturen auf die Erzeugung von Orbit, Uhr und UPD sowie auf die Positionierung und systematische und stochastische Reste der Pseudo-Range-Signale analysiert. Diese Verarbeitungsstrategien bieten flexible Auswahlmöglichkeiten bei der Beobachtung und ermöglichen die Nutzung aller verfügbaren Satellitensignale und Empfängertypen, wodurch eine zuverlässige AR und eine höhere Fixierungsrate ermöglicht wird. Als Ergebnis ist eine AR-Fixierungsrate von über 95% bei allen Stationen in großflächigen Diensten erreichbar. Für eine präzise Modellierung atmosphärischer Verzögerungen über großen Gebieten werden neue Modelle vorgeschlagen, darunter ein troposphärisches Zenith Wet Delay (ZWD)-Modell und ein satellitenweises ionosphärisches Schrägverzögerungsanpassungsmodell. Das troposphärische Verzögerungsmodell berücksichtigt die exponentielle Funktion der vertikalen Änderungen des Wasserdampfs und behebt Modellanomalien in Gebieten mit großen Höhendifferenzen. Das neue ionosphärische Verzögerungsanpassungsmodell verwendet trigonometrische Funktionen, um Unterschiede in den Schrägpfadverzögerungen zwischen dem optimalen Referenzausbreitungspfad und anderen zu beschreiben und erreicht so eine überlegene Modellierungsleistung in großen Gebieten. Die Präzision des Anpassungsmodells, unter Verwendung eines 200 km-Stationen-Netzwerks, zeigt troposphärische ZWD- und ionosphärische Schrägverzögerungen von jeweils 1,3 cm und 8,9 cm mit kleineren Standardabweichungen. Diese neuen Anpassungsmodelle überwinden die Herausforderung, massive Informationen für die Bereitstellung stationsspezifischer Korrekturen zu verarbeiten, und vermeiden eine Zunahme der Anzahl der Koeffizienten. Neben dem Funktionsmodell ist das stochastische Modell, d. h. Unsicherheitsinformationen, entscheidend für die Beschreibung der Qualität der Korrekturen. Die Unsicherheit der atmosphärischen Verzögerung für das großflächige Anpassungsmodell wird auf der Grundlage der Anpassungsreste generiert und in Form von Gitterpunkten dargestellt. Zusätzlich wird die regionale ionosphärische nicht modellierte Restunsicherheit durch die Form einer linearen Funktion repräsentiert, die durch die Beziehung zwischen Entfernung und Interpolationsgenauigkeit durch inter-satellitenkreuz-Verifikation zwischen allen Referenzstationen etabliert wird. Die Unterschiede zwischen Unsicherheitswert und realen Verzögerungen betragen 2,5 cm bzw. 0,5 cm für Gitter- und Funktionsformen. Für Echtzeitanwendungen in großen Gebieten dienen das Anpassungsmodell und die gitterbasierte Atmosphärenunsicherheit als wesentliche Informationen, die die Anforderungen an schnelle Positionierung erfüllen. Durch die weitere Integration von nicht modellierten Resten und Ionosphärenfehlerfunktion wird ein hierarchisches Augmentationsmodell bereitgestellt. Basierend auf dem für große Gebiete etablierten Anpassungsmodell werden nicht modellierte Reste zusätzlich als optionale Kompensation für spezifische Bereiche eingeführt, abhängig von der Größenordnung der Anpassungsreste. Dieser Ansatz führt zu einer Reduktion von 97% der troposphärischen Verzögerung und einer Reduktion von 65% des ionosphärischen Verzögerungsvolumens. Darüber hinaus können unter Nutzung der regionalen hohen Kommunikationsfähigkeit 85,3% aller Lösungen mit Hilfe entsprechender regionaler Kompensation eine sofortige Konvergenz beim ersten Epochenzeitpunkt erreichen. Diese Dissertation schlägt einen großflächigen Augmentationsdienst vor, um den Konflikt zwischen Korrekturvolumen, dargestellter Präzision und Abdeckungsgröße zu überwinden. Sie zeigt die Vorteile eines Augmentationsmodus, der regionale Informationen in großflächige Dienste integriert. Unter diesen Bedingungen kann eine zuverlässigere und schnellere AR-Lösung basierend auf präziser atmosphärischer Verzögerungskorrektur und Unsicherheit in großen Gebieten mit geringeren Anforderungen an das Datenvolumen leicht erreicht werden. Dies ist vorteilhaft für tatsächliche Echtzeitdienste und Anwendungen.

Description: Present day system Earth research utilizes the tool ‘Scientific Drilling’ to access samples and to monitor deep Earth processes that cannot be tackled by other scientific means. Unlike most laboratory experiments or computer modelling, drilling projects are massive field endeavours requiring intense collaboration of researchers with engineers and service providers. In the framework of the International Continental Scientific Drilling Program, ICDP, more than seventy drilling projects have been conducted, from multiyear big research programs to short, smallscale deployments such as lake drilling projects. ICDP has supported these projects not only through grants covering field-related costs, but also through a variety of scientific-technical services and support, as well as active help in data management, outreach and publication. These services are described in this booklet. Due to its instructional character, we call it the ICDP Primer.

Description: Deliverable D2.3 reports the work performed in task 2.3 “Metal complexation and mineral precipitation” within the Reflect project. The task is divided into the subtasks 2.3.1 “Mineral solubility and precipitation kinetics”, 2.3.2 “Mineral precipitation by impedance spectroscopy” and 2.3.3 “Modelling mineral solubility”. A combination of experimental design, performed experiments and numerical modelling have increased the knowledge of mineral solubility and precipitation at high salinity condition in geothermal fluids.

Description: The Mallik Anticline is a geologic structure in the Mackenzie Delta in the Canadian Arctic. Tectonics throughout the Cenozoic, with compressional phases in the early Eocene to the late Miocene, formed this large, domed structure that is today an important source of hydrocarbons. Gas hydrates occur in the clastic sedimentary rocks of the Oligocene to Pleistocene Kugmallite, Mackenzie Bay, and Iperk sequences, which were essentially formed by deltaic processes. The presence of hydrocarbon gases within the permafrost zone in the Canadian Arctic has led to extensive exploration and production activities in the region since the mid-1960s, and the investigations by geologists and geophysicists have already been published in numerous scientific articles to date. This report describes the implementation of the first field-scale 3D static geologic model of the Mallik site, which was created using data from well logs and 2D seismic reflection profiles. The dataset related to this report provides elevation depths and thickness data of the three distinct sequence boundaries Kugmallit-Richards, Mackenzie Bay-Kugmallit and Iperk-Mackenzie Bay as well as fault data from the Mallik site.

Description: The classical way to model the stress state in a rock volume is to estimate displacement boundary conditions that minimize the deviation of the modelled stress state with respect to model-independent stress information such as stress magnitude data. However, these data records are usually subject to significant uncertainties and measurement errors. Hence, it has to be expected that not all stress magnitude data records are representative and can be used in a model. In order to identify unreliable stress data records, the stress state that is based on individual data records is solved and compared with observations at a few discrete locations. While this method works, it is not efficient in that most of the solved model scenarios will be discarded. The solving of the entire model consumes immense amount of computation time for a high-resolution model. Yet, the stress state is required at only a very limited number of locations. For linear geomechanical models it is sufficient to estimate the stress state from three model scenarios with arbitrary, but different displacement boundary conditions. These three results can be used to estimate analytically using a linear regression at discrete points stress states based on user-defined boundary conditions. The tool Fast Automatic Stress Tensor Estimation (FAST Estimation) is a Python function that automatizes this approach. FAST Estimation provides very efficiently the stress states at pre-defined locations for all possible boundary conditions. It does not provide the continuous stress field as provided by a solved geomechanical model. Instead, it is a cost-efficient solution for the rapid assessment of stress states at a limited number of discrete locations based on pre-defined boundary conditions.

Description: During weathering of the deep rocks, many actors act together. This is a property characteristic of the entire “Earth system”. For example, fractures open up, through which water flows that carries carbon and reagants with it from above. New minerals are formed and open up further fractures. Large fractures are also a gateway for microbes from above. They multiply at depths where there is carbon and iron is oxidised. The explorer Alexander von Humboldt stated “Everything is interaction”. Under and on the earth. In our example, soil is created.

Description: Weathering needs fractures in the rock. When two tectonic plates collide, the plates slide against each other. During earthquakes fractures in the rock are created. The microscope reveals tiny cracks running through the rock. These micro-fractures are caused by the movement of the rocks against each other, but also when erosion at the Earth's surface removes the burden of the overlying rock. Fractures are necessary to bring water, reagents, and microbes to depth to weather rocks.

Description: To weather rock, reagents are required. For example, CO2 is found in rainwater as carbonic acid or CO2 is produced by plant roots and by microbes. Through the large fractures carbonic acid and CO2 reach great depth – dissolved in water. Through the fine fractures they reach the interior of the rock. There they dissolve minerals, like the feldspar. New, completely different minerals form, for example clay minerals. They create fine fractures through which water with carbon can penetrate further and the weathering begins again.

Description: Weathering of rock needs water. A rock fractured by tectonic movement is gradually eroded from above, and it moves closer towards the Earth's surface. There it is exposed to precipitation and water begins to penetrate the soil and the layers beneath the soil. Through the tectonic fractures, the water can reach great depths. This is a rapid transport process. At a millimetre scale the water slowly moves into the interior along the smallest cracks that occur there. This is a slow transport process. The water can now weather rocks from the inside.

Description: Living organisms can also weather rocks. There are microorganisms in deep rock – in the "deep biosphere". With flowing water, the microbes are transported from soil through the fractures to depth. Down there, in complete darkness, the microbes live on water, carbon, and energy. They can oxidise iron in minerals and receive energy in the process. The iron-containing minerals are oxidised, carbon is consumed, and more and more microbes are created. This is how the deep biosphere keeps itself alive and weathers the rock at the same time.

Description: An unbelievable crime is discovered in a storage facility. Rocks have been murdered! Detective Hercule Poirot takes up the investigation. He hires a group of international geo-researchers to search for the "suspects" in a drilling campaign in the spectacular landscapes of Chile. They find evidence of the crime in research laboratories - and present a surprising solution to the murder case. The film addresses a scientific question: how does weathering deep below the Earth's surface turn rock into soil? The four "suspects" (meaning processes) - fractures in the rock, water flow, chemical reagents, and microbes are seen in action in animations. However, they only serve as hypotheses that cannot be directly proven. They can only be shown to be false – just like an alibi in a criminal case. Watch the movie to see whether the researchers succeed. The film was produced as part of the German-Chilean project "EarthShape – Earth Surface Shaping by Biota". Another video can be seen here: The Skin of the Earth - Where Life Meets Rocks

Description: This report presents the European High-Resolution Exposure (EHRE) model, which we created by combining the state-of-the art exposure model of the European Seismic Risk Model 2020 (ESRM20) with building footprints and data from OpenStreetMap previously processed by OpenBuildingMap. We present the method used to generate the model and the software we developed for this purpose, as well as a number of outputs that give an overview of what the model consists of and enable discussion.

Description: This deliverable summarizes the optimization workflow to determine the optimum operational controls for the geothermal assets operation considering the uncertainties in the brine composition. The developed models for coupling hydrodynamics with chemistry and uncertainty quantification workflow for estimating the risk of scaling in geothermal plants were integrated with a stochastic optimization model. Results showed the demonstration of such an integrated workflow applied to a scaling precipitation case study and possible variations in operational decisions due to uncertainties in the brine composition.

Description: This document presents the application of coupled hydrogeochemical codes to the modelling of geothermal fluid reactivity in tubings during the production of geothermal energy. Two codes are used on two examples of fluids: one is very concentrated with a moderate temperature (no phase changes during the pumping) and one hot fluid with a lower salinity (with phase change). Results focus on the risks of scaling during the exploitation.

Description: Risk maps are created with the objective of providing improved operational advice on scaling mitigation. The issue of prevailing uncertainties and variations in fluid and gas data had to be tackled to provide accurate model predictions and risk assessments. The developed risk map workflow is demonstrated for calcite scaling risks of the West-Netherlands Basin.

Description: The Collisional Orogeny in the Scandinavian Caledonides (COSC) scientific drilling project characterises the structure and orogenic processes involved in a major collisional mountain belt by multi-disciplinary geoscientific research. Located in western central Sweden, the project has drilled its second fully cored borehole COSC-2 in 2020. It extends the COSC composite geological section through the nappes of the Caledonian Lower Allochthon, the main décollement and the upper kilometre of basement rocks. COSC-2 targets include the characterisation of orogen-scale detachments, the impact of orogenesis on the basement below the detachment, and the Early Cambrian palaeoenvironment on the outer margin of palaeocontinent Baltica. This is complemented by research on heat flow, groundwater flow, and characterisation of the microbial community in the present hard rock environment of the relict mountain belt. COSC-2 successfully and within budget recovered a continuous drill core to 2276 m depth. The retrieved geological section is partially different from the expected geological section with respect to the depth to the main décollement and the expected rock types. The intensity of deformation in the rocks in the upper part of the drill core might impede the analysis of the Early Cambrian palaeoenvironment. However, the superb quality of the drill core and the borehole will facilitate research on the remaining targets and beyond. Although on-site science was reduced due to Covid-19 related restrictions, COSC-2 drilling was complemented by extensive downhole surveys. However, the geological description of the drill core and the sampling party were severely delayed, with the later being held about two years after drilling, concluding the operational phase of the project.

Description: This report describes the activities performed within Task 1.2 “Report on gas solubility and degassing kinetic (type C)” until the end of month 40 of the REFLECT project. Two series of experiments have been carried out that assess the degassing process of type C geothermal fluids respectively in bulk and porous media. This has resulted in an improved understanding of the process and the associated physical phenomena by utilizing experimental equipment and data analysis tools specifically created for this task.

Description: This report describes the activities performed within Task 1.3 “Summary of gas solubility and degassing kinetics (type A)” until the end of month 39 of the REFLECT project. Two series of experiments have been carried out that assess the degassing process of type A geothermal fluids respectively in bulk and porous media. This has resulted in an improved understanding of the process and the associated physical phenomena by utilizing experimental equipment and data analysis tools specifically created for this task.

Description: All datasets provided in the operational dataset (DOVE-Phase 1 Scientific Team et al., 2023b) of the ICDP project DOVE phase 1 (ICDP 5068) consist of metadata, data and/or images. Here, we summarize explanations on the tables, data and images exported from the database of the project (mDIS DOVE) as well as some basic explanations on identifiers used in ICDP, depths corrections and measurements that are integrated into the dataset.

Description: A detailed understanding of the geological structural elements is vital for geothermal reservoir exploration. Among existing geophysical methods, seismic methods are most commonly used for subsurface imaging due to the relatively high resolution at significant depths. However, seismic campaigns are rather expensive. The high upfront investment cost represent a substantial barrier for heat/electricity production from geothermal resources. Thus, developing new techniques is vital for further reduction in exploration and drilling costs, which is necessary for geothermal project advancements. Within the framework of the joint research project RissDom-A, the subsurface exploration of the Groß Schönebeck in-situ geothermal laboratory, situated 40 km north of Berlin, a seismic survey was carried out using 3D surface seismic and 3D vertical seismic profiling methods. VSP was acquired with wireline distributed acoustic sensing (DAS), which allows converting a freely suspended fibre optic cable inside a borehole into a dense array of seismic sensors to record strain or strain rate. In this thesis, the applicability of this method is evaluated for seismic imaging of an enhanced geothermal reservoir. The survey design consisted of 61 vibrator source positions organised in a spiral pattern around the boreholes E GrSk 3/90 and Gt GrSk 4/05 in such a way to optimise the illumination of the reservoir. The DAS recordings have an excellent signal-to-noise ratio (40-50 dB around 1000 m, 4-10 dB at around 4200 m). This data quality was reached with 16 vertical stacking rates on average. In addition, a comparison with a conventional accelerometer measurement showed excellent waveforms agreement. The acquisition campaign was conducted within four days, illustrating that wireline DAS is very attractive both from a data quality point of view and economically. A 3D VSP processing workflow was adapted to the Groß Schönebeck specifics and applied to the data. Particular depth ranges of the recorded data are subjected to strong coherent noise, which has a distinct pattern both in the time and the frequency domain. This type of noise is related to the poor coupling conditions of the cable in the borehole. For signal-to-noise ratio improvement, several existing denoising methods have been analysed. After coupling noise filter function assessment, a new noise elimination method was proposed based on the matching pursuit decomposition technique with Gabor atoms. The developed processing routine was uniformly applied to the whole dataset, which significantly improved the data quality, and as a result, migration images created using the Kirchhoff depth migration algorithm with restricted aperture. After data processing, a detailed subsurface analysis in the vicinity of the boreholes at the Groß Schönebeck was carried out using the 3D DAS VSP image. The resulting borehole cube data resolve new features that could not be imaged with the 3D surface seismic cube due to the lower resolution of the 3D surface seismic cube, with respect to the 3D VSP cube. Complex thin interlaying of the Upper Rotliegend horizons has been revealed in the geothermal reservoir section, allowing for the first time to access and characterise so-called “phantom horizons” which are typical for the Brandenburg area, Germany. Furthermore, the borehole cube provided new insights on two main targets for future exploration. The 3D DAS VSP cube revealed an intra-reservoir structure inside the Elbe reservoir sandstone layer, which could represent porous parts of a stacked fluvial sandstone body. The estimated thickness of this structure varies between 25 to 40 m, which is thinner than previous estimations. Additionally, a lower Rotliegend unconformity (at around 4.2 km depth) was mapped in the study area. This allowed to estimate the possible thickness of the vulcanite sections below this boundary. VSP data thus helped to reduce the uncertainty and exploration risks by providing valuable information for the geological characterisation of the Groß Schönebeck site. With this successful case study I demonstrated that fibre optic data could significantly contribute to the characterisation of deep geothermal reservoirs. Consequently, presented results contribute to the wireline distributed acoustic sensing method promotion to develop modern, reliable and economically affordable exploration methods for geothermal energy assessments.

Description: Ein detailliertes Verständnis der geologischen Strukturelemente ist für die Erkundung geothermischer Reservoire unerlässlich. Unter den bekannten geophysikalischen Methoden werden vor allem seismische Untersuchungen zur Abbildung des Untergrunds aufgrund der vergleichsweise hohen Auflösung bis in große Tiefen genutzt. Seismikkampagnen sind jedoch verhältnismäßig teuer. Die hohen Anfangsinvestitionskosten bilden eine erhebliche Hürde für die Wärme- und Stromproduktion aus geothermischen Ressourcen. Daher ist die Entwicklung neuer Techniken zur Reduktion von Exploarations- und Bohrkosten für die notwendige Förderung geothermischer Projekte essenziell. Im Rahmen des Verbundforschungsprojekts RissDom-A, der Untergrunderkundung des 40 km nördlich von Berlin gelegenen Groß Schönebeck in-situ Geothermielabors, wurden seismische Messungen durchgeführt, bestehend aus einer 3D-Oberflächen- und einer 3D-Bohrlochseismik. Die VSP-Daten (Vertical Seismic Profiling) wurden mittels kabelgebundenem DAS (Wireline Distributed Acoustic Sensing) aufgezeichnet, was die Umwandlung eines frei im Bohrloch hängenden faseroptischen Kabels in ein dichtes Array seismischer Sensoren zur Registrierung von Strain oder Strain-Rate erlaubt. In dieser Doktorarbeit wird die Anwendbarkeit dieser Methodik für die seismische Abbildung von EGS-Reservoiren (Enhanced Geothermal System) eingehend ausgewertet. Die Messkonfiguration bestand aus 61 Vibrator-Quellpositionen, die in einem spiralförmigen Pattern um die beiden Bohrlöcher E GrSk 3/90 und Gt GrSk 4/05 derart verteilt wurden, dass eine optimale Durchschallung des Reservoirs gegeben war. Die DAS-Aufzeichnungen zeigen ein exzellentes Signal/Rausch-Verhältnis (40-50 dB bei ca. 1000 m, 4-10 dB bei ca. 4200 m). Diese Datenqualität konnte aufgrund der durchschnittlich 16-fachen vertikalen Stapelrate erzielt werden. Zu Vergleichswecken zusätzlich vorgenommene konventionelle Beschleunigungsaufnehmer- Messungen zeigen eine sehr gute Übereinstimmung der Wellenformen. Die Messkampagne umfasste vier Tage, was die Attraktivität von Wireline-DAS unter sowohl qualitativen als auch ökonomischen Aspekten überzeugend demonstriert. Eine 3D-VSP Bearbeitungssequenz wurde an die Besonderheiten der Groß Schönebeck Messungen angepasst und auf die Daten angewendet. Einzelne Tiefenbereiche der Aufzeichnungen enthalten starke kohärente Störsignale, die ein ausgeprägtes Muster sowohl im Zeitals auch im Frequenzbereich aufweisen. Diese Art Noise ist auf eine ungenügende Ankopplung des Kabels im Bohrloch zurückzuführen. Zur Verbesserung des Signal/Rausch-Verhältnisses wurden verschiedene gebräuchliche Unterdrückungsmethoden untersucht. Nach Analyse der Kopplungsnoise-Filterfunktion konnte eine neuartige Methode zur Rauschunterdrückung etabliert werden, welche auf einer Matching-Pursuit Dekompositionstechnik mit Gabor-Atomen basiert. Der auf diese Weise entwickelte Prozessierungsansatz wurde gleichmäßig auf den gesamten Datensatz angewendet, was die Datenqualität signifikant erhöhte, so dass in der Folge Migrationsabbilder unter Verwendung eines Kirchhoff-Tiefenmigrationsverfahrens mit beschränkter Apertur erzeugt werden konnten. Nach erfolgter Datenbearbeitung wurde anhand der DAS/VSP 3D-Daten eine detaillierte Untergrundanalyse im Bereich der Groß Schönebeck Bohrlöcher durchgeführt. Das resultierende Bohrlochaten-Volumen löst viele neue Details auf, die mit dem 3D-Volumen der Oberflächenseismik aufgrund des vergleichsweise geringeren Auflösungsvermögens nicht abgebildet wurden. So konnten in der geothermischen Reservoirsektion komplexe dünnschichtige Einlagerungen im Oberen Rotliegend nachgewiesen werden, die erstmalig die Ansprache und Charakterisierung sogenannter „Phantom-Horizonte“ ermöglichen, wie sie typisch für das Gebiet Brandenburg, Deutschland sind. Weiterhin liefert der Bohrlochdaten-Kubus neue Einblicke auf zwei Hauptziele zukünftiger Explorationen. Das DAS/VSP 3D-Datenvolumen zeigt eine Intra-Reservoir Strukur innerhalb der Elbe-Sandstein Schicht, die poröse Anteile eines gestapelten fluvialen Sandsteinkörpers repräsentieren könnte. Die geschätzte Mächtigkeit dieser Struktur variiert zwischen 25 und 40 m, was dünner ist, als zuvor angenommen. Des weiteren konnte im Untersuchungsgebiet eine Diskordanz im Unteren Rotliegend (in einer Tiefe von ca 4.2 km) kartiert werden. Dies erlaubt es, die mögliche Mächtigkeit der Vulkanite darunter abzuschätzen. Somit helfen die VSP-Daten dabei, die Unklarheiten und das Explorationsrisiko zu reduzieren, indem sie wertvolle Informationen zur geologischen Charakterisierung des Groß Schönebeck Standorts liefern. Mit dieser Fallstudie konnte ich erfolgreich demonstrieren, dass mithilfe faseroptischen Kabels gewonnene Messdaten zur Charakterisierung geothermischer Reservoire maßgeblich beitragen können. In der Konsequenz fördern die präsentierten Ergebnisse die Bedeutung von Wireline Distributed Acoustic Sensing im Hinblick auf eine moderne, verlässliche und ökonomische Explorationsmethode für geothermische Energiekonzepte.

Description: The 3D geomechanical-numerical modelling aims at a continuous description of the stress state in a subsurface volume. The model is fitted to the model-independent stress data records by adaptation of the displacement boundary conditions. This process is herein referred to as model calibration. Depending on the amount of available stress data records and the complexity of the model the calibration can be a lengthy process of trial-and-error to estimate the best-fit boundary conditions. The tool FAST Calibration (Fast Automatic Stress Tensor Calibration) is a Matlab script that facilitates and speeds up this calibration process. By using a linear regression it requires only three test model scenarios with different displacement boundary conditions to calibrate a geomechanical-numerical model on available stress data records. The differences between the modelled and observed stresses are used for the linear regression that allows to compute the displacement boundary conditions required for the best-fit estimation. The influence of observed stress data records on the best-fit displacement boundary conditions can be weighted. Furthermore, FAST Calibration provides a cross checking of the best-fit estimate against indirect stress information that cannot be used for the calibration process, such as the observation of borehole breakouts or drilling induced fractures. In order to bridge the scale gap between a regional stress model and a local reservoir model, the multistage calibration procedure is applied where a local model is calibrated solely on the stress state provided by a regional model. FAST Calibration provides the necessary tools and guidelines. The script files are provided for download at http://github.com/MorZieg/FAST_Calibration. Tab. 0-1 gives an overview of the folder structure and input files with a short explanation.

Description: This report documents the drilling operations of the Early Jurassic Earth System and Timescale scientific drilling project (JET, ICDP Project: 5065). The wells 5065_1_A, 5065_1_B, 5065_1_A were drilled in 2019-2021 with the support of the International Continental Scientific Drilling Program (ICDP) and the UK Natural Environment Research Council (NERC). Alternatively, the site is known as Prees 2 (Holes A – C). Prees 1 was a nearby hydrocarbon exploration well drilled by Trend Petroleum in 1972–1973. The project aims to construct a fully integrated and astronomically calibrated timescale for the Early Jurassic, a time in Earth history during which important physical, chemical, and biological elements of the modern Earth system were initiated. The JET drilling campaign supplements the earlier Llanbedr (Mochras Farm) borehole (1967 – 1969) in NW Wales – usually known as Mo-chras – which recovered a 1.3 km thick succession comprising the Rhaetian (Upper Triassic), Hettangian, Sinemurian, Pliensbachian and Toarcian (Lower Jurassic) stages (Woodland, 1971; Hesselbo et al., 2013). Using the combined framework of Prees and Mochras, internal and ex-ternal forcing factors on the Earth system will be documented and quantified for major palaeo-environmental events, such as the Late Triassic mass extinction and the Early Toarcian Oceanic Anoxic Event, and for the more stable ‘background’ state.

Description: Two recent tsunamis in late 2018, in Sulawesi and Anak Krakatau, Indonesia, strikingly demonstrated the high vulnerability of communities to tsunamis induced by landslides and volcanic mechanisms. Both tsunamis were the result of a chain (cascade) of events: on 28 September in Palu, on the island of Sulawesi, the cascade consisted of a sequence of earthquake - landslide - tsunami, while on 22 December, after a prolonged period of volcanic activity, a flank failure occurred on Anak Krakatau, which in turn triggered a tsunami (Walter et al, 2019). In both cases, the resulting tsunamis caught the local population largely unprepared and caused a high number of fatalities. This has been attributed to the limited understanding of tsunami generation from mechanisms other than fault rupture and the lack of an effective tsunami warning system for non-seismic events. Both events have raised questions in the Indonesian society and among the relevant authorities about appropriate strategies for improved preparedness, early warning and mitigation for such events. The German-Indonesian project "TsunamiRisk" aims to help answer these questions through applied geoscientific and social science research aimed at developing policy recommendations and enabling transfer into practice. The perspective of local communities must be given special consideration, as it is ultimately they who are confronted with the direct impacts of such events on the one hand and who must implement better preparation and long-term mitigation on the ground on the other. Therefore, the project investigates the specific framework conditions as well as existing experiences in Indonesian communities with previous earthquake/tsunami events in order to support the discussion about adequate strategies and approaches for preparedness, early warning and mitigation of non-seismic tsunami hazards at the local level. The starting point for all this is to have a better understanding of the tsunami threats that communities face. The present study is intended to make a contribution to this.

Description: This deliverable contains the raw data that constitutes the database of microbial diversity and organic compounds in geothermal fluids used for electricity production generated during the project.

Description: Report of design and test results of downhole sampling.

Description: We provide new thermodynamic and kinetic data concerning the dissolution and precipitation of silica in hot and superhot geothermal systems. Different methods were applied, including traditional photometric methods and in situ Raman and conductimetric methods. The studies covered the interactions of silica with both pure water and saline solutions. The kinetics of silica polymerisation were studied in the presence of various metal ions and at different pH values, informed by an analysis of real geothermal water samples from the Tuzla region of Türkiye.

Description: This dataset contain stable isotope values for water samples collected ~weekly from the Rio Bermejo at the Lavalle bridge (-25.6513, -60.1277) from March 2016 to February 2018. Water samples were filtered to 0.2 micron using a custom filtration device. We measured d2H and d18O on a Picarro L-2140i Cavity Ring-Down Spectrometer at the GFZ Potsdam. Measurements were made in duplicate, normalized to the Vienna Standard Mean Ocean Water (VSMOW), and analytical uncertainty is reported as one standard deviation from the mean. River discharge was measured at the El Colorado gauging station, which is ~100 km down slope from the sampling location.

Description: This dataset provides the geochemistry data for the Holocene sediment sequence retrieved from Lake Uddelermeer (The Netherlands) in 2012. Additionally, alkane concentrations for a set of modern leaf samples are provided. Concentrations of fossil alkanes, GDGTs as well as elemental (C, N, S, H) and compound-specific delta Deuterium measurements are presented against both depth (cm) and age (cal yr. BP). A total of 59 samples were analysed. Modern leaf alkane concentrations are presented as concentrations, 10 samples were analysed. The geochemical data provides information about regional vegetation change as well as changes in effective precipitation. It was produced to inform on the age and duration of major environmental transitions during the middle and late Holocene. Cores were retrieved from the lake using a 3-m long handheld piston corer deployed from a floating coring platform during field work in April and May 2012. Samples were obtained from splits of the core and processed in the laboratory of the University of Amsterdam (the Netherlands) using standard protocols (CNHS, alkane concentrations), the laboratory of Utrecht University (the Netherlands; GDGT concentrations) and at GFZ Potsdam (Germany; delta Deuterium). Name of the Campaign: UDD Event Label: UDD-E Method: Uwitec piston corer Latitude: 52.24652778 Longitude: 5.76097222 Elevation: 24m asl Date/Time of event: 2012-05-01T14:00:00 Further information about event: Lake sediment sequence retrieved using a 60 mm piston corer deployed from a floating platform.

Description: Water samples were filtered to 0.2 micron prior to measurement. Samples for cation analysis were acidified in the field to pH 〈 2 using 6N HNO3. Cation concentrations were measured with a Varian 720 inductively coupled plasma optical emission spectrometer (ICP-OES) at the GFZ Helmholtz Laboratory for the Geochemistry of the Earth Surface (HELGES), using SLRS-5 (Saint-Laurent River Surface, National Research Council - Conseil National de Recherches Canada) and USGS M212 and USGS T187 as external standards. We corrected for instrument drift by measuring an internal standard (GFZ-RW1) every 10 samples and we determined measurement uncertainty using calibration curve uncertainty. Anion concentrations were measured with a Dionex ICS1100 Ion Chromatograph, using USGS standards M206 and M212 as external standards for quality control, with uncertainty determined from triplicate analysis. We corrected cation concentrations for cyclic salt inputs following Bickle et al. (2005, doi:10.1016/j.gca.2004.11.019).

Description: The International Celestial Reference System (ICRS) is the reference system used for astrometry and geodesy in space. Its realizations are the International Celestial Reference Frames (ICRFs). The latest realizations are ICRF3 S/X, ICRF3 K, and ICRF3 X/Ka at radio frequencies observed by geodetic very long bThe International Celestial Reference System (ICRS) is the reference system used for astrometry and geodesy in space. Its realizations are the International Celestial Reference Frames (ICRFs). The latest realizations are ICRF3 S/X, ICRF3 K, and ICRF3 X/Ka at radio frequencies observed by geodetic very long baseline interferometry (VLBI), and Gaia-CRF3 from observations by the Gaia spacecraft at optical frequencies. The ICRFs are independently derived catalogs of mean positions (and proper motions as well as parallaxes in case of Gaia) of distant compact extragalactic sources with approximately comparable precision. Within the error bounds, the different observation setups should ideally produce identical source positions. However, previous research discovered variances related to the variable nature of the sources as a function of frequency and time. A deeper understanding of the individual source position differences as well as the alignment of the ICRFs in terms of global systematic source position differences benefits the large ICRF and Gaia user community, such as geodetic VLBI for connecting VLBI products across frequencies. This work adds several case studies to the existing research on the comparison and the alignment of the ICRFs. At optical frequencies, the set of ICRF3 counterparts in the Gaia spacecraft’s Early Data Release 3 (Gaia EDR3, including Gaia-CRF3) and in Gaia DR2, the predecessor of Gaia EDR3, are investigated. The position differences of the individual counterparts at the various frequencies are re-evaluated, focusing on the correlation of the normalized distances, offset directions, and global systematic differences with the number of VLBI observations or the extent of radio source structure. The individual VLBI and Gaia position offsets tend to be in the same direction, especially in case of significant offsets. It is shown that large normalized position offsets are related to sources with large radio structure. The global systematic differences, which are an order of magnitude smaller than the individual differences, can be accurately determined, especially if the set of counterparts has been defined. A Celestial Reference Frame (CRF) determined from S/X observations from the same time interval as Gaia DR2 does not indicate any improvements in the alignment of Gaia DR2 compared to ICRF3 S/X. Since the alignment of Gaia DR2 and Gaia EDR3 depends on the visual magnitude G and the radio sources in ICRF3 are optically faint, the alignment of the bright fraction (G ≤ 13 mag) of the Gaia data releases to ICRF3 requires additional verification. The approach and data of Lindegren (2020a) are adopted, who used optically bright radio stars to test the alignment. Since the resolution of VLBI and Gaia is small enough to detect their proper motions, they must be included in the alignment test and a time variability of the alignment (spin) must also be estimated. However, these results are not yet accurate enough compared to the expected uncertainties of the individual sources astrometry in the final Gaia data release for this G magnitude range. In this work, these VLBI data of radio stars are homogenized, and a more realistic error budget for the VLBI positions is established. New, dedicated VLBI observations of bright radio stars were carried out to obtain more urgently needed VLBI positions for the determination of the alignment. The positions are included in two ways: once as absolute one-epoch positions and once as relative positions in order to derive new precise models of stellar motion whenever possible. A significant spin around the Y axis was determined for both Gaia DR2 and Gaia EDR3, albeit the rotations in this direction are still the least well determined. Among other aspects, the accuracy of the results, the effect of nonlinear proper motion, and a G magnitude dependence within the bright fraction are investigated. The effect of possible future VLBI observations of radio stars on the alignment is tested. In summary, this work evaluates the accuracy of the alignment of the current ICRFs. It furthermore highlights the need to accurately assess VLBI observations of radio stars in the context of the alignment of the Gaia bright frame with ICRF3 and demonstrates how this can be accomplished.

Description: Das International Celestial Reference System (ICRS) ist das Himmelsreferenzsystem, das in der Astrometrie und Geodäsie verwendet wird. Seine Realisierungen sind die International Celestial Reference Frames (ICRFs). Die jüngsten Realisierungen sind im Radiofrequenzbereich der ICRF3 S/X, der ICRF3 K und der ICRF3 X/Ka, welche mit Hilfe von geodätischer very long baseline interferometry (VLBI) beobachtet werden. Außerdem ist es im optischen Frequenzbereich der Gaia-CRF3, welcher aus Beobachtungen des Gaia Weltraumteleskops stammt. DDas International Celestial Reference System (ICRS) ist das Himmelsreferenzsystem, das in der Astrometrie und Geodäsie verwendet wird. Seine Realisierungen sind die International Celestial Reference Frames (ICRFs). Die jüngsten Realisierungen sind im Radiofrequenzbereich der ICRF3 S/X, der ICRF3 K und der ICRF3 X/Ka, welche mit Hilfe von geodätischer very long baseline interferometry (VLBI) beobachtet werden. Außerdem ist es im optischen Frequenzbereich der Gaia-CRF3, welcher aus Beobachtungen des Gaia Weltraumteleskops stammt. Die ICRFs sind unabhängig voneinander abgeleitete Kataloge mittlerer Positionen (und Eigenbewegungen als auch Parallaxen im Falle von Gaia) entfernter kompakter extragalaktischer Quellen mit annähernd vergleichbarer Genauigkeit. Innerhalb der Fehlergrenzen sollten die verschiedenen Beobachtungsmethodiken idealerweise zu identischen Quellenpositionen führen. In früheren Untersuchungen wurden jedoch Abweichungen festgestellt, die mit der frequenz- und zeitvariablen Quellenstruktur zusammenhängen. Ein tieferes Verständnis der individuellen Positionsunterscheide der Quellen als auch der Unterschiede in der Orientierung der ICRFs mittels globaler systematischer Positionsunterschiede der Quellen kommt der großen Nutzergruppe von ICRF und Gaia zugute, wie z. B. der geodätischen VLBI für die Zusammenführung von VLBI-Produkten über Frequenzen hinweg. Diese Arbeit ergänzt die bestehenden Forschungsarbeiten über den Vergleich und die Orientierung der ICRFs um mehrere Fallstudien. Im optischen Frequenzbereich werden die ICRF3-Gegenstücke im Early Data Release 3 (Gaia EDR3, einschließlich Gaia-CRF3) der Gaia Raumsonde und im Gaia DR2, dem Vorgänger von Gaia EDR3, untersucht. Die Positionsunterschiede der einzelnen Gegenstücke für die verschiedenen Frequenzen werden neu bewertet, wobei der Schwerpunkt auf der Korrelation der normalisierten Entfernungen, der Richtungen der Positionsdifferenzen und der globalen systematischen Unterschiede mit der Anzahl der VLBI-Beobachtungen sowie dem Ausmaß der Radioquellenstruktur liegt. Die individuellen VLBI- und Gaia-Positionsunterschiede bevorzugen die selbe Richtung, insbesondere im Falle signifikanter Differenzen. Es wird gezeigt, dass große normalisierte Positionsunterschiede auf Quellen mit großer Radioquellenstruktur zurückzuführen sind. Die globalen systematischen Abweichungen, die um eine Größenordnung geringer sind als die individuellen Differenzen, können genau bestimmt werden. Dies gilt insbesondere wenn die Teilmenge der verwendeten Gegenstücke vorher definiert wurde. Ein Celestial Reference Frame (CRF), der aus S/X-Beobachtungen des selben Zeitintervalls wie Gaia DR2 ermittelt wurde, zeigt keine Verbesserungen in der Ausrichtung von Gaia DR2 im Vergleich zu ICRF3 S/X. Da die Orientierung von Gaia DR2 und Gaia EDR3 von der scheinbaren Helligkeit G ab- hängt und die Radioquellen des ICRF3 eine geringe scheinbare Helligkeit aufweisen, muss die Ausrichtung des hellen Anteils (G ≤ 13 mag) der Gaia-Daten auf den ICRF3 zusätzlich überprüft werden. In dieser Arbeit werden der Ansatz und die Daten von Lindegren (2020a) übernommen, der zur Überprüfung der Orientierung scheinbar helle Radiosterne verwendete. Da die Auflösung von VLBI und Gaia klein genug ist, um Eigenbewegungen von Sternen zu erkennen, müssen diese in den Orientierungstest einbezogen und auch eine zeitliche Variabilität der Orientierung geschätzt werden. Allerdings sind diese Ergebnisse bisher nicht genau genug im Vergleich zu den erwarteten Genauigkeiten der Astrometrie der einzelnen Quellen des hellen Anteils in der endgültigen Gaia-Datenveröffentlichung. In dieser Arbeit werden die vorhandenen VLBI-Daten der Radiosterne homogenisiert und es wird ein realistischeres Fehlerbudget für die VLBI-Positionen aufgestellt. Es wurden neue, gezielte VLBI-Beob-achtungen von hellen Radiosternen durchgeführt, um mehr dringend benötigte VLBI-Positionen für eine bessere Bestimmung der Orientierung zu erhalten. Die Positionen wurden auf zwei verschiedene Arten integriert: einmal als absolute Positionen aus einer Beobachtungsepoche und einmal als relative Positionen, um wann immer möglich neue präzise Modelle der Sternbewegung abzuleiten. Sowohl für Gaia DR2 als auch für Gaia EDR3 wurde eine signifikante zeitabhängige lineare Rotation um die Y -Achse ermittelt, wenngleich die Rotationen in dieser Richtung noch die geringste Genauigkeit aufweisen. Unter anderem werden die Genauigkeit der Ergebnisse, die Auswirkung der nichtlinearen Eigenbewegung und die Abhängigkeit von der scheinbaren Helligkeit innerhalb des hellen Anteils untersucht. Der Einfluss möglicher zukünftiger VLBI-Beobachtungen von Radiosternen auf die Orientierungsbestimmung wird getestet. Zusammenfassend evaluiert diese Arbeit die Genauigkeit der Orientierung der aktuellen ICRFs. Sie unterstreicht darüber hinaus die Notwendigkeit, VLBI-Beobachtungen von Radiosternen im Zusammenhang mit der Orientierung des hellen Gaia-Referenzrahmens zu ICRF3 genau zu prüfen, und zeigt, wie dies erreicht werden kann.ie ICRFs sind unabhängig voneinander abgeleitete Kataloge mittlerer Positionen (und Eigenbewegungen als auch Parallaxen im Falle von Gaia) entfernter kompakter extragalaktischer Quellen mit annähernd vergleichbarer Genauigkeit. Innerhalb der Fehlergrenzen sollten die verschiedenen Beobachtungsmethodiken idealerweise zu identischen Quellenpositionen führen. In früheren Untersuchungen wurden jedoch Abweichungen festgestellt, die mit der frequenz- und zeitvariablen Quellenstruktur zusammenhängen. Ein tieferes Verständnis der individuellen Positionsunterscheide der Quellen als auch der Unterschiede in der Orientierung der ICRFs mittels globaler systematischer Positionsunterschiede der Quellen kommt der großen Nutzergruppe von ICRF und Gaia zugute, wie z. B. der geodätischen VLBI für die Zusammenführung von VLBI-Produkten über Frequenzen hinweg. Diese Arbeit ergänzt die bestehenden Forschungsarbeiten über den Vergleich und die Orientierung der ICRFs um mehrere Fallstudien. Im optischen Frequenzbereich werden die ICRF3-Gegenstücke im Early Data Release 3 (Gaia EDR3, einschließlich Gaia-CRF3) der Gaia Raumsonde und im Gaia DR2, dem Vorgänger von Gaia EDR3, untersucht. Die Positionsunterschiede der einzelnen Gegenstücke für die verschiedenen Frequenzen werden neu bewertet, wobei der Schwerpunkt auf der Korrelation der normalisierten Entfernungen, der Richtungen der Positionsdifferenzen und der globalen systematischen Unterschiede mit der Anzahl der VLBI-Beobachtungen sowie dem Ausmaß der Radioquellenstruktur liegt. Die individuellen VLBI- und Gaia-Positionsunterschiede bevorzugen die selbe Richtung, insbesondere im Falle signifikanter Differenzen. Es wird gezeigt, dass große normalisierte Positionsunterschiede auf Quellen mit großer Radioquellenstruktur zurückzuführen sind. Die globalen systematischen Abweichungen, die um eine Größenordnung geringer sind als die individuellen Differenzen, können genau bestimmt werden. Dies gilt insbesondere wenn die Teilmenge der verwendeten Gegenstücke vorher definiert wurde. Ein Celestial Reference Frame (CRF), der aus S/X-Beobachtungen des selben Zeitintervalls wie Gaia DR2 ermittelt wurde, zeigt keine Verbesserungen in der Ausrichtung von Gaia DR2 im Vergleich zu ICRF3 S/X. Da die Orientierung von Gaia DR2 und Gaia EDR3 von der scheinbaren Helligkeit G ab- hängt und die Radioquellen des ICRF3 eine geringe scheinbare Helligkeit aufweisen, muss die Ausrichtung des hellen Anteils (G ≤ 13 mag) der Gaia-Daten auf den ICRF3 zusätzlich überprüft werden. In dieser Arbeit werden der Ansatz und die Daten von Lindegren (2020a) übernommen, der zur Überprüfung der Orientierung scheinbar helle Radiosterne verwendete. Da die Auflösung von VLBI und Gaia klein genug ist, um Eigenbewegungen von Sternen zu erkennen, müssen diese in den Orientierungstest einbezogen und auch eine zeitliche Variabilität der Orientierung geschätzt werden. Allerdings sind diese Ergebnisse bisher nicht genau genug im Vergleich zu den erwarteten Genauigkeiten der Astrometrie der einzelnen Quellen des hellen Anteils in der endgültigen Gaia-Datenveröffentlichung. In dieser Arbeit werden die vorhandenen VLBI-Daten der Radiosterne homogenisiert und es wird ein realistischeres Fehlerbudget für die VLBI-Positionen aufgestellt. Es wurden neue, gezielte VLBI-Beob-achtungen von hellen Radiosternen durchgeführt, um mehr dringend benötigte VLBI-Positionen für eine bessere Bestimmung der Orientierung zu erhalten. Die Positionen wurden auf zwei verschiedene Arten integriert: einmal als absolute Positionen aus einer Beobachtungsepoche und einmal als relative Positionen, um wann immer möglich neue präzise Modelle der Sternbewegung abzuleiten. Sowohl für Gaia DR2 als auch für Gaia EDR3 wurde eine signifikante zeitabhängige lineare Rotation um die Y -Achse ermittelt, wenngleich die Rotationen in dieser Richtung noch die geringste Genauigkeit aufweisen. Unter anderem werden die Genauigkeit der Ergebnisse, die Auswirkung der nichtlinearen Eigenbewegung und die Abhängigkeit von der scheinbaren Helligkeit innerhalb des hellen Anteils untersucht. Der Einfluss möglicher zukünftiger VLBI-Beobachtungen von Radiosternen auf die Orientierungsbestimmung wird getestet. Zusammenfassend evaluiert diese Arbeit die Genauigkeit der Orientierung der aktuellen ICRFs. Sie unterstreicht darüber hinaus die Notwendigkeit, VLBI-Beobachtungen von Radiosternen im Zusammenhang mit der Orientierung des hellen Gaia-Referenzrahmens zu ICRF3 genau zu prüfen, und zeigt, wie dies erreicht werden kann.

Description: Space geodetic techniques contribute significantly to enhancing our understanding of the Earth system. These techniques include Very Long Baseline Interferometry (VLBI), Global Navigation Satellite System (GNSS), Satellite Laser Ranging (SLR), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). The primary objective of these space geodetic techniques is to establish an accurate Terrestrial Reference Frame (TRF). Since each technique has its strengths and weaknesses, a combination of space geodetic techniques is employed to overcome the weaknesses in TRF determination. The current TRF, known as the International Terrestrial Reference Frame 2020 (ITRF2020), is determined with a combination of space geodetic techniques through station coordinate parameters at the co-location sites using local ties, which represent the difference between the station coordinates of a space geodetic technique at a co-location site. According to the scientific-driven requirements of the Global Geodetic Observing System (GGOS), the TRF needs to be established with an accuracy level of 1 mm. However, the ITRF2020 has not yet reached this scientific requirement. Therefore, another perspective needs to be investigated in order to reach the scientific-driven requirement for TRF determination. Microwave-based space geodetic techniques, such as VLBI and GNSS, observe under the same atmospheric conditions and are also included as a parameter in the adjustment process. Therefore, similar to station coordinates, this parameter can also be combined using ties. The ties for tropospheric parameters are referred to as "tropospheric ties". Unlike the local ties, which are directly measured using a total station or other distance measurements at the reference point of the space geodetic technique, tropospheric ties can only be derived through a model. Currently, two different approaches can be used to derive tropospheric ties. The first approach involves using an analytical model with meteorological data from different sources, such as meteorological sensors at the site, a Numerical Weather Model (NWM), and an empirical meteorological model. The second approach involves using the ray-tracing technique through a refraction field of NWM. However, since tropospheric ties can only be derived from the model, their accuracy is limited. To improve their accuracy, it is necessary to address the systematic effects that cause a discrepancy between the observed tropospheric parameter differences and tropospheric ties. This thesis investigates this discrepancy using the GNSS and VLBI intra/inter technique comparison of tropospheric parameters. The results indicate that the discrepancy is caused by the GNSS instrument, specifically the antenna and radome, in zenith total delay (ZTD) differences. On the other hand, the horizontal gradient difference is affected by multipath effects that occur at low-elevation observations, rather than the instrument. This study observes no systematic effect in VLBI due to the instrument. The systematic effect in tropospheric parameters due to the instrument is referred to as instrumental bias. To prove this hypothesis, a GNSS co-location site experiment was conducted. The experiment reveals that the instrumental bias in GNSS-derived ZTD parameters originates from the instrument. Furthermore, the bias in GNSS-derived horizontal gradients comes from the multipath effect that occurs at low-elevation observations. To address the instrumental bias, another GNSS co-location experiment was conducted. This experiment employed a vertical steering pole to minimize the height difference of various antenna phase centers to a few millimeters level during antenna changing. The experiment successfully kept the reference point position for each experiment antenna at the same position within a 2 mm level. Thus, the remaining bias in GNSS-derived tropospheric parameters is attributed to the instrumental bias. This study demonstrates the capability and limitations of tropospheric ties through a combination of VLBI and GNSS on the Normal Equation (NEQ) level. The combination of VLBI and GNSS with tropospheric ties shows a prominent improvement in station coordinates and tropospheric parameters. A VLBI intra-technique combination during CONT14 demonstrated improvements in station coordinates and tropospheric parameters for two telescopes at the Hobart co-location site. Tropospheric ties demonstrate a capability as alternative ties when the local ties are of poor quality, particularly the height component. The results indicate that VLBI received the most benefit when combining tropospheric parameters with tropospheric ties in both station coordinates and tropospheric parameters. The study of proper temporal resolution for applying tropospheric ties was investigated. The results show similar results for all scenarios in both station coordinates and troposphere parameters. For the first time, a combination of GNSS and VLBI utilizing tropospheric ties with an instrumental bias correction is performed. The results show a significant improvement in station coordinates, particularly in VLBI. Furthermore, applying tropospheric ties with an instrumental bias correction considerably reduces the discrepancy between local ties and the space geodetic technique solution. However, there is no improvement in tropospheric parameters from using instrumental bias correction for tropospheric ties. The study also evaluates the impact of weighting tropospheric ties. The results indicate that strong weight provides the most benefit from using tropospheric ties. Nevertheless, systematic effects must be addressed to avoid degradation in the combined solution. It is important to note that one full set of local ties, i.e., both horizontal and vertical components, is necessary to use tropospheric ties since they cannot fulfill rank deficiencies in the NEQ system.

Description: Die vier geodätischen Raumverfahren VLBI (Very Long Baseline Interferometry), GNSS (Global Navigation Satellite System), SLR (Satellite Laser Ranging) und DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) liefern Beiträge zum besseren Verständnis des Erdsystems. Ihre Datensätze sind von zentraler Bedeutung für die Realisierung eines präzisen terrestrischen Referenzrahmens (ITRF). Da die einzelnen Messtechniken Stärken und Schwächen für die TRF-Bestimmung aufweisen, werden die Datensätze kombiniert mit dem Ziel, die Schwächen auszugleichen. Der aktuelle ITRF, der Internationale Terrestrische Referenzrahmen 2020 (ITRF2020), ist eine Lösung, die kombinierte Stationskoordinaten an den Kollokationsstationen unter Verwendung lokaler Verbindungsvektoren (local ties), d.h. den Abstandsvektoren zwischen den jeweiligen Referenzpunkten, und kombinierte EOP (Erdorientierungsparameter) liefert. Das globale geodätische Beobachtungssystem (GGOS) stellt an die Lage des Ursprungs des ITRF die wissenschaftlich begründete Genauigkeitsanforderung von 1 mm. Die ITRF2020-Genauigkeit erfüllt diese Vorgabe jedoch nicht ganz. Um dieses Ziel zu erreichen, sind daher innovative Ansätze zu entwickeln. Die geodätischen Raumverfahren VLBI und GNSS, die Signale im Mikrowellenfrequenzspektrum nutzen, liefern an den Kolokationsstationen Beobachtungsdaten unter den gleichen atmosphärischen Bedingungen. Die Verknüpfung atmosphärischer Parameter kann daher ebenfalls im Ausgleichungsprozess eingesetzt werden. Ähnlich wie die Stationskoordinaten können diese Parameter auch miteinander verknüpft, also kombiniert, werden. Die Verknüpfung troposphärischer Parameter wird als „tropospheric tie“ bezeichnet. Im Gegensatz zu den lokal ties, die mit Totalstationen oder anderen Messgeräten am Referenzpunkt des jeweiligen Sensors gemessen werden, können die troposphärischen ties nur mittels Modellrechnungen bestimmt werden. Dabei werden gegenwärtig zwei verschiedene Ansätze verfolgt. Zum einen erfolgt die Berechnung mittels eines analytischen Modells auf der Grundlage meteorologischer Daten, die aus unterschiedlichen Quellen stammen, beispielsweise meteorologische Sensoren am Messstandort, numerische Wettermodelle (NWM) oder empirische meteorologische Modelle. Zum anderen wird die Methode der Strahlverfolgung (ray tracing) durch ein vom NWM abgeleitetes Brechungsindexfeld eingesetzt. Diese nur aus Modellen berechneten troposphärischen ties weisen notwendigerweise eine begrenzte Genauigkeit auf. Für höhere Genauigkeiten müssen weitere systematische Effekte berücksichtigt werden, die zu Abweichungen zwischen den beobachteten troposphärischen Parametern und den troposphärischen ties führen. Um diese systematischen Effekte zu untersuchen, werden in dieser Arbeit troposphärische Parameter verglichen, die in GNSS- und VLBI-Analysen berechnet wurden. Die Ergebnisse zeigen, dass signifikante Abweichungen in der vertikalen Signallaufzeitverzögerung (zenith total delay, ZTD) durch instrumentelle Effekte des GNSS-Verfahrensverursacht werden, insbesondere durch Elevations-abhängige Laufzeitvariationen und Verwendung einer Abdeckvorrichtung „radom“. Abweichungen der horizontalen Gradienten werden hingegen nicht durch das Instrument beeinflusst, sondern durch Mehrwegeffekte, die sich insbesondere auf Beobachtungen bei geringen Elevationswinkeln auswirken. In dieser Studie wird bei VLBI-Messungen kein systematischer Effekt, der instrumentelle Ursachen hat, beobachtet. Der systematische Effekt in den troposphärischen Parametern, der auf das Instrument zurückzuführen ist, wird im Folgenden als „instrumental bias“ bezeichnet. Für die Überprüfung der Hypothese, dass der instrumental bias überwiegend durch instrumentelle Effekte der von GNSS-Beobachtungen abgeleiteten ZTD-Parametern verursacht ist, wurde ein GNSS-Kollokationsexperiment durchgeführt. Die Ergebnisse des Experiments bestätigen diese Hypothese. Des Weiteren zeigt sich, dass der instrumental bias der horizontalen Gradienten, die von GNSS-Beobachtungen bei niedrigen Elevationen abgeleitet wurden, auf multi-pathing zurückzuführen ist. Um den instrumental bias in den ZTD-Parametern zu bestimmen, wurde ein weiteres GNSS-Kollokationsexperiment realisiert. Hierbei wurden Unterschiede in der Phasenzentrumsposition der verschiedenen Antennentypen mittels eines höhenverstellbaren Antennenmasts bis auf wenige Millimeter ausgeglichen. Während der Messung konnte die Position der Antennenreferenzpunkte erfolgreich innerhalb eines Bereichs von 2 mm gehalten werden. Die verbleibenden Abweichungen in den abgeleiteten troposphärischen Parametern sind daher nicht auf troposphärische Effekte sondern lediglich auf instrumentelle Ursachen zurückzuführen. Möglichkeiten und Grenzen der tropospheric ties werden in dieser Studie durch eine Kombination von VLBI- und GNSS-Beobachtungsdaten auf Normalgleichungsebene (NEQ) untersucht. Die Verwendung von tropospheric ties zeigt signifikante Effekte auf die Kombination von VLBI bzw. GNSS. Eine VLBI-Intratechnikkombination zweier Teleskope an der Kollokationsstation Hobart, Australien, während der CONT14-Messkampagne führt zu einer Genauigkeitssteigerung bezüglich der Stationskoordinaten und der troposphärischen Parameter. Die Untersuchung der tropospheric ties zeigt, dass sie eine Alternative zu den local ties darstellen, z.B. wenn diese fehlerbehaftet sind, insbesondere in der vertikalen Komponente. Die Ergebnisse zeigen, dass VLBI den größten Nutzen aus der Kombination von troposphärischen Parametern mit tropospheric ties zieht, sowohl bei den Stationskoordinaten als auch bei den troposphärischen Parametern. Es wird untersucht, welche zeitliche Auflösung für die Anwendung der tropospheric ties geeignet ist. Die Ergebnisse zeigen ähnliche Resultate für alle Szenarien, sowohl für Stationskoordinaten als auch für troposphärische Parameter. Zum ersten Mal wird eine Kombination von GNSS und VLBI unter Verwendung der tropospheric ties mit einer Korrektur des instrumental bias durchgeführt. Die Ergebnisse zeigen eine signifikante Verbesserung der Stationskoordinaten, insbesondere bei VLBI. Darüber hinaus wird durch die Anwendung der tropospheric ties mit der instrumental bias-Korrektur die Diskrepanz zwischen den local ties und den Ergebnissen aus den geodätischen Raumverfahren deutlich verringert. Bei den troposphärischen Parametern kann durch die Anwendung der instrumental bias-Korrektur jedoch keine Verbesserung nachgewiesen werden. Auch die Folgen der Gewichtung der tropospheric ties wird untersucht. Die Ergebnisse zeigen, dass sich eine hohe Gewichtung positiv auf die Verwendung der tropospheric ties auswirkt. Allerdings müssen systematische Effekte berücksichtigt werden, um eine Verschlechterung der kombinierten Lösung zu vermeiden. Es ist wichtig darauf hinzuweisen, dass für die Verwendung der tropospheric ties ein vollständiger Satz an local ties erforderlich ist, da die tropospheric ties nicht die Rangdefizite im NEQ-System ausgleichen können.

Description: BeiDou Navigation Satellite System (BDS), the Chinese component of Global Navigation Satellite Systems (GNSS), has come into operation and started to serve global users publicly since July 31st, 2020. BDS-3, i.e., the latest development of BDS, provides many services not only the traditional Position, Navigation and Timing (PNT) but also several featured ones such as Satellite-Based Augmentation Service (SBAS), Precision Point Positioning (PPP), Short Message Communication Service (SMCS) and Search And Rescue (SAR). Precise and accurate orbit and clock products are the perquisites of a GNSS to guarantee a high-quality service performance. BDS-3 is the first GNSS in which the Inter-Satellite-Link has been constellation-widely deployed. It has been preliminarily demonstrated that this new feature of BDS-3 improves the system’s survivability as well as its independence on the ground tracking. This study is devoted to the Precise Orbit Determination (POD) of BDS-3 with newly available ISL observations. The inherent incapability of ISL measurements of sensing the absolute variations of Right Ascension of the Ascending Nodes (RAANs) of satellite orbits hinders the autonomous orbit determination free from ground support. Different approaches to constrain the constellation rotation have been studied in the literature. On the other hand, orbit determination using only ISL observations can serve to evaluate the performance of the newly carried Inter-Satellite-Link payloads. Depending on the satellite, the post-fit RMS of ISL range observations is 4.2~10.5 cm. Eliminating the effects of constellation rotations, orbit precision based on ISL range observations is around 7.0, 4.6, and 3.5 cm in the along-track, cross-track, and radial direction, respectively. The clock observations of ISLs are used to synchronize the clocks of satellites within the constellation. The post-fit RMS of ISL clock observations ranges from ~2.9 cm to 10.0 cm, differing for satellites. For most satellites, similar precision of clock offsets as the IGS MGEX ACs’ products can be obtained by ISL measurements, with STDs around 0.15 ~ 0.20 ns. Hardware delays of Inter-Satellite-Links estimated from the range and clock observations both show very good temporal stability, with a monthly average STD of 0.13 and 0.08 ns, respectively. Harmonic signals taking the orbit motion as the fundamental frequency are found in both the range and clock residuals. Although it turns out those harmonic signals only affect the results marginally, a Fourier-like periodic function model is proposed to absorb them and has been proved effective. Several unresolved issues related to the POD of BDS-3 are investigated based on ground tracking data before studying the contributions of additional ISL observations. The effects of non-conservative perturbations from the Earth’s albedo and antenna thrust are significant and, therefore, need to be considered in the POD of BDS-3. The applicability of different empirical Solar Radiation Pressure (SRP) models and the necessity of an extra a-priori box-wing model are evaluated. Generally, the ECOM2 model shows superiority over the ECOM1 model as for BDS-3 satellites. And if the ECOM2 model is adopted,the additional a-priori box-wing model is unnecessary. In order to keep the backward compatibility of BDS-2, the strategy for integrated processing of BDS-2 and BDS-3, in which the legacy frequency combination B1I+B2I remains unchanged for BDS-2, is proposed and demonstrated. The contributions of incorporating ISL observations to the POD of BDS-3 are assessed comprehensively. First, the benefits of additional ISL range measurements are demonstrated in cases of different ground tracking networks. Secondly, the somehow unexpected improvement in the orbit precision brought by incorporating ISL clock observations is displayed. Furthermore, integratedly processing the ISL derived range, ISL derived clock, and L-band ground tracking observations reduces the orbit DBD by ~39% and 42% in the along-track and radial directions, respectively, compared to using only ground-tracking data. Last but not least, the contributions of ISL measurements to the estimation of geodetic parameters are proved, especially for the geocenter coordinates. Strong correlations between empirical SRP parameters and the geocenter Z-component, which plague the community for a long time, are significantly reduced by adding ISL observations. The results are very promising not just in terms of establishing and maintaining a national BDS-based terrestrial reference frame but also improving the potential contribution of BDS via the IGS community to the International Terrestrial Reference Frame (ITRF).

Description: Das BeiDou Navigation Satellite System (BDS), die chinesische Komponente von Global Navigation Satellite Systems (GNSS), ist seit dem 31. Juli 2020 in Betrieb und dient weltweit Benutzern öffentlich. BDS-3, dh die neueste Entwicklung von BDS, bietet viele Dienste, nicht nur die traditionelle Position, Navigation und Zeitmessung (PNT), sondern auch mehrere Funktionen wie der satellitengestützte Augmentation Service (SBAS), Precision Point Positioning (PPP), Short Message Communication Service (SMCS) und Search And Rescue (SAR). Präzise und genaue Orbit- und Clock-Produkte sind die Voraussetzungen für ein GNSS, um eine qualitativ hochwertige Serviceleistung zu gewährleisten. BDS-3 ist das erste GNSS, bei dem der Inter-Satellite-Link konstellationsweit eingesetzt wurde. Es wurde vorläufig gezeigt, dass diese neue Funktion von BDS-3 die Überlebensfähigkeit des Systems sowie seine Unabhängigkeit von der Bodenverfolgung verbessert. Diese Studie widmet sich der Precise Orbit Determination (POD) von BDS-3 mit neu verfügbaren ISL-Beobachtungen. Die inhärente Unfähigkeit von ISL-Messungen, die absoluten Variationen der Right Ascension of the Ascending Nodes (RAANs) von Satellitenumlaufbahnen zu erfassen, behindert die autonome Umlaufbahnbestimmung ohne Bodenunterstützung. In der Literatur wurden verschiedene Ansätze untersucht, um die Konstellationsrotation einzuschränken. Andererseits kann die Bestimmung der Umlaufbahn, die nur ISL-Beobachtungen verwendet, dazu dienen, die Leistung der neu beförderten InterSatellite-Link-Nutzlasten zu bewerten. Abhängig vom Satelliten beträgt der Post-Fit-RMS der ISLBereichsbeobachtungen 4,2 bis 10,5 cm. Unter Eliminierung der Auswirkungen von Konstellationsrotationen beträgt die Orbit-Präzision basierend auf ISL-Entfernungsbeobachtungen etwa 7,0, 4,6 bzw. 3,5 cm in Längs-, Quer- und Radialrichtung. Die Uhrenbeobachtungen von ISLs werden verwendet, um die Uhren von Satelliten innerhalb der Konstellation zu synchronisieren. Der Post-Fit-RMS von ISL-Uhrbeobachtungen reicht von ~2,9 cm bis 10,0 cm, unterschiedlich für Satelliten. Bei den meisten Satelliten kann durch ISL-Messungen eine ähnliche Genauigkeit der Taktverschiebungen wie bei den Produkten der IGS MGEX ACs mit STDs von etwa 0,15 bis 0,20 ns erreicht werden. Hardwareverzögerungen von Inter-Satellite-Links, die aus den Entfernungs- und Taktbeobachtungen geschätzt wurden, zeigen beide eine sehr gute zeitliche Stabilität mit einer monatlichen durchschnittlichen STD von 0,13 bzw. 0,08 ns. Harmonische Signale, die die Bahnbewegung als Grundfrequenz nehmen, werden sowohl in den Entfernungs- als auch in den Taktresten gefunden. Obwohl sich herausstellt, dass diese harmonischen Signale die Ergebnisse nur marginal beeinflussen, wird ein Fourier-ähnliches periodisches Funktionsmodell vorgeschlagen, um sie zu absorbieren und sich als effektiv erwiesen hat. Mehrere ungelöste Probleme im Zusammenhang mit dem POD von BDS-3 werden auf der Grundlage von Bodenverfolgungsdaten untersucht, bevor die Beiträge zusätzlicher ISL-Beobachtungen untersuchtwerden. Die Auswirkungen nicht-konservativer Störungen durch die Albedo der Erde und den Antennenschub sind signifikant und müssen daher im POD von BDS-3 berücksichtigt werden. Die Anwendbarkeit verschiedener empirischer Solar Radiation Pressure (SRP)-Modelle und die Notwendigkeit eines zusätzlichen a-priori-Box-Wing-Modells werden evaluiert. Im Allgemeinen zeigt das ECOM2- Modell eine Überlegenheit gegenüber dem ECOM1-Modell für BDS-3-Satelliten. Und wenn das ECOM2- Modell übernommen wird, ist das zusätzliche A-priori-Box-Wing-Modell überflüssig. Um die Abwärtskompatibilität von BDS-2 zu erhalten, wird die Strategie zur integrierten Verarbeitung von BDS- 2 und BDS-3 vorgeschlagen und demonstriert, bei der die Legacy-Frequenzkombination B1I+B2I für BDS-2 unverändert bleibt. Die Beiträge der Einbeziehung von ISL-Beobachtungen in den POD von BDS-3 werden umfassend bewertet. Zunächst werden die Vorteile zusätzlicher ISL-Entfernungsmessungen bei unterschiedlichen Bodenverfolgungsnetzwerken demonstriert. Zweitens wird die irgendwie unerwartete Verbesserung der Bahngenauigkeit durch die Einbeziehung von ISL-Uhrenbeobachtungen angezeigt. Darüber hinaus reduziert die integrierte Verarbeitung der ISL-abgeleiteten Entfernung, des ISL-abgeleiteten Takts und der L-Band-Bodenverfolgungsbeobachtungen die Bahn-DBD um ~39 % bzw . Nicht zuletzt werden die Beiträge von ISL-Messungen zur Schätzung geodätischer Parameter, insbesondere für die Geozentrumskoordinaten, nachgewiesen. Starke Korrelationen zwischen empirischen SRP-Parametern und der Geozentrum-Z-Komponente, die die Community schon lange plagen, werden durch das Hinzufügen von ISL-Beobachtungen deutlich reduziert. Die Ergebnisse sind nicht nur im Hinblick auf die Einrichtung und Aufrechterhaltung eines nationalen BDS-basierten terrestrischen Referenzrahmens sehr vielversprechend, sondern auch hinsichtlich der Verbesserung des potenziellen Beitrags von BDS über die IGS-Community zum International Terrestrial Reference Frame (ITRF).

Description: Presented are analytical data from lacustrine sediment cores, retrieved from Lake Nam Co (Tibetan Plateau). The sediment core is a composite of one gravity core, taken with a Rumohr-Meischner gravity corer (63 mm diameter) and a piston core, retrieved using an uwitec piston coring system (http://www.uwitec.at; 90 mm diameter). The composite core labelled 〈NC 08/01〉 comprises a total length of 10.378 m. The cores were obtained at N 30.737417, E 090.790333 at a water depth of 93 m on 2008-09-15. The purpose of obtaining this sediment core was to establish a high-resolution record of climate (monsoonal) and environmental change using multiple proxy data. The dataset comprises analytical data based on sedimentological, inorganic geochemical, mineralogical and isotope-geochemical methods. Specifically: sediment water content & density; magnetic susceptibility; particel size data; quantitative inorganic geochemical data (ICP-OES aqua regia and HCL digestions); semi-quantitative XRF elemental data; carbon, nitrogen, sulfur contents; qualitative mineralogical data; bulk sediment stable carbon and oxygen isotope data.

Description: This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized X-ray fluorescence line scanning (XRF)-based element data of sediment core EN18208, retrieved in 2018 from Lake Ilirney (Chukotka, Russia) at 10.76 m water depth. The glacial lake Ilirney is situated in the forest tundra mountain area and has one outflow, one main inflow and several smaller inflows. It lies at an elevation of ca. 428 m a.s.l. with a surface area of ca. 30 km2 and a maximum lake water depth of estimated 44 m. The 10.76 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2018_Chukotka expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). The downcore elemental composition was measured using an AVAATECH x-ray fluorescence core scanner at Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) in Berlin, Spandau.

Description: This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized radiocarbon and OSL age data of sediment core EN18208, retrieved in 2018 from Lake Ilirney (Chukotka, Russia) at 10.76 m water depth. The glacial lake Ilirney is situated in the forest tundra mountain area and has one outflow, one main inflow and several smaller inflows. It lies at an elevation of ca. 428 m a.s.l. with a surface area of ca. 30 km2 and a maximum lake water depth of estimated 44 m. The 10.76 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2018_Chukotka expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Radiocarbon data have been analysed from bulk sediment samples in Bremerhaven at the MICADAS laboratory. Optically stimulated luminescence (OSL) dating was performed at the Royal Holloway Luminescence Laboratory using a Risø TL/OSL-DA-15 automated dating system.

Description: A 25-cm long predominantly aragonite stalagmite was collected November 2, 2005 from Dharamjali Cave (29.5°N, 80.2°E) in the central Himalayas. This dataset contains stable isotope, trace element, XRF, U/Th dating, and dripwater data. The age model spans 4.2 to 2.3 ka BP, and the dataset records seasonal shifts in hydroclimate from 4.2 to 3.1 ka BP. Using the DHAR-1A half of the speleothem, 750 samples were milled at 100–300 µm resolution for stable isotope analysis (δ18O and δ13C) and analyzed at GFZ Potsdam. Further high-resolution stable isotope analysis at the University of Cambridge included 876 samples from the bottom 4 cm of the mirroring slab DHAR-1B, covering c. 4.2–3.6 ka BP. The δ44/40Ca measurements were made on 60 aragonite samples of aragonite and 1 calcite sample milled between 4.2 and 2.8 ka BP. The elemental composition of DHAR-1B was determined first with an Avaatech XRF scanner at the University of Cambridge, and later using laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) at the University of Waikato. U-series dating was performed at Caltech on 22 samples. Twelve U-series ages (between 2.55 and 4.14 ka BP) were used to construct the age models, using ensembles of 2000 Monte Carlo simulations for each proxy using the MATLAB-based COPRA script (Breitenbach et al., 2012, https://doi.org/10.5194/cp-8-1765-2012).

Description: This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized grain size element data of sediment core EN18208, retrieved in 2018 from Lake Ilirney (Chukotka, Russia) at 10.76 m water depth. The glacial lake Ilirney is situated in the forest tundra mountain area and has one outflow, one main inflow and several smaller inflows. It lies at an elevation of ca. 428 m a.s.l. with a surface area of ca. 30 km2 and a maximum lake water depth of estimated 44 m. The 10.76 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2018_Chukotka expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Grain-size was measured using a Malvern Mastersizer 3000 laser diffraction particle analyser.

Description: This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized mineral data of sediment core EN18208, retrieved in 2018 from Lake Ilirney (Chukotka, Russia) at 10.76 m water depth. The glacial lake Ilirney is situated in the forest tundra mountain area and has one outflow, one main inflow and several smaller inflows. It lies at an elevation of ca. 428 m a.s.l. with a surface area of ca. 30 km2 and a maximum lake water depth of estimated 44 m. The 10.76 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2018_Chukotka expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Bulk mineralogy was analysed by (x-ray diffractometry (XRD) using a (PHILIPS, Netherlands) PW1820 goniometer.

Description: This data set is part of a larger data harmonization effort to make lake sediment core data machine readable and comparable. Here we standardized radiocarbon and OSL age data of sediment core EN18208, retrieved in 2018 from Lake Ilirney (Chukotka, Russia) at 10.76 m water depth. The glacial lake Ilirney is situated in the forest tundra mountain area and has one outflow, one main inflow and several smaller inflows. It lies at an elevation of ca. 428 m a.s.l. with a surface area of ca. 30 km2 and a maximum lake water depth of estimated 44 m. The 10.76 m sediment core was retrieved by a UWITEC piston corer during the RU-Land_2018_Chukotka expedition of the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI, Germany, Potsdam) in cooperation with the North Eastern Federal State University (NEFU, Russia, Yakutsk). Water content and organic matter was analysed at AWI Potsdam. Dried and milled samples were analysed using a Vario EL III carbon-nitrogen-sulphur analyser. Organic carbon content was determined using a Vario MAX C analyser.

Description: The recent deliverable describes the development and the characteristics of the European Fluid Atlas (EFA) created in the frame of the REFLECT project by University of Miskolc. In the Atlas, formerly existing and newly measured data of geothermal fluids are visualised. Fluid data were collected from 21 European countries. The layers provide point feature information presented on a base map, including geography, geology, and depth range, as well as physical, chemical and microbial properties of fluids. Data of wells, rocks and reservoirs are also available. The focus is on fluids used for electricity generation (〉 100 °C), but data from heat projects are also included. A free and open-source cross-platform is used for the visualisation, in which the geographic information system provides the environment to view, edit and analyse geospatial data. The interface includes query and filtering tools to explore the database with a map-based visualization. The query results can be downloaded as an excel worksheet. By selecting the entire dataset, the downloaded report contains all the data published on EFA.

Description: Despite the importance of surface energy budgets (SEBs) for land-climate interactions in the Arctic, uncertainties in their prediction persist. In situ observational data of SEB components - useful for research and model validation - are collected at relatively few sites across the terrestrial Arctic, and not all available datasets are readily interoperable. Furthermore, the terrestrial Arctic consists of a diversity of vegetation types, which are generally not well represented in land surface schemes of current Earth system models. This dataset describes the data generated in a literature synthesis, covering 358 study sites on vegetation or glacier (〉=60°N latitude), which contained surface energy budget observations. The literature synthesis comprised 148 publications searched on the ISI Web of Science Core Collection.

Description: Deliverable D2.4 reports on the activities performed within Task 2.4 “Thermophysical properties of geothermal fluids” until the end of month 36 of the REFLECT project. The task breaks down into three subtasks of different scope: Task 2.4.1 - In situ measurements of fluid thermophysical properties, Task 2.4.2 - Thermoelectrical properties, and Task 2.4.3 - Modelling of density and heat capacity. Overall, a better understanding of the thermophysical properties of highly saline geothermal fluids was obtained by a combination of analytical data evaluation, improvement of measurement devices, laboratory measurements and numerical modelling.

Description: This report summarises the webinars organised in the REFLECT project between 2021 and 2022, in the framework of the WP6 Dissemination and exploitation, Task 6.2 – Ensure transferability and exploitation of project results. The Task 6.2 planned to inform the stakeholders identified in the matrix developed under Task 6.1 about the project activities and main outcomes. For this purpose, periodic webinars have been organised between 2021 and 2022 presenting these results and information.

Description: This report presents the stakeholder workshops organised in the REFLECT project, in the framework of the WP6 Dissemination and exploitation, Task 6.2 – Ensure transferability and exploitation of project results. The Task 6.2 planned to inform the stakeholders identified in the matrix developed under Task 6.1 about the project activities and main outcomes. For this purpose, two physical stakeholder workshops were organised during the project. The first workshop, at the start of the project, was dedicated to a first communication of the project’s objectives and expected outcomes. It also had the aim to receive feedback from geothermal operators on their most significant operational problems related to geothermal fluid properties. This first workshop was, therefore, limited to the Advisory Board members in order to build on their specific experience. The second stakeholder workshop presented the project’s results most relevant to geothermal operators or service companies/consultants. The objective of the second stakeholder workshop was to share projects results with a broad group of stakeholders. Therefore, it was widely promoted and the registration was open to all and free of charge. Both workshops received positive feedback from stakeholders and project partners.

Description: Global growth of industry and population leads to increasing demand of industrial and consumer goods. This necessitates an increase in mining activities and resource extraction. Resulting mine waste, and tailings serve as a repository for unused overburden and for the accumulation of processed waste-products. It is typical for so-called secondary iron minerals (SIMs) to be formed during the weathering of these materials under different pH-value conditions. Acid mine drainage (AMD) can result from rainwater infiltration and chemical processes within the deposited mass. Therefore, mine tailings must be spatially separated from their surroundings and monitored. The emergence of remote sensing methods provides new opportunities to survey large areas. In this work a remote sensing approach was used to discriminate SIMs from surrounding material and minerals and subsequently classify different SIMs on the surface. This allows to reconstruct (/comprehend the former) the acidic environments that prevailed during the formation of these minerals and gives indication of the occurrence of AMD. Various SIMs have pH-values ranging from strongly acidic (〈1.5, i.e., Schwertmannite and Copiapite) to neutral (〉7, i.e., Hematite). Classifying these SIMs, leads to the identification of contaminated areas. This method was developed based on a laboratory dataset with different minerals and vegetation samples. The datasets were originally acquired with hyperspectral HySpex cameras in the laboratory and were resampled to WorldView-3 (WV3) and Sentinel-2 (S2) band characteristics for analysis. A combination of different filter methods made pixel-based separation of SIMs possible. The results were subsequently classified using a RF-model to distinguish between different SIMs. In this training dataset, the RF model achieved an overall accuracy of 94.44% for the WV3 and S2 datasets (the area-adjusted overall accuracy was 93.45% and 93.62%, respectively). Subsequently, a second laboratory dataset with field samples was analysed using the same technique and the classification results were compared with XRD analyses of the samples. Satellite images from WV3 and S2 sensors were then analysed using this methodology. The results for the study area of volcanogenic massive sulphide deposits in the Republic of Cyprus, namely Skouriotissa and Apliki, were then compared. The results for the Skouriotissa mine region showed a potential area of 17.22 to 45.58 ha of strongly acidic environment (by classification of Jarosite, pH~2.4) and 8.86 to 26 ha of moderately acidic environment/ contamination (by classification of Goethite/Limonite, pH~5) based on the WV3 satellite image. 27.32 to 87.04 ha and 6.12 to 38.24 ha for the S2 image, respectively.

Description: Das Wachstum von Industrie und Bevölkerungszahl weltweit sowie technologische Fortschritte und Entwicklungen führen zu einer steigenden Nachfrage von Industrie- und Konsumgütern. Als Folge entstehen eine erhöhte Rohstoffnachfrage und ein Ausbau der Ressourcengewinnung sowie des Bergbaus. Abfallprodukte des Bergbaus und nicht genutztes Material (Abraum) werden meist in oder um den Abbaustandort aufgeschüttet. Diese sind natürlichen Degradationsprozessen ausgesetzt, bei denen saure Abwässer entstehen können. Dies geschieht durch die Verwitterung des Pyrit Minerals infolge der Infiltration von Regenwasser durch das Material. In unterschiedlichen pH-Wertumgebungen bilden sich unterschiedliche Minerale aus. Typisch sind die sogenannten sekundären Eisenminerale (SIMs – secondary iron minerals). Ein Auftreten dieser kann daher zu einer pH-Wert Abschätzung genutzt werden und mögliche saure Grubenwässer aufzeigen. Fernerkundungsmethoden bieten die Möglichkeit große Areale oberflächlich zu erfassen und abzubilden, was zu einer weitreichenden Überwachung genutzt werden kann. In dieser Arbeit wurde eine Methode auf Grundlage von multispektralen Fernerkundungsdaten (Satellitenbilder von WorldView-3 und Sentinel-2) entwickelt, welche sekundäre Eisenminerale identifiziert und klassifiziert. Die Identifikation wurde durch den Einsatz von Masken erreicht. So fand eine Unterscheidung zwischen Pixeln statt, die und die keine typische spektrale Signale von SIMs aufweisen. Die Klassifikation wurde mit Hilfe eines RF-Modells durchgeführt. Dieses wurde anhand synthetischer Labordatensätze entwickelt und validiert. Im Trainingsdatensatz erreichte das RF-Modell eine Gesamtgenauigkeit von 94,44 % für die WorldView-3 und Sentinel-2 Datensätze. Es wurden drei Klassen mit verschiedenen pH-Wert-Identifikationen unterschieden: Hämatit (pH〉7), Goethit/ Limonit (pH~5) und Jarosit (pH~2.4). Die Methodik wurde anschließend auf Satellitenbilder aus der Republik Zypern angewendet. Dabei standen die Minengebiete Skouriotissa und Apliki im Fokus, welche zu den vulkanogenen Massivsulfid-Lagerstätten (VMS-type) zählen. Die Ergebnisse für das Skouriotissa-Minengebiet ergaben auf der Grundlage des WV3-Satellitenbildes eine potenzielle Fläche von 17,22 bis 45,58 ha in stark saurem Milieu (Jarosit) und 8,86 bis 26 ha in mäßig saurem Milieu (Goethit/ Limonit) bzw. 27,32 bis 87,04 ha und 6,12 bis 38,24 ha für das Sentinel-2 Satellitenbild.

Description: The evaluation of the effect of organic compounds and microorganisms in formation and precipitation of colloids using artificial brines was performed by TNO using selected organic compounds based on the analysis of sampled fluids corresponding to the information gathered on the sites by GFZ. The same was done with biofilms prepared with microorganisms (Thermaerobacter sp., Penicilium citrinum) isolated from geothermal stations by UNINE. All carboxylic acids tested had an inhibiting effect on the precipitation of calcium carbonate. The biofilm components seem to develop intense interaction with the ions, nuclei and/or crystals formed during the executed experiments. In the presence of biofilms, the transformation of the intrinsically formed vaterite morphology to equilibrium calcite morphologies is delayed or hindered and scaling was inhibited.

Description: This Technical Report presents data from a solaroptical spectral investigation in the area of the Rammelsberg non-ferrous metal mine in the Harz Mountains near the city of Goslar. The investigation refers to the local communion stone quarry (“Kommunionssteinbruch”) above the former mining area. As this is a nature conservation zone, all measurements were carried out in-situ without any physical sampling action. The field measurements were carried out in June 2019 in cooperation with Bergbau Goslar GmbH and the German Research Centre for Geosciences (GFZ). The data were collected within the research project ReMon (Remote Monitoring of Tailings Using Satellites and Drones, https://www.gfzpotsdam. de/en/section/remote-sensing-and-geoinformatics/projects/remon/) which aims at developing a prototypical monitoring system for mine tailings by using different sensors scaling from satellite- to drone-based. The data were analysed in the unpublished B.Sc. thesis of Constantin Hildebrand (Hildebrand, 2019). Sixteen different surface materials were determined and examined on-site. Point and imaging hyperspectral data were acquired (with the spectroradiometer PSR+ 3500 operating in the range of 350 - 2500 nm and with the Cubert FireflEYEUHD-185 hyperspectral camera with a range of 450 - 950 nm, respectively), both data sets are presented as spectral libraries. Chemical analyses of the samples were performed by using Laser-Induced Breakdown Spectroscopy (LIBS). LIBS data were collected using a handheld LIBS analyzer, the SciAps Z-300. In this report the different in-situ measurements are presented for each of the sixteen samples. Detailed information about the analysed material, the area of spectral sampling and geochemical analyses are explained in this report and can also be found in the additional Excel® sheet provided with the data.

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Description: This document is a collection of the REFLECT factsheets produced for promoting the project results.

Description: This deliverable summarizes the activities related to the development of predictive models to simulate the impact of fluid flow hydrodynamics and chemical composition uncertainties on the production behavior of geothermal assets. Specifically, in this report, the mineral precipitation behavior of the geothermal fluid was studied as both uncertainties in the fluid composition and the interaction between the fluid flow hydrodynamics and mineral precipitation can impact the deposition of the scaling. A workflow was developed to couple a multiphase flow solver to thermodynamics libraries and models which are used to simulate the precipitation amount and kinetics of different geothermal minerals. This coupled workflow will enable a better estimation of the location and amount of precipitated minerals in different location of a geothermal system. A detailed roughness model was developed to simulate the impact of mineral deposition to the fluid flow. In addition, an uncertainty quantification workflow was combined with the modelling framework to estimate the uncertainty bounds of the scaling and precipitation resulted from uncertainties in the fluid composition characterization and operational settings. The modelling and uncertainty quantification workflow was demonstrated on a barite precipitation case study in a heat exchanger. Initially, the impact of geo-chemical uncertainties (in fluid composition) on the mineral precipitation was assessed. Afterwards, the coupled fluid flow and precipitation model with the developed roughness model was tested. Finally, the coupled uncertainty quantification workflow with the coupled model was simulated to assess the impact of fluid composition uncertainties on mineral deposition. As an outcome of the simulation, the impact of uncertainties in the mineral deposition on reduction in the production rate and heat transfer (within the heat exchanger) was calculated. The developed framework is flexible and generic which can be applied to various production and operational challenges in geothermal assets. In the future, the workflow can be used to optimize the design and operation of geothermal assets considering various sources of uncertainties which is not only fluid composition but also operational conditions (link to D4.5 REFLECT), robust modelling of other geo-chemical and flow assurance challenges in geothermal sites or even developing geo-chemical risk maps for different sites within EU (link to WP3 REFLECT).

Description: The rewetting of peatlands is a promising measure to mitigate greenhouse gas (GHG) emissions by preventing the further mineralization of the peat soil through aeration. In coastal peatland, the rewetting with brackish water can increase the GHG mitigation potential by the introduction of sulfate, a terminal electron acceptor (TEA). Sulfate is known to lower the CH4 production and thus, its emission by favoring the growth of sulfate-reducers, which outcompete methanogens for substrate. The data contain porewater variables such as pH, electrical conductivity (EC) and sulfate, chloride, dissolved CO2 and CH4 concentrations, as well as absolute abundances of methane- and sulfate-cycling microbial communities. The data were collected in spring and autumn 2019 after a storm surge with brackish water inflow in January 2019. Field sampling was conducted in the nature reserve Heiligensee and Hütelmoor in North-East Germany, close to the Southern Baltic Sea coast. We took peat cores using a Russian peat corer in addition to pore water diffusion samplers and plastic liners (length: 60cm; inner diameter 10 cm) at four locations along a transect from further inland towards the Baltic Sea. We wanted to compare the soil and pore water geochemistry as well as the microbial communities after the brackish water inflow to the common freshwater rewetting state. Pore water was extracted using pore water suction samplers in the lab and environmental variables were quantified with an ICP. Microbial samples were sampled from the peat core using sterile equipment. We used quantitative polymerase chain reaction (qPCR) to characterize pools of DNA and cDNA targeting total and putatively active bacteria and archaea. qPCR was performed on key functional genes of methane production (mcrA), aerobic methane oxidation (pmoA) and sulfate reduction (dsrB) in addition to the 16S rRNA gene for the absolute abundance of total prokaryotes. Furthermore, we retrieved soil plugs to determine the concentrations and isotopic signatures of dissolved trace gases (CO2/DIC and CH4) in the pore water.

Description: This dataset provides annually resolved microfacies data from ICDP core 5017-1-A, retrieved from the deep northern Dead Sea basin in 2010/11, for the last glacial-interglacial transition (ca. 14-13 ka BP). Sediments of the Lisan Formation were investigated between ~94.7 and 91.8 m sediment depth below lake floor (lithozone C2) by continuous thin section microscopy. Thin sections were prepared following the standard procedure by Brauer and Casanova (2001) that was adjusted for salty sediments. Thin section analyses were performed on overlapping large-scale thin sections using a Zeiss Axiolab pol microscope at magnifications of 50-400x. Microfacies analyses included varve counting and measurements of varve and sublayer thickness. The amount of varves in erosional gaps was interpolated and the position of mass flow deposits (MFD) is marked.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: These datasets describe sediment samples taken from the Batagay megaslump, located in Yana Uplands in northeastern Siberia. Most sediment samples were taken from the slump headwall (B19-P1) by rapelling down on a rope from the slump surface and taking samples with a hole saw (diameter 55 mm, 40 mm deep) mounted on a handheld power drill. A second profile (B19-02) of the lowest part of the slump headwall was sampled (~100 m south) using a hammer and axe from the slump floor. Two permafrost sediment blocks (B19-03 and B19-04) at the slump bottom that had fallen from the headwall were sampled using a chainsaw. Finally, a baidzherakh (thermokarst mound; B19-05) in the north of the slump was sampled using a hammer and axe. The samples cover 5 stratigraphical units: 1. lower ice complex, 2. lower sand unit, 3. woody layer, 4. upper ice complex, 5. Holocene cover.

Description: Organic carbon (OC) stored in Arctic permafrost represents one of Earth’s largest and most vulnerable terrestrial carbon pools. Amplified climate warming across the Arctic results in widespread permafrost thaw. Permafrost deposits exposed at river cliffs and coasts are particularly susceptible to thawing processes. Accelerating erosion of terrestrial permafrost along shorelines leads to increased transfer of organic matter (OM) to nearshore waters. However, the amount of terrestrial permafrost carbon and nitrogen as well as the OM quality in these deposits are still poorly quantified. Here, we characterise the sources and the quality of OM supplied to the Lena River at a rapidly eroding permafrost river shoreline cliff in the eastern part of the delta (Sobo-Sise Island). Our multi-proxy approach captures bulk elemental, molecular geochemical and carbon isotopic analyses of late Pleistocene Yedoma permafrost and Holocene cover deposits, discontinuously spanning the last ~52 ka. We show that the ancient permafrost exposed in the Sobo-Sise cliff has a high organic carbon content (mean of about 5 wt%).We found that the OM quality, which we define as the intrinsic potential to further transformation, decomposition, and mineralization, is also high as inferred by the lipid biomarker inventory. The oldest sediments stem from Marine Isotope Stage (MIS) 3 interstadial deposits (dated to 52 to 28 cal kyr BP) and is overlaid by Last Glacial MIS 2 (dated to 28 to 15 cal ka BP) and Holocene MIS 1 (dated to 7–0 cal ka BP) deposits. The relatively high average chain length (ACL) index of n-alkanes along the cliff profile indicates a predominant contribution of vascular plants to the OM composition. The elevated ratio of iso and anteiso-branched FAs relative to long chain (C ≥ 20) n-FAs in the interstadial MIS 3 and the interglacial MIS 1 deposits, suggests stronger microbial activity and consequently higher input of bacterial biomass during these climatically warmer periods. The overall high carbon preference index (CPI) and higher plant fatty acid (HPFA) values as well as high C / N ratios point to a good quality of the preserved OM and thus to a high potential of the OM for decomposition upon thaw. A decrease of HPFA values downwards along the profile probably indicates a relatively stronger OM decomposition in the oldest (MIS 3) deposits of the cliff.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Rock magnetic and paleomagnetic results covering the past 30 ka were constructed from two sediment cores MSM33_856-1 (MSM33-55-1) and MSM33_855-1 (54-3) from the Black Sea. After the Mediterranean Sea water ingression, finely laminated organic-rich sapropelic sediments and coccolith oozes were deposited in the Black Sea since about 8.3 ka. Relict magnetic minerals in the Black Sea sarpoples are ferrous hemoilmenite, Fe-Mn and Fe-Cr spinels, and magnetite inclusions. In sediments deposited between about 14 and 8 ka, greigite and pyrite were formed in sediments because of the seawater penetration from overlying sediments after the seawater ingression. Before ~14 ka, the Black Sea sediments are dominated by detrital (titano-)magnetite minerals and the sporadically formed greigite which has SIRM/kLF ratios 〉 10 kAm-2. By comparison with detrital (titano-)magnetite samples between 20-30 ka, we found that relict magnetic mineral samples between 0-8.3 ka have similar behavior in recording the geomagnetic field. Moreover, the geomagnetic field variations reconstructed from the Black Sea sapropels are comparable with other validated regional datasets for the past 8.3 ka. The natural remanent magnetization (NRM) and the anhysteretic remanent magnetization (ARM) were measured with a 2G Enterprises 755 SRM (cryogenic) long-core magnetometer equipped with a sample holder for eight discrete samples at a separation of 20 cm. The magnetometer's in-line tri-axial alternating field (AF) demagnetizer was used to demagnetize the NRM and ARM of the samples. The NRM was measured after application of AF peak amplitudes of 0, 5, 10, 15, 20, 30, 40, 50, 65, 80, and 100 mT. Directions of the characteristic remanent magnetization (ChRM) were determined by principle component analysis (PCA) according to Kirschvink (1980). The error range of the ChRM is given as the maximum angular deviation (MAD). The ARM was imparted along the samples' z-axis with a static field of 0.05 mT and an AF field of 100 mT. Demagnetization then was performed in steps of 0, 10, 20, 30, 40, 50, 65, and 80 mT. The median destructive field of the ARM (MDFARM) was determined to estimate the coercivity of the sediments. The slope of NRM versus ARM of common demagnetization steps was used to determine the relative paleointensity (RPI). In most cases, demagnetization steps from 20 to 65 mT were used to determine the RPI.

Description: This dataset provides data for four third-degree tidal constituents used in the publication of Sulzbach et al (2022). The tidal constituents provided are the 3M1, 3M3, 3N2 and 3L2 for 134 globally distributed stations. The tide information, such as the nodal modulations of these tides, are taken from Table 1 and Table S2 of Ray (2020). These tidal constants are estimated using the GESLA dataset (Woodworth et al 2014) following the approach presented in Piccioni et al (2019). This record is an add-on to the full TICON dataset (https://doi.org/10.1594/PANGAEA.896587), using exactly the same data format and pre-processing. These steps include using tide gauge data that contains at least ten years of continuous data. Further, the dataset is restricted to only contain open ocean tide gauges by limiting it to a mean surrounding depth of tide gauges to be deeper than 500 meters in a 2-degree radius and excluding stations not native to the ocean domain of the employed tidal model TiME. Duplicate and closely neighbouring tide gauges, found within a 0.2-degree radius, are also removed from the dataset. This resulted in the availability of the four tidal constants for 134 tide gauges. The results are stored in one tab-separated text/ASCII file with 13 columns: 1. Latitude of the tide gauge station 2. Longitude of the tide gauge station 3. Constituent name 4. Amplitude (in cm) 5. Phase (in degrees) 6. Standard deviation of the amplitude (in cm) 7. Standard deviation of the phase (in degrees) 8. Percentage of missing observations 9. Total number of observations analyzed 10. Length of the maximum temporal gap found in the time series in days 11. Date of the first observation 12. Date of the last observation 13. Code that corresponds to the original source of the record TICON is a useful and easy-to-handle data set for tide model validation and allows the users to select the records according to the different criteria most suitable for their purposes. The options span from the choice of a geographical region to the use of single constituents or time periods.

Description: These datasets provide sedimentological data partly at annual resolution and an age model for the lateglacial part of (1) the ICDP sediment core 5017-1-A retrieved from the deep northern Dead Sea basin in 2010/11, and (2) for the Masada outcrop located at the southwestern shore of the Dead Sea sampled in 2018. The here investigated two sediment sections cover the last glacial-interglacial transition (ca. 17-11.5 ka BP) in the hydroclimatically sensitive Levant, when the water level of Lake Lisan – the precursor of the Dead Sea – dropped dramatically from its glacial high-stand to the Holocene low levels. Here, we analyze the interval between the last two gypsum units – the Upper Gypsum Unit (UGU) and the Additional Gypsum Unit (AGU) – which were also used to correlate the two sites. In the ICDP core this section is located between ~101 and 88.5 m sediment depth below lake floor and at Masada it encompasses the uppermost ~3.8 m sediments of the Lisan Formation, which form the terminal deposit at this site. Due to the lake level decline, the complete transition into the Holocene is only recorded in the ICDP core, while sedimentation at Masada terminates earlier. The microfacies was investigated by continuous thin section microscopy, while additional macroscopic information is provided from over- and underlying sediment sections. A revised chronology using age modelling in OxCal (Ramsey 2008; Ramsey 2009; Ramsey and Lee 2013) was developed for the ICDP core and a floating varve chronology was constructed at Masada. Using these new microfacies data from marginal (Masada) and deep-water (ICDP core) sediments, the hydroclimatic variability during the final stage of Lake Lisan can be reconstructed, which could provide important insights into the development of human sedentism in the region at this time.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: This dataset provides annually resolved microfacies data from ICDP core 5017-1-A, retrieved from the deep northern Dead Sea basin in 2010/11, for the last glacial-interglacial transition (ca. 17-11.5 ka BP). Sediments of the Lisan Formation were investigated between ~101 and 88.5 m sediment depth below lake floor by continuous thin section microscopy, while additional macroscopic information is provided from core catchers, as well as from over- and underlying sediment sections. Thin sections were prepared following the standard procedure by Brauer and Casanova (2001) that was adjusted for salty sediments. Thin section analyses were performed on overlapping large-scale thin sections using a Zeiss Axiolab pol microscope at magnifications of 50-400x. Microfacies analyses included varve counting and measurements of varve and sublayer thickness.

Description: Despite the importance of surface energy budgets (SEBs) for land-climate interactions in the Arctic, uncertainties in their prediction persist. In situ observational data of SEB components - useful for research and model validation - are collected at relatively few sites across the terrestrial Arctic, and not all available datasets are readily interoperable. Furthermore, the terrestrial Arctic consists of a diversity of vegetation types, which are generally not well represented in land surface schemes of current Earth system models. This dataset contains metadata information about surface energy budget components measured at 64 tundra and glacier sites 〉60° N across the Arctic. This information was taken from the open-access repositories FLUXNET, Ameriflux, AON, GC-Net and PROMICE. The contained datasets are associated with the publication vegetation type as an important predictor of the Arctic Summer Land Surface Energy Budget by Oehri et al. 2022, and intended to support research of surface energy budgets and their relationship with environmental conditions, in particular vegetation characteristics across the terrestrial Arctic.

Description: This dataset provides the results from Bayesian age depth modelling in OxCal for ICDP core 5017-1-A, retrieved from the deep northern Dead Sea basin in 2010/11, for the last glacial-interglacial transition between ~101 and 88.5 m sediment depth below lake floor (ca. 17-11.5 ka BP). The model was performed in OxCal v.4.4 using a P_Sequence (1,1,C(-2,2)) (Ramsey 2008; Ramsey 2009; Ramsey and Lee 2013) and includes three tephrochronological ages from Neugebauer et al. (2021) and three radiocarbon ages from Kitagawa et al. (2017).

Description: Despite the importance of surface energy budgets (SEBs) for land-climate interactions in the Arctic, uncertainties in their prediction persist. In situ observational data of SEB components - useful for research and model validation - are collected at relatively few sites across the terrestrial Arctic, and not all available datasets are readily interoperable. Furthermore, the terrestrial Arctic consists of a diversity of vegetation types, which are generally not well represented in land surface schemes of current Earth system models. This dataset comprises harmonized, standardized and aggregated in-situ observations of surface energy budget components measured at 64 sites on vegetated and glaciated sites north of 60° latitude, in the time period from 1994 till 2021. The surface energy budget components include net radiation, sensible heat flux, latent heat flux, ground heat flux, net shortwave radiation, net longwave radiation, surface temperature and albedo, which were aggregated to daily mean, minimum and maximum values from hourly and half-hourly measurements. Data were retrieved from the monitoring networks FLUXNET, AmeriFlux, AON, GC-Net and PROMICE.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: This dataset describes two 17 m long sediment cores taken from beneath two thermokarst lakes in the Yukechi Alas, Central Yakutia, Russia. The first core was taken from below an Alas thermokarst lake (YU-L7; 61.76397°N, 130.46442°E) and the second core below and Yedoma lake (YU-L15; 61.76086°N, 130.47466°E). The dataset presents biogeochemical and biomarker parameters of sediment cores YU-L7 and YU-L15. Biogeochemical analyses include total carbon (TC) content, total organic carbon (TOC) content, total nitrogen (TN) content. Biomarker parameters include the n-alkane concentration, average chain length (ACL), carbon preference index (CPI), brGDGT concentration, archaeol concentration and the isoGDGT-0 concentration. The n-alkanes were measured in the aliphatic fraction by gas chromatography-mass spectromety using a Trace GC Ultra coupled to a DSQ MS. The branched and isoprenoid glycerol dialkyl glycerol tetraethers, as well as the dialkyl glycerol diether lipid (archaeol) were measured in the NSO fraction using a Shimadzu LC-10AD high-performance liquid chromatograph coupled to a Finnigan TSQ 7000 mass spectrometer via an atmospheric pressure chemical ionization interface. The pH soil is the sediment pH which was assessed by adding 6.12 mL of 0.01 M CaCl~2~ to ~2.5 g dried sediment and measuring with a Multilab 540 (WTW) at 20°C.

Description: We present sea ice temperature and salinity data from first-year ice (FYI) and second-year ice (SYI) relevant to the temporal development of sea ice permeability and brine drainage efficiency from the early growth phase in October 2019 to the onset of spring warming in May 2020. Our dataset was collected in the central Arctic Ocean during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Expedition in 2019 to 2020. MOSAiC was an international transpolar drift expedition in which the German icebreaker RV Polarstern anchored into an ice floe to gain new insights into Arctic climate over a full annual cycle. In October 2019, RV Polarstern moored to an ice floe in the Siberian sector of the Arctic at 85 degrees north and 137 degrees east to begin the drift towards the North Pole and the Fram Strait via the Transpolar Drift Stream. The data presented here were collected during the first three legs of the expedition, so all the coring activities took place on the same floe. The end dates of legs 1, 2, and 3 were 13 December, 24 February, and 4 June, respectively. The dataset contributed to a baseline study entitled, Deciphering the properties of different Arctic ice types during the growth phase of the MOSAiC floes: Implications for future studies. The study highlights downward directed gas pathways in FYI and SYI by inferring sea ice permeability and potential brine release from several time series of temperature and salinity measurements. The physical properties presented in this paper lay the foundation for subsequent analyses on actual gas contents measured in the ice cores, as well as air-ice and ice-ocean gas fluxes. Sea ice cores were collected with a Kovacs Mark II 9 cm diameter corer. To measure ice temperatures, about 4.5 cm deep holes were drilled into the core (intervals varied by site and leg) . The temperatures were measured by a digital thermometer within minutes after the cores were retrieved. The ice cores were placed into pre-labelled plastic sleeves sealed at the bottom end. The ice cores were transported to RV Polarstern and stored in a -20 degrees Celsius freezer. Each of the cores was sub-sampled, melted at room temperature, and processed for salinity within one or two days. The practical salinity was estimated by measuring the electrical conductivity and temperature of the melted samples using a WTW Cond 3151 salinometer equipped with a Tetra-Con 325 four-electrode conductivity cell. The practical salinity represents the the salinity estimated from the electrical conductivity of the solution. The dataset also contains derived variables, including sea ice density, brine volume fraction, and the Rayleigh number.

Description: Despite the importance of surface energy budgets (SEBs) for land-climate interactions in the Arctic, uncertainties in their prediction persist. In-situ observational data of SEB components - useful for research and model validation - are collected at relatively few sites across the terrestrial Arctic, and not all available datasets are readily interoperable. Furthermore, the terrestrial Arctic consists of a diversity of vegetation types, which are generally not well represented in land surface schemes of current Earth system models. Therefore, we here provide four datasets comprising: 1. Harmonized, standardized and aggregated in situ observations of SEB components at 64 vegetated and glaciated sites north of 60° latitude, in the time period 1994-2021 2. A description of all study sites and associated environmental conditions, including the vegetation types, which correspond to the classification of the Circumpolar Arctic Vegetation Map (CAVM, Raynolds et al. 2019). 3. Data generated in a literature synthesis from 358 study sites on vegetation or glacier (〉=60°N latitude) covered by 148 publications. 4. Metadata, including data contributor information and measurement heights of variables associated with Oehri et al. 2022.

Description: This dataset provides lithological data from ICDP core 5017-1-A, retrieved from the deep northern Dead Sea basin in 2010/11, for the last glacial-interglacial transition (ca. 17-11.5 ka BP). The microfacies of the Lisan Formation was investigated between ~101 and 88.5 m sediment depth below lake floor by continuous thin section microscopy, while additional macroscopic information is provided from core catchers, as well as from over- and underlying sediment sections. Thin sections were prepared following the standard procedure by Brauer and Casanova (2001) that was adjusted for salty sediments. Thin section analyses were performed on overlapping large-scale thin sections using a Zeiss Axiolab pol microscope at magnifications of 50-400x.

Description: This dataset contains observations of water discharge rates and concentrations of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) from a polygonal tundra site in the Lena River Delta, Russia. This dataset also contains lateral carbon fluxes of DOC and DIC that were estimated from these observations. Additionally, this dataset contains vertical fluxes of carbon dioxide and methane from the same study site. All observations were recorded on Samoylov Island (N 72.377188, E 126.495144) in the summer of 2014. The abbreviations A1, A2 and B refer to three outflows on the island where the hydrological parameters were observed (A1: N 72.379991, E 126.480886; A2: N 72.380134, E 126.481433; B: N 72.381348, E 126.483482). All outflows were approximately 10 meters. More information can be found in https://doi.org/10.5194/bg-19-3863-2022.

Description: Despite the importance of surface energy budgets (SEBs) for land-climate interactions in the Arctic, uncertainties in their prediction persist. In situ observational data of SEB components - useful for research and model validation - are collected at relatively few sites across the terrestrial Arctic, and not all available datasets are readily interoperable. Furthermore, the terrestrial Arctic consists of a diversity of vegetation types, which are generally not well represented in land surface schemes of current Earth system models. This dataset describes the environmental conditions for 64 tundra and glacier sites (〉=60°N latitude) across the Arctic, for which in situ measurements of surface energy budget components were harmonized (see Oehri et al. 2022). These environmental conditions are (proxies of) potential drivers of SEB-components and could therefore be called SEB-drivers. The associated environmental conditions, include the vegetation types graminoid tundra, prostrate dwarf-shrub tundra, erect-shrub tundra, wetland complexes, barren complexes (≤ 40% horizontal plant cover), boreal peat bogs and glacier. These land surface types (apart from boreal peat bogs) correspond to the main classification units of the Circumpolar Arctic Vegetation Map (CAVM, Raynolds et al. 2019). For each site, additional climatic and biophysical variables are available, including cloud cover, snow cover duration, permafrost characteristics, climatic conditions and topographic conditions.

Description: This dataset contains over 30 marine Electrical Resistivity Tomography (ERT) profiles taken in September 2021 around Tuktoyaktuk Island (NWT / Beaufort Sea, Canada). The measurements were part of the “Mackenzie Delta Permafrost Field Campaign” (mCan2021) within the “Modular Observation solutions for Earth Systems” (MOSES) program. The collected profiles consist of numerous adjacent vertical soundings in a (quasi-symmetric) reciprocal Wenner-Schlumberger array, using a floating cable towed behind a boat. GPS records along the electrode streamer were taken, enabling the improvement of pre- processing by excluding measurements for which the cable was curved and electrode positions deviated too widely. The aim of the study was to determine the depth of the submarine permafrost. Cleaned data is provided in csv format.

Description: This collection contains permafrost related measurements in the Mackenzie Delta, NWT, Canada from the MOSES (Modular Observation Solutions for Earth Systems) field campaign in September 2021. The field campaign was focused on three subaquatic sites: a small thermokarst lake along the ITH just south of Trail Valley Creek, "Lake 3", an elongated lake with known methane occurence in the outer Mackenzie Delta, "Swiss Cheese Lake", and north and south of Tuktoyaktuk Island. At "Swiss Cheese Lake", we measured methane and CO2 concentrations in surface water and in the air above the lake, lake bed temperatures and detailed bathymetry. At "Lake 3" we measured active layer thickness on the lake banks, lake bed temperatures, and detailed bathymetry, as well as an ERT survey to estimate the talik depth below the lake. North and south of Tuktoyaktuk Island, we measured active layer thickness and sea bed temperatures and did an extensive ERT survey to obtain the depth of the subsea permafrost table. An additional passive seismic survey was carried out and the data is available at https://doi.org/10.5880/GIPP.202199.1.

Description: This dataset contains seven Electrical Resistivity Tomography (ERT) profiles taken in September 2021 at “Lake 3”, a thermokarst lake near the Inuvik-Tuktoyaktuk-Highway (ITH), about 50 km north of Inuvik (NWT, Canada). The measurements were part of the “Mackenzie Delta Permafrost Field Campaign” (mCan2021) within the “Modular Observation solutions for Earth Systems” (MOSES) program. The collected profiles consist of numerous adjacent vertical soundings in a (quasi-symmetric) reciprocal Wenner-Schlumberger array. In addition to surveys on the lake, using a floating cable towed behind a boat, two “amphibian” profiles were taken. Starting as purely terrestrial surveys using metal spike electrodes, the cable was then moved towards the lake with some of the electrodes floating on the water surface, and some still on land. The aim of the study was to determine permafrost properties on the land, to detect a possible talik beneath the lake and to especially be able to infer the transition between the two below the shoreline.