ALBERT

Description: The world's forests store large amounts of carbon (C), and growing forests can reduce atmospheric CO2 by storing C in their biomass. This has provided the impetus for world-wide tree planting initiatives to offset fossil-fuel emissions. However, forests interact with their environment in complex and multifaceted ways that must be considered for a balanced assessment of the value of planting trees. First, one needs to consider the potential reversibility of C sequestration in trees through either harvesting or tree death from natural factors. If carbon storage is only temporary, future temperatures will actually be higher than without tree plantings, but cumulative warming will be reduced, contributing both positively and negatively to future climate-change impacts. Alternatively, forests could be used for bioenergy or wood products to replace fossil-fuel use which would obviate the need to consider the possible reversibility of any benefits. Forests also affect the Earth's energy balance through either absorbing or reflecting incoming solar radiation. As forests generally absorb more incoming radiation than bare ground or grasslands, this constitutes an important warming effect that substantially reduces the benefit of C storage, especially in snow-covered regions. Forests also affect other local ecosystem services, such as conserving biodiversity, modifying water and nutrient cycles, and preventing erosion that could be either beneficial or harmful depending on specific circumstances. Considering all these factors, tree plantings may be beneficial or detrimental for mitigating climate-change impacts, but the range of possibilities makes generalisations difficult. Their net benefit depends on many factors that differ between specific circumstances. One can, therefore, neither uncritically endorse tree planting everywhere, nor condemn it as counter-productive. Our aim is to provide key information to enable appropriate assessments to be made under specific circumstances. We conclude our discussion by providing a step-by-step guide for assessing the merit of tree plantings under specific circumstances.

Description: Seaweed farming contributes substantial amounts of organic carbon to the ocean, part of which can be locked for a long term in the ocean and perform the function of ocean carbon sequestration, and the other part can be converted into inorganic carbon through microbial mineralization and aerobic respiration, affecting the pCO2, pHT and dissolved oxygen of seawater. It is generally believed that seaweed farming will cause the seawater to become a sink of CO2 due to carbon fixation by macroalgal photosynthesis. However, little attention has been paid to the fact that seaweed farming environment may sometimes become a source rather than a sink of CO2. Here, through in-situ mesocosm cultivation experiments and eight field investigations covering different kelp growth stages in an intensive farming area in China, we found that compared with the surrounding seawater without kelps, the seawater at the fast-growth stage of kelp was a sink of CO2 (pCO2 decreased by 17−73 μatm), but became a source of CO2 at the aging stage of kelp (pCO2 increased by 20−37 μatm). Concurrently, seawater pHT experienced a transition from increase (by 0.02−0.08) to decline (by 0.03−0.04). In-situ mesocosm cultivation experiments showed that the positive environmental effects (i.e., pCO2 decrease and pHT increase) induced by kelps at the early growth stage could be offset within only 3 days at the late-growth and aging stages. The release of dissolved organic carbon by kelps at the late growth stage increased significantly, supporting the enhancement in microbial abundance and respiration, which was manifested by the remarkable decrease in seawater dissolved oxygen, ultimately leading to CO2 release exceeding photosynthetic CO2 absorption. This study suggests that mature farmed kelps should be harvested in time to best utilize their carbon sink function and environmental benefits, which has guiding significance for the rational management of seaweed farming.

Description: Highlights: • Inhibitory potential of eelgrass microbiome against aquatic and fecal pathogens • Isolation of epiphytes and endophytes associated with eelgrass leaves and roots • Particularly leaf epibiotic bacteria exhibit significant antimicrobial activity. • Rich secondary metabolite composition by untargeted metabolomics • Potential involvement of eelgrass microbiome in seagrass ecosystem services Seagrass meadows provide crucial ecosystem services for coastal environments and were shown to reduce the abundance of waterborne pathogens linked to infections in humans and marine organisms in their vicinity. Among potential drivers, seagrass phenolics released into seawater have been linked to pathogen suppression, but the potential involvement of the seagrass microbiome has not been investigated. We hypothesized that the microbiome of the eelgrass Zostera marina, especially the leaf epiphytes that are at direct interface between the seagrass host and the surrounding seawater, inhibit waterborne pathogens thereby contributing to their removal. Using a culture-dependent approach, we isolated 88 bacteria and fungi associated with the surfaces and inner tissues of the eelgrass leaves (healthy and decaying) and the roots. We assessed the antibiotic activity of microbial extracts against a large panel of common aquatic, human (fecal) and plant pathogens, and mined the metabolome of the most active extracts. The healthy leaf epibiotic bacteria, particularly Streptomyces sp. strain 131, displayed broad-spectrum antibiotic activity superior to some control drugs. Gram-negative bacteria abundant on healthy leaf surfaces, and few endosphere-associated bacteria and fungi also displayed remarkable activities. UPLC-MS/MS-based untargeted metabolomics analyses showed rich specialized metabolite repertoires with low annotation rates, indicating the presence of many undescribed antimicrobials in the extracts. This study contributes to our understanding on microbial and chemical ecology of seagrasses, implying potential involvement of the seagrass microbiome in suppression of pathogens in seawater. Such effect is beneficial for the health of ocean and human, especially in the context of climate change that is expected to exacerbate all infectious diseases. It may also assist future seagrass conservation and management strategies.

Description: Total alkalinity (TA) is an important variable of the ocean carbonate system. In coastal oceans, carbonate system dynamics are controlled by a range of processes including photosynthesis and respiration, calcification, mixing of water masses, continental inputs, temperature changes, and seasonal upwelling. Assessments of diel, seasonal and interannual variations in TA are required to understand the carbon cycle in coastal oceans. However, our understanding of these variations remains underdeveloped due to limitations in observational techniques. Autonomous TA measurements are therefore required. In this study, an in situ TA analyzer (ISA-TA) based on a single-point titration with spectrophotometric pH detection was deployed in Tong'an Bay, Xiamen, China, over a five-month period in 2021 to determine diel and seasonal TA variations. The TA observations were combined with an artificial neural network (ANN) model to construct TA prediction models for this area. This provided a simple method to investigate TA variations in this region and was applied to predict surface water TA between March and April 2021. The in situ TA observations showed that TA values in Tong'an Bay varied within a range from 1931 to 2294 μmol kg−1 over the study period, with low TA in late winter, early summer and late summer, and high TA in early winter. The TA variations in late summer and early winter were mainly controlled by mixing of water bodies. The diel variations of TA were greatly determined by tides, with a diel amplitude of 9 to 247 μmol kg−1. The ANN model used temperature, salinity, chlorophyll, and dissolved oxygen to estimate TA, with a root-mean-square error (RMSE) of ∼14 μmol kg−1, with salinity as the input variable with the greatest weight. The approach of combining ISA-TA observations with an ANN model can be extended to study the carbonate system in other coastal regions.

Description: Cephalopods are well known for their cognitive capabilities and unique behavioural repertoires. Yet, certain life strategies and behaviours are still not fully understood. For instance, coastal octopuses have been documented (mainly through citizen science and TV documentaries) to occasionally leave the water and crawl in intertidal areas. Yet, there is a complete lack of knowledge on this behaviour's physiological and biochemical basis. Within this context, this study aimed to investigate, for the first time, physiological (routine and maximum metabolic rates and aerobic scope) and biochemical (i.e., antioxidant enzymes activities, heat shock protein and ubiquitin levels, DNA damage, lipid peroxidation) responses of the common octopus, Octopus vulgaris, to emersion. The octopuses’ physiological performance was determined by measuring metabolic rates in different emersion treatments and biochemical markers. The size-adjusted maximum metabolic rates (MMRadj) of octopuses exposed to 2:30 min of air exposure followed by re-immersion did not differ significantly from the MMRadj of the chased individuals (control group). Yet, most biochemical markers revealed no significant differences among the different emersion treatments. Our findings showed that O. vulgaris could tolerate exposure to short-term emersion periods due to an efficient antioxidant machinery and cellular repair mechanisms. Alongside, we argue that the use of atmospheric air through the mucus-covered gills and/or cutaneous respiration may also help octopus withstand emersion and crawling on land.

Description: 〈p〉〈em〉〈span〉This study delves into the management of electronic waste (e-waste) stemming from the disposal of personal electronic items and mobile phones, primarily in response to the remarkable surge in the utilization of these devices within the Hassan city populace in recent years. The principal objectives revolved around investigating the existing disposal methods for electronic devices including mobile phones and collecting fundamental data concerning their disposal practices within the geographical confines of Hassan city of Karnataka State. Additionally, an endeavor was undertaken to gauge the level of awareness among respondents regarding the potential hazards posed by e-waste. It was observed that a significant proportion of the Hassan population typically retains especially electronic devices is cell phones, once these devices become outdated and obsolete. Among the prevalent disposal methods, the most widespread approach involves selling these gadgets to scrap dealers or junk shops, whereas recycling practices remain relatively underutilized. Notably, a mere minority of individuals engage in recycling activities. An intriguing revelation emerged, with 65% of respondents expressing concern about the adverse repercussions of improper e-waste disposal on human health and the environment. Astonishingly, all respondents admitted to having no knowledge of the fate of their discarded electronic devices. Based on the findings gleaned from this survey, it is strongly recommended that a comprehensive review be conducted on the overarching management of e-waste stemming from this electronic waste including mobile phones, gadgets in the Hassan city of Karnataka State. The purpose of these surveys and data collection endeavors is to approximate the volume of e-waste generated through the disposal of these devices. This information is envisioned to assist stakeholders and government agencies in formulating effective and efficient legislation and policies for the proficient management of e-waste〈/span〉〈/em〉〈/p〉

Description: 〈p〉〈em〉Indian Railroads is one of the largest railroad systems in the World. The Indian railway system has grown significantly over the years, as seen by the massive construction of its railroads; nonetheless, some accidents are caused by fractures in the railway track. Splits may occur because of the track's expansion or contraction brought on by seasonal variations. This study proposes a crack monitoring vehicle that employs an ultrasonic sensor to detect fractures on railway tracks and uses an Arduino Uno to facilitate the GSM and GPS module to send an SMS to the testing station, thereby mitigating the problems caused by these cracks. This intelligent system works like a remote monitoring system which gives an alert to stop the passage of trains in that path. The proposed model involves the use of Arduino, ultrasonic sensor, buzzer, GSM module, and GPS module.〈/em〉〈/p〉

Description: RV Meteor M197 EMS-PS ('Eastern Mediterranean Sea - Process Study'), 30.12.2023 – 06.02.2024

Description: We investigate the drivers of global and regional changes in the potential for photovoltaic (PV) power production from the pre-industrial (1850) to present-day (1985-2014) and until the end of the century (2071-2100), based on output from the Coupled Model Intercomparison Project phase six (CMIP6). Our assessment separates regional contributions from changes in clouds, humidity, temperature, aerosols, and wind speed to the changes in PV power potentials for the first time. Present-day PV power potentials are adversely affected by anthropogenic aerosols compared to the pre-industrial, with a global decrease of the PV power potential by -1.3%. Our results highlight a globally averaged decrease in future PV power potentials primarily driven by temperature and humidity increases by -1.2% to more than -3.5%, depending on the scenario. Regionally different contributions of changes in clouds and aerosols cause heterogeneous spatial patterns in changes of PV potentials, with typically stronger (weaker) influences from clouds (aerosols) in SSP5-8.5 compared to SSP1-2.6. Our results imply that the uncertain response of clouds to warming and aerosol effects are hurdles in quantifying changes in the regional potentials for PV power production.

Description: RV Meteor M197 EMS-PS ('Eastern Mediterranean Sea - Process Study'), 30.12.2023 – 06.02.2024

Description: The sustainability of southern Africa’s natural and managed marine and terrestrial ecosystems is threatened by overuse, mismanagement, population pressures, degradation, and climate change. Counteracting unsustainable development requires a deep understanding of earth system processes and how these are affected by ongoing and anticipated global changes. This information must be translated into practical policy and management interventions. Climate models project that the rate of terrestrial warming in southern Africa is above the global terrestrial average. Moreover, most of the region will become drier. Already there is evidence that climate change is disrupting ecosystem functioning and the provision of ecosystem services. This is likely to continue in the foreseeable future, but impacts can be partly mitigated through urgent implementation of appropriate policy and management interventions to enhance resilience and sustainability of the ecosystems. The recommendations presented in the previous chapters are informed by a deepened scientific understanding of the relevant earth system processes, but also identify research and knowledge gaps. Ongoing disciplinary research remains critical, but needs to be complemented with cross-disciplinary and transdisciplinary research that can integrate across temporal and spatial scales to give a fuller understanding of not only individual components of the complex earth-system, but how they interact.

Description: The southern African subcontinent and its surrounding oceans accommodate globally unique ecoregions, characterized by exceptional biodiversity and endemism. This diversity is shaped by extended and steep physical gradients or environmental discontinuities found in both ocean and terrestrial biomes. The region’s biodiversity has historically been the basis of life for indigenous cultures and continues to support countless economic activities, many of them unsustainable, ranging from natural resource exploitation, an extensive fisheries industry and various forms of land use to nature-based tourism. Being at the continent’s southern tip, terrestrial species have limited opportunities for adaptive range shifts under climate change, while warming is occurring at an unprecedented rate. Marine climate change effects are complex, as warming may strengthen thermal stratification, while shifts in regional wind regimes influence ocean currents and the intensity of nutrient-enriching upwelling. The flora and fauna of marine and terrestrial southern African biomes are of vital importance for global biodiversity conservation and carbon sequestration. They thus deserve special attention in further research on the impacts of anthropogenic pressures including climate change. Excellent preconditions exist in the form of long-term data sets of high quality to support scientific advice for future sustainable management of these vulnerable biomes.

Description: The applicability of the Gravity Recovery and Climate Experiment (GRACE) level 1B range-rate data for detecting gravity changes under the influence of strong earthquakes (M6.0-6.9) has been investigated. The most common product of the GRACE mission is the level 2, science data, as the spherical harmonic Stokes’ coefficients of the geopotential. These coefficients have been generated from Level 1B data which has resulted in missing some information during the smoothing process. In this study, the GRACE level 1B K-band range-rate measurements over three selected cells in Iran were analyzed, including two cells containing the epicenters of the Boroujerd earthquake (6.1 Mw) and the Zarand earthquake (6.4 Mw), which occurred on March 31, 2006, and February 22, 2005, respectively, and one cell far enough from those two cells. Additionally, the range-rate time series attributed to Iran's main catchments containing the above-mentioned zones have been extracted to distinguish between the effects of earthquakes and hydrology on the range-rate time series. Besides, the impact of factors other than earthquakes such as tide and non-gravitational accelerations acting on the GRACE satellites has been corrected. To better explore the extracted signals, their details have been derived using the wavelet transforms and the corresponding anomalies have been detected using the boxplot method. The considerable anomalies that have been observed in areas within or close to the earthquakes' epicenters before and after the earthquakes indicate that the GRACE and GRACE Follow-On range-rate time series can be considered as one of the potential precursors of a strong earthquake.

Description: سپیدایی از فراسنجﻫﺎی کلیدی در ﻣﻄﺎﻟﻌﺎت آب و ﻫﻮاﻳﻲ ﻣﻲﺑﺎﺷﺪ. بررسی آب و هواشناسی سپیدایی می‌تواند ابزاری برای شناخت تغییرات محیطی باشد. ﺳﻨﺠﻨﺪه مودیس سپیدایی سطح زﻣﻴﻦ را ﺑﻄﻮر ﻣﺴﺘﻤﺮ در ﻣﻘﻴﺎﺳﻲ ﺟﻬﺎﻧﻲ و ﺑﺎ ﻗﺪرت ﺗﻔﻜﻴﻚ ﻣﻜﺎﻧﻲ مناسب ﺗﻮﻟﻴﺪ و در دسترس پژوهشگران ﻗﺮار می‌دهد. در این پژوهش جهتِ واکاوی آب و هواشناسی سپیدایی ایران‌، نخست داده‌های فراورده MCD43A4 سنجنده مودیس در محدوده ایران در بازه زمانی 1/1/2001 تا 30/12/2021 با تفکیک مکانی 500 متری و تفکیک زمانی روزانه از وبگاه ناسا برداشت شد. پس از پیش پردازش‌های لازم، میانگین بلندمدت ماهانه، فصلی و سالانه سپیدایی ایران محاسبه گردید. یافته‌ها در مقیاس ماهانه نشان داد که در ماه‌های سرد سال( Jan, Feb, Mar ) که ماه‌های برفپوش ایران شناخته می‌شوند، سپیدایی ایران بیشینه شده و ماه‌های گذار فروکش کرده و سپس در ماه‌های گرم سال (June, July, Aug) به سبب خشکی زمین و افزایش دمای رویه زمین دوباره افزایش می‌یابد. این رفتار دو سویه در مقیاس فصلی نیز آشکار است. بطوری که سپیدایی ایران در فصول زمستان و تابستان بیشینه و در فصول بهار و پاییز (فصول گذار) کمینه می‌باشد. همچنین یافته‌ها گویای آن است که میانگین بلندمدت سپیدایی ایران حدود 5/12 درصد است. با آگاهی از محدود بودن پوشش برفی ایران، پایین بودن سپیدایی ایران طبیعی به نظر می‌رسد.

Description: Evaluating the susceptibility of regional climates to climate change gives a pattern to realistically analyze the probable future climate changes. This paper investigates human influence on variations in precipitation extremes in Iran by evaluating precipitation data provided from 286 rain-gage stations during 1967-2010 and general circulation simulation results of CanESM2 model. This investigation was based on six forcing factors including natural external (volcanic aerosol, solar radiation), anthropogenic and a combination of them, Green House Gases (GHGs), change of land use, and anthropogenic aerosols. Seven precipitation indices namely Rx1day (Annual maximum 1-day precipitation), Rx5day (Annual maximum 5-day precipitation), R10mm (Annual count of days where daily precipitation is more than 10 mm), R20mm (Annual count of days where daily precipitation is more than 20 mm), CDD (Consecutive dry days), CWD (Consecutive wet days), and PRCPTOT (Annual total wet day precipitation) have been analyzed via the optimal fingerprint method. The results revealed that Rx1day, Rx5day and CWD increased, while R10mm, R20mm, CDD, and PRCPTOT decreased among which CDD and Rx1day indices with values of 18.4% and 10.9%, respectively showed significant variations. Furthermore, the obtained results implied that only the effect of anthropogenic forcing with a value of 1.4 was detected and attributed in CDD variations, also ANT caused increase in the return period of a 20-year event by 1.9 year for CDD. Although human-induced forcing factors presented marked trends in some cases, their effects were not generally detected and attributed on the change in the observations, apart from one exception.

Description: گردوخاک پدیده هواشناسی رایج در مناطق خشک و نیمه خشک جهان است که در اثر عوامل طبیعی یا انسانی ایجاد می‌شود. شناسایی چشمه‌های فعال گردوخاک نخستین گام برای مقابله با آن و کاهش پیامدهای مخرب آن است. برای این منظور از دو شاخص عمق نوری هواویزها (AOD) و اختلاف بهنجار شده پوشش گیاهی (NDVI) از سنجنده MODIS ماهواره Terra برای دو دهه گذشته (2020-2001) استفاده شده است. برای بررسی چشمه‌های فعال هواویز در منطقه مورد مطالعه درصد فراوانی آستانه‌های هواویزها با سه آستانه 0.3، 0.5و 1 مورد بررسی قرار گرفت. بیشینه مقادیر AOD مربوط به فصول بهار و تابستان است. بطور کلی شش کانون اصلی هواویزها بر اساس مقادیر AOD و شاخص FoO برای منطقه غرب آسیا قابل تشخیص است. این کانون‌های هواویز در پهنه اقلیمی بیابانی گرم و خشک (BWh) دیده می‌شوند. تنها کانون هووایز موثر در شمال شرقی ایران در پهنه اقلیمی بیابانی خشک و سرد (BWk) در کشور ترکمنستان قرار دارد. بررسی ماتریس ضریب همبستگی هواویزها با پوشش گیاهی نشان ازرابطه معکوس دارد، البته این رابطه بیشتر برای چشمه‌های هواویزها صادق است. فارغ از نقش تعیین کننده ویژگی‌های سطحی در رخداد هواویزها، دو پدیده هواشناسی همانند باد شمال تابستانه و باد 120 روزه سیستان در تشکیل کانون‌هایی با مقادیر AOD بالاتر 0.5 و 1 نقش تعیین کننده‌‌ای دارند.

Description: بازتابسنجی تداخلی GNSS را میتوان بعنوان یکی دیگر از روشهای سنجش از دور برای پایش رطوبت خاک بصورت پیوسته و البته در مقیاس محلی در نظر گرفت که در وضعیتهای مختلف جوی مانند شرایط بارانی و مه آلود و در شرایط متفاوت نور و روشنایی مانند روز و شب قابل اجرا است. سیگنالهای بازتابی از سطح زمین توسط آنتنهای GNSS قابل دریافت است. تغییرات در رطوبت خاک باعث تغییر در مقدار مؤلفه نسبت سیگنال به نویز SNRسیگنال‌های بازتابی میشود. با تجزیه و تحلیل سیگنالهای بازتابی، میتوان به اطلاعات مفیدی در مورد سطح بازتاب دست یافت. SNR به شدت به رطوبت خاک وابسته است. در این تحقیق داده های ایستگاه P038 در منطقه نیومکزیکو مورد استفاده قرار میگیرد. بدینصورت که از سیگنالهای چندمسیری برای برآورد تغییرات رطوبت خاک در طول چهار سال، از 2017 تا 2020 استفاده میشود. طبق برآورد انجام شده سطح محتوای حجمی آب در سال 2017، برابر 8/88 میباشد، که در سال 2018 به 11/74 افزایش مییابد. سپس اندکی کاهش یافته و در سال 2019 به 10/88 رسیده و نهایتاً در سال 2020 به 12/49 افزایش مییابد. در این مقاله کارائی مدل شبکه عصبی LSTM در پیش بینی سری زمانی رطوبت حجمی خاک بدست آمده از تداخل سیگنالهای بازتابی GNSS مورد ارزیابی قرار می‌گیرد. آموزش مدل با استفاده از 80 درصد مشاهدات ایستگاه انجام میگیرد. با به روزرسانی وضعیت شبکه با مقادیر مشاهده شده به جای مقادیر پیش بینی شده، مقدار جذر خطای مربعی میانگین از 0/09 به 0/04 کاهش یافته و پیش بینی ها دقیقتر انجام میشوند.

Description: Abstract Subsurface channels are stratigraphic features in seismic data that can act as reservoirs or conduits for hydrocarbons. However, detecting and characterizing these channels is challenging due to the limitations of seismic resolution and the complexity of the subsurface geology. Seismic inversion is a technique that can enhance the seismic data by transforming the seismic traces into quantitative estimates such as acoustic impedance (AI), which is a key reservoir rock property. AI inversion can help to identify and delineate the subsurface channels by providing more contrast and detail of the channel geometry, fill, and surrounding sediments. Seismic inversion is often challenged by the non-uniqueness, ambiguity, and uncertainty of the inversion results due to noise and band-limited data. This paper uses a fuzzy model-based seismic inversion method that integrates prior information and fuzzy clustering constraints to produce more realistic and reliable AI models. This method assigns data points to multiple clusters with varying degrees of membership, which can capture the overlapping of AI values of different geological formations. The method is applied to the 3D Poseidon seismic data from the Browse Basin, offshore Western Australia, and the results are compared with those of conventional model-based inversion. Since there is no well-data in an interest channel zone, a qualitative evaluation with seismic attributes is performed. The subsurface structures are further interpreted by various seismic attributes. The comparison shows the fuzzy model-based inversion method can improve the resolution, contrast, and stability of the AI models and reveal more detail of the subsurface geology.

Description: یکی از چالش‌های اصلی در بکارگیری مدل‌های ژئوپتانسیلی جهانی، محاسبه توابع لژاندر وابسته نوع اول بر اساس فرمول-های بازگشتی معمول است. از آنجاییکه اکثر نرم‌افزارهای محاسباتی به طور پیش‌فرض از فرمت «دقت مضاعف» در محاسبات استفاده می‌کنند، یک سوال مهم این است که آیا این سطح دقت برای محاسبه توابع لژاندر وابسته نوع اول و ارزیابی مدل‌های ژئوپتانسیلی کافی است؟ نتایج نشان می‌دهد که محاسبه توابع لژاندر در درجه 2190، معادل بالاترین درجه مدل‌های ژئوپتانسیلی جهانی موجود، حتی با بکارگیری دقت مضاعف، برای عرض‌های کروی در بازه [ʹ33˚78 وʹ20˚56] از دقت کافی برخوردار نیست، که بیشترین کاهش دقت در عرض کروی 60 درجه رخ می‌دهد. همچنین نتایج نشان می‌دهد که در عرض کروی 60 درجه، محاسبه توابع لژاندر در درجات بالاتر از 2029، دچار افت دقت شده و این افت دقت با افزایش درجه تشدید می‌گردد. بر اساس نتایج، محاسبه پتانسیل ثقل و شتاب ثقل تا درجه 2190، به ترتیب در محدوده عرض‌های کروی ازʹ32˚57 تاʹ13˚60 و ازʹ41˚57 تا ʹ13˚60 دچار افت شدید دقت می‌شود. از نتایج ما درمی‌یابیم که حداکثر درجه بسط برای محاسبه دقیق پتانسیل ثقل و شتاب ثقل برای تمام عرض‌های کروی، به ترتیب درجه 2065 و 2071 است. در این تحقیق، ما نشان می‌دهیم که برای محاسبه توابع لژاندر بر اساس روابط بازگشتی و تولید تابعک‌های میدان ثقل بر اساس مدل‌های ژئوپتانسیلی درجات بالای کنونی، نیازمند حفظ «دقت مضاعف طویل» در تمام فرایند محاسباتی هستیم.

Description: 〈p〉〈em〉Road safety is a critical concern in the modern world, where advancements in technology have made our lives easier but have also given rise to increased traffic hazards and road accidents. The "Car Accident Detector and Informer" project is an innovative system aimed at enhancing road safety by accurately detecting and informing about car accidents in real-time. This project integrates advanced sensors, microcontroller technology, and communication protocols to create an efficient accident detection and notification system. Utilizing GPS and GSM technology for precise location tracking and instant notifications, this system has the potential to reduce emergency response times, save lives, and minimize property damage. This research paper presents a detailed overview of the project, including its objectives, working principles, components, advantages, disadvantages, and prospects.〈/em〉〈/p〉

Description: 〈p〉〈em〉Spatiotemporal data analytics is a dynamic field that seeks to extract valuable information from data that integrates both spatial and temporal dimensions. This article explores the importance of this emerging field and its applications in a variety of fields, including environmental science, public health, and urban planning. Spatiotemporal data analysis addresses important research questions, such as determining event probabilities, understanding change patterns, identifying associations between events, and predicting events Future. However, this comes with many challenges, including managing large datasets, ensuring data quality, dealing with spatial and temporal autocorrelation, and more. To address these challenges, proposed solutions include data reduction and sampling, dimensionality reduction, data compression, use of spatial and temporal indexes, parallel and distributed processing, data filtering and pre- processing. Furthermore, strategies to handle spatial and temporal autocorrelation include exploratory data analysis, using spatial weight matrices, including spatially lagged variables, and regression models. spatial attribution, cluster analysis, etc for spatial autocorrelation and for temporal autocorrelation, solutions include time series analysis, differencing, ARIMA models, lagged variables, time series decomposition, exponential smoothing, state space modelling, machine learning, cross-validation, and regularization techniques. These approaches provide valuable insights to address the complexity of spatio-temporal data analysis and unlock its potential in various fields.〈/em〉〈/p〉

Description: 〈p〉〈em〉Diamond drilling, a core drilling technique employing diamond-encrusted drill bits, has emerged as a critical method for extracting cylindrical rock samples from diverse geological formations. This article provides an extensive overview of diamond drilling, encompassing its equipment, applications, challenges, and its pivotal role in geological exploration, mining, and construction projects. The versatility of diamond drilling is evident in its adaptability to various rock types, spanning the gamut from soft sedimentary strata to formidable crystalline structures. In mining, it serves as an indispensable tool for assessing the quality, depth, and size of mineral deposits. Likewise, in construction and civil engineering, diamond drilling aids in ascertaining geological conditions for safe and stable foundation design. Environmental considerations are paramount in contemporary drilling practices, with containment measures for drilling fluids to mitigate ecological impacts. Safety precautions are rigorously adhered to, ensuring the well-being of workers and the integrity of drilling operations. Furthermore, core samples extracted through diamond drilling are instrumental in geological investigations. These samples, meticulously analyzed, yield insights into rock composition, mineral content, and geological structures. They inform decisions in resource exploration, mine planning, and construction project management. This review underscores the invaluable contributions of diamond drilling to our understanding of the Earth's subsurface, emphasizing its adaptability, environmental consciousness, and safety. By examining the critical aspects of this technique, this article illuminates the profound impact of diamond drilling on various industries and the scientific community, positioning it as an indispensable tool for unlocking the secrets hidden beneath the Earth's surface.〈/em〉〈/p〉

Description: Beryllium isotopes have emerged as a quantitative tracer of continental weathering, but accurate and precise determination of the cosmogenic 10 Be and stable 9 Be in seawater is challenging, because seawater contains high concentrations of matrix elements but extremely low concentrations of 9 Be and 10 Be. In this study, we develop a new, time‐efficient procedure for the simultaneous preconcentration of 9 Be and 10 Be from (coastal) seawater based on the iron co‐precipitation method. The concentrations of 9 Be, 10 Be, and the resulting 10 Be/ 9 Be ratio for Changjiang Estuary water derived from the new procedure agree well with those obtained from the conventional procedure requiring separate preconcentration for 9 Be and 10 Be determinations. By avoiding the separate preconcentration, our newly developed procedure contributes toward more time‐efficient handling of samples, less sample cross‐contamination, and a more reliable 10 Be/ 9 Be ratio. Prior to this, we validated the iron co‐precipitation method using artificial seawater and natural water samples from the Amazon Estuary regarding: (1) the “matrix effect” for Be analysis, (2) its extraction efficiency for pg g −1 levels Be in the presence and absence of organic matter, and (3) the data comparability with another preconcentration method. We calculated that for the determination of 9 Be and 10 Be in most open ocean seawater with typical 10 Be concentrations of 〉 500 atoms g −1 , good precisions (〈 5%) can be achieved using less than 3 liters of seawater compared to more than 20 liters routinely used previously. Even for coastal seawater with extremely low 10 Be concentration (e.g., 100 atoms g −1 ), we estimate a maximum amount of 10 liters to be adequate.

Description: تعیین لبه و موقعیت افقی ساختارهای زمین‌شناسی یکی از مراحل اساسی در تفسیر داده‌های میدان پتانسیل محسوب می‌گردد. در این مقاله مثبت‌ترین و منفی‌ترین انحنا داده‌های گرانی تجزیه و تحلیل گردیده و فیلتری کارآمدتر با استفاده از نشانگرهای انحنا و ترکیبات آن‌ها برای تشخیص گوشه‌های ساختارها و چشمه‌های مدفون گرانی معرفی و استفاده گردیده است. روش پیشنهادی که فیلتر انحنای هیبریدی مثبت و منفی (یا به اختصار PNH) نامیده می‌شود، مثبت‌ترین و منفی‌ترین انحناها را با تنظیم فرمول و جمع وزنی در یک انحنا ترکیب و از مزایای دو انحنا مثبت و منفی برای بهبود تشخیص لبه داده‌های گرانی استفاده می‌نماید. بدین منظور ابتدا توانایی فیلتر PNH با در نظر گرفتن فرض‌های مختلف چگالی (مثبت، منفی و مثبت-منفی) برای مدل گرانی نسبتا پیچیده مصنوعی حاصل از منشورهای مدفون بدون نوفه و همراه با نوفه تصادفی مورد بررسی قرار گرفته که نتایج به دست آمده بر روی مدل‌های مصنوعی نشان می‌دهد فیلتر انحنای هیبریدی مثبت و منفی، از توانایی نسبتا خوبی برای تشخیص مرزهای افقی ساختارهای مدفون با چگالی و عمق‌های مختلف برخوردار است. همچنین از فیلترهای استاندارد تعیین گوشه مانند، مشتق قائم مرتبه دوم گرانی و فیلتر زاویه تیلت یا کجی برای مقایسه و صحت‌سنجی توانایی فیلترهای نشانگر انحنا بر روی مدل مصنوعی استفاده شده است. در ادامه کیفیت فیلتر پیشنهادی PNH ابتدا بر روی داده‌های واقعی یک معدن طلا واقع در منطقه ویتواترزند (آفریقای جنوبی) و سپس بر روی داده‌های گرانی مربوط به گنبد نمکی آجی‌چای (ایران) مورد بررسی و مطالعه قرار گرفته است.

Description: Ice calved from the Antarctic and Greenland Ice Sheets or tidewater glaciers ultimately melts in the ocean contributing to sea-level rise. Icebergs have also been described as biological hotspots due to their potential roles as platforms for marine mammals and birds, and as micronutrient fertilizing agents. Icebergs may be especially important in the Southern Ocean where availability of the micronutrients iron and manganese extensively limits marine primary production. Whilst icebergs have long been described as a source of iron to the ocean, their nutrient signature is poorly constrained and it is unclear if there are regional differences. Here we show that 589 ice fragments collected from floating ice in contrasting regions spanning the Antarctic Peninsula, Greenland, and smaller tidewater systems in Svalbard, Patagonia and Iceland have similar characteristic (micro)nutrient signatures with limited or no significant differences between regions. Icebergs are a minor or negligible source of macronutrients to the ocean with low concentrations of NOx (NO3 + NO2, median 0.51 µM), PO4 (median 0.04 µM), and dissolved Si (dSi, median 0.02 µM). In contrast, icebergs deliver elevated concentrations of dissolved Fe (dFe; mean 82 nM, median 12 nM) and Mn (dMn; mean 26 nM, median 2.6 nM). A tight correlation between total dissolvable Fe and Mn (R2 = 0.95) and a Mn:Fe ratio of 0.024 suggested a lithogenic origin for the majority of sediment present in ice. Total dissolvable Fe and Mn retained a strong relationship with sediment load (both R2 = 0.43, p〈0.001), whereas weaker relationships were observed for dFe, dMn and dSi. Sediment load for Antarctic ice (median 9 mg L-1, n=144) was low compared to prior reported values for the Arctic. A particularly curious incidental finding was that melting samples of ice were observed to rapidly lose their sediment load, even when sediment layers were embedded within the ice and stored in the dark. Our results demonstrated that the nutrient signature of icebergs is consistent with an atmospheric source of NOx and PO4. Conversely, high Fe and Mn, and modest dSi concentrations, are associated with englacial sediment, which experiences limited biogeochemical processing prior to release into the ocean.

Description: Microbial carbonates are common components of Quaternary tropical coral reefs. Previous studies revealed that sulfate-reducing bacteria trigger microbial carbonate precipitation in supposedly cryptic reef environments. Here, using petrography, lipid biomarker analysis, and stable isotope data, we aim to understand the formation mechanism of microbial carbonate enclosed in deep fore reef limestones from Mayotte and Mohéli, Comoro Islands, which differ from other reefal microbial carbonates in that they contain less microbial carbonate and are dominated by numerous sponges. To discern sponge-derived lipids from lipids enclosed in microbial carbonate, lipid biomarker inventories of diverse sponges from the Mayotte and Mohéli reef systems were examined. Abundant peloidal, laminated, and clotted textures point to a microbial origin of the authigenic carbonates, which is supported by ample amounts of mono- O -alkyl glycerol monoethers (MAGEs) and terminally branched fatty acids; both groups of compounds are attributed to sulfate-reducing bacteria. Sponges revealed a greater variety of alkyl chains in MAGEs, including new, previously unknown, mid-chain monomethyl- and dimethyl-branched MAGEs, suggesting a diverse community of sulfate reducers different from the sulfate-reducers favoring microbialite formation. Aside from biomarkers specific for sulfate-reducing bacteria, lipids attributed to demosponges (i.e., demospongic acids) are also present in some of the sponges and the reefal carbonates. Fatty acids attributed to demosponges show a higher diversity and a higher proportion in microbial carbonate compared to sponge tissue. Such pattern reflects significant taphonomic bias associated with the preservation of demospongic acids, with preservation apparently favored by carbonate authigenesis.

Description: Marine methane hydrate is an ice-like substance that is stable in sediment around marine continental margins where water depths are greater than ~450–700 m. The release of methane due to melting of hydrates is considered to be a mechanism for past global carbon-cycle perturbations and could exacerbate ongoing anthropogenic climate change. Increases in bottom-water temperature at the landward limit of marine hydrate around continental margins, where vulnerable hydrate exists at or below the seabed, cause methane to vent into the ocean. However, this setting represents only ~3.5% of the global hydrate reservoir. The potential for methane from hydrate in deeper water to reach the atmosphere was considered negligible. Here we use three-dimensional (3D) seismic imagery to show that, on the Mauritanian margin, methane migrated at least 40 km below the base of the hydrate stability zone and vented through 23 pockmarks at the shelf break, probably during warmer Quaternary interglacials. We demonstrate that, under suitable circumstances, some of the 96.5% of methane bound in deeper water distal hydrates can reach the seafloor and vent into the ocean beyond the landward limit of marine hydrate. This reservoir should therefore be considered for estimating climate change-induced methane release during a warming world.

Description: Aim: Human activities have introduced numerous non-native species (NNS) worldwide. Understanding and predicting large-scale NNS establishment patterns remain fundamental scientific challenges. Here, we evaluate if NNS composition represents a proportional subset of the total species pool available to invade (i.e. total global biodiversity), or, conversely, certain taxa are disproportionately pre-disposed to establish in non-native areas. Location: Global. Time period: Present day. Major taxa studied: Global diversity. Methods: We compiled one of the most comprehensive global databases of NNS (36,822 established species) to determine if NNS diversity is a representative proportional subset of global biodiversity. Results: Our study revealed that, while NNS diversity mirrors global biodiversity to a certain extent, due to significant deviance from the null model it is not always a representative proportional subset of global biodiversity. The strength of global biodiversity as a predictor depended on the taxonomic scale, with successive lower taxonomic levels less predictive than the one above it. Consequently, on average, 58%, 42% and 28% of variability in NNS numbers were explained by global biodiversity for phylum, class and family respectively. Moreover, global biodiversity was a similarly strong explanatory variable for NNS diversity among regions, but not habitats (i.e. terrestrial, freshwater and marine), where it better predicted NNS diversity for terrestrial than for freshwater and marine habitats. Freshwater and marine habitats were also greatly understudied relative to invasions in the terrestrial habitats. Over-represented NNS relative to global biodiversity tended to be those intentionally introduced and/or ‘hitchhikers’ associated with deliberate introductions. Finally, randomness is likely an important factor in the establishment success of NNS. Main conclusions: Besides global biodiversity, other important explanatory variables for large-scale patterns of NNS diversity likely include propagule and colonization pressures, environmental similarity between native and non-native regions, biased selection of intentionally introduced species and disparate research efforts of habitats and taxa.

Description: Severe storm flooding poses a major hazard to the coasts of north‐western Europe. However, the long‐term recurrence patterns of extreme coastal flooding and their governing factors are poorly understood. Therefore, high‐resolution sedimentary records of past North Atlantic storm flooding are required. This multi‐proxy study reconstructs storm‐induced overwash processes from coastal lake sediments on the Shetland Islands using grain‐size and geochemical data, and the re‐analysis of historical data. The chronostratigraphy is based on Bayesian age–depth modelling using accelerator mass spectrometry 14 C and 137 Cs data. A high XRF‐based Si/Ti ratio and the unimodal grain‐size distribution link the sand layers to the beach and thus storm‐induced overwash events. Periods with more frequent storm flooding occurred 980–1050, 1150–1300, 1450–1550, 1820–1900 and 1950–2000 ce, which is largely consistent with a positive North Atlantic Oscillation mode. The Little Ice Age (1400–1850 ce ) shows a gap of major sand layers suggesting a southward shift of storm tracks and a seasonal variance with more storm floods in spring and autumn. Warmer phases shifted winter storm tracks towards the north‐east Atlantic, indicating a possible trend for future storm‐track changes and increased storm flooding in the northern North Sea region.

Description: The seafloor morphology reflects both past and on‐going sedimentary, oceanographic and tectonic processes. Vertical movement is one of the drivers responsible for reshaping the seafloor through forming steep flanks that decrease slope stability, favour landslides, change current paths, form minibasins and control the sediment deposition, distribution and geometry. Here, we make use of these interactions to derive vertical movements and constrain the active tectonic processes at the western termination of the upper Calabrian accretionary wedge from the integrated analysis of bathymetric, backscatter, surface attributes and high‐resolution reflection seismic data. Within this area, we identify two types of deformational features and mechanisms that affect the depositional, erosional and tectonic processes at different scales. These include the deviation of channels, landslide scars, mass transport deposits (MTDs), separated drifts, sediment waves, lineaments and offset seafloor structures. The first type (long‐wavelength uplift) is an uplifted 22‐km‐wide region, in which seismic onlap relationships and the dip of deep reflectors suggest long‐lasting but slow tectonic uplift affecting sedimentation, and the second type (short‐wavelength uplift) includes three narrow elongated structures and one circular dome encircling the first region of uplift. We interpret that the first type of uplift feature was caused by tectonic deformation, while the second type is interpreted as formed by the fast uplift, tilting and faulting of modern sediments caused by diapirism due to rapid sedimentation in response to the first tectonically driven uplift. The study provides insight into the complex interaction of tectonic and sedimentary processes in the upper Calabrian accretionary wedge.

Description: Methylmercury is a potent toxin threatening the global population mainly through the consumption of marine fish. Hydrothermal venting directly delivers natural mercury to the ocean, yet its global flux remains poorly constrained. To determine the extent to which anthropogenic inputs have increased oceanic mercury levels, it is crucial to estimate natural mercury levels. Here we combine observations of vent fluids, plume waters, seawater and rock samples to quantify the release of mercury from the Trans-Atlantic Geotraverse hydrothermal vent at the Mid-Atlantic Ridge. The majority (67–95%) of the mercury enriched in the vent fluids (4,966 ± 497 pmol l −1 ) is rapidly diluted to reach background seawater levels (0.80 pmol l −1 ). A small Hg fraction (2.6–10%) is scavenged to the Trans-Atlantic Geotraverse mound rocks. Scaling up our findings and previous work, we propose a mercury flux estimate of 1.5–64.7 t per year from mid-ocean ridges. This hydrothermal flux is small in comparison to anthropogenic inputs. This suggests that most of the mercury present in the ocean must be of anthropogenic origin and that the implementation of emissions reduction measures outlined in the Minamata Convention could effectively reduce mercury levels in the global ocean and subsequently in marine fish.

Description: برونداد مدل‌های پیش‌بینی عددی وضع هوا دارای خطا است. جهت اصلاح پیش‌بینی‌های کوتاه مدت (24، 48 و 72 ساعته) دمای بیشینه و کمینه مدل WRF، از یک روش یادگیری ماشین به نام ماشین تعقیب کننده استفاده شد. در این روش با سری زمانی 300 روزه از خطای برونداد مدل و با به کارگیری روش کمترین مربعات طیفی شبه فوریه- سری زمانی، خطای پیش‌بینی‌های مدل WRF برآورد شد. خطای پیش‌بینی‌ها در دوره 01/11/2020 الی 05/03/2023 برای 560 ایستگاه هواشناسی برآورد شد. یکی از نقاط قوت این روش، استفاده از تنها یک متغیر برای کاهش خطای پیش‌بینی‌های است. عملکرد پیش‌بینی مدل WRF بسته به مکان و زمان متفاوت است مثلا نمره مهارت مدل برای دمای بیشینه در ماه سپتامبر نسبت به سایر ماه‌ها کمتر و در مناطق جنوب غربی زاگرس نسبت به سایر مناطق کمتر است، که بعد از اصلاح این وابستگی حذف، و پیش‌بینی در تمام مناطق و زمان‌ها عملکرد یکسانی دارد. نتایج نشان داد نمره مهارت، RMSE و شاخص اطمینان‌پذیری پس از اصلاح خطای مدل به شکل قابل توجهی بهبود می‌یابد. پس از اصلاح خطا، نمره مهارت مدل برای پیش‌بینی دمای بیشینه از 1/0- به 85/0 و برای دمای کمینه از 38/0 به 72/0 می‌رسد. به طور متوسط RMSE برای پیش‌بینی دمای بیشینه از 6 به 2 درجه وبرای دمای کمینه از 5/4 به 3 درجه سلسیوس می‌رسد. پس از اصلاح خطای مدل، تغییرپذیری نمره مهارت پیش‌بینی‌ها کاهش یافته و با کاهش مقدار خطای پیش‌بینی‌ها، قابلیت اطمینان‌پذیری به پیش‌بینی‌های مدل به طور متوسط از 60 درصد به 85 درصد می‌رسد.

Description: امواج درونی نقش اساسی در وضعیت هیدرولوژیکی و انرژی اقیانوس‌ها دارد یکی از انواع امواج درونی امواج بادپناه است که در اثر عبور جریان‏های زیرسطحی یا جزرومدی بر روی توپوگرافی بستر دریا به وجود می‏آیند و یکی از عوامل جابجایی لایه‏های همچگالی در زیر آب است. این موضوع باعث تغییر میزان مواد مغذی دریا و چگالی دریا خواهد شد. به همین دلیل شناخت امواج باد پناه در صنایع ماهی‏گیری و نظامی از اهمیت بالایی برخوردار است. در این مقاله با استفاده از ماژول جریان مدل سه بعدی Delft3D به صورت هیدرواستاتیک و غیرهیدرواستاتیک در تنگه هرمز که به دلیل داشتن کم‏عمقی‏های فراوان مستعد تشکیل موج بادپناه می باشد شبیه‏سازی امواج بادپناه انجام شده است و با استفاده از تصویر ماهواره‏ای SAR، داده میدانی و مطالعات پیشین اعتبارسنجی صورت گرفت. نتایج وجود امواج بادپناه در تنگه هرمز را نشان می‎دهند. هر دو مدل هیدرواستاتیک و غیرهیدرواستاتیک توانسته‏اند جهت انتشار و تولید امواج درونی را با تقریب مکانی قابل قبول شبیه‏سازی کنند، با این تفاوت که مدل غیرهیدرواستاتیک دارای مقادیر سرعت جریان بزرگتری می‏باشد، هرچند که نتایج هر دو مدل در رنج 4/0- تا 4/0+ می‏باشد. با این حال می توان گفت حالت هیدرواستاتیک تلاطم‏های بیشتری را نشان می‏دهد و به دلیل استفاده از مختصات عمودی سیگما، لایه ترموکلاین را با دقت بالاتری شبیه‏سازی می‏کند.

Description: Both aeromagnetic and radiometric data was deployed to evaluate the Curie point depth and radiogenic heat production (RHP) of the young granitic regions of Jos plateau. An area of 55 by 110 square kilometers bounded by latitude 9°30' to 10°00' N and longitude 8°30' to 9°30' E of central Nigeria. The magnetic data was subjected to spectral analysis to obtain the curie depth which was subsequently used to evaluate the geothermal gradient and Heat flow for the area. Also, the concentration of radioelements (Potassium, thorium and Uranium) and average density of the in-situ rock was used to estimate the radiogenic heat production at each point where the Curie point was evaluated. The heat flow of the study area ranges from 10 to 165.5 mW/m2 with an average value of 111.00 mW/m2. The regions with anomalous heat flow of 165.5 mW/m2 are around Bowon Dodo, Dan Tsofo, Kadunu, Gimi, Kaura and Zankan of plateau state. The geothermal gradient values range from 5 to 68 °C/Km with an average of 26.16 °C/Km. The radiometric data analysis resulted in radiogenic heat values ranging from 0.4 µWm3 to 6 µW/m3 with average radiogenic heat value of 3.36 µW/m3. Both analyses revealed that regions such as Ataka, Gimi, Jimjim and Pari could be explored for geothermal energy. The high concentration of uranium, thorium and potassium associated with the study area must have arisen from the weathered in-situ granitic basement rocks.

Description: مدل‌های گردش کلی (GCMs) کم و بیش دارای اریبی هستند و یکی از تکنیک‌های مورد استفاده برای کاهش اریبی مدل‌ها در بررسی پیامدهای تغییر اقلیم به‌کارگیری روش‌های تصحیح اریبی است. این مطالعه کارایی پنج روش تصحیح اریبی شامل دو روش نسبت‌گیری و سه روش نگاشت چندک را برای دو متغیر دمای کمینه و بیشینه در 46 ایستگاه همدید ایران طی دوره 1980-2014 با استفاده از مدل EC-Earth3-CC از سری مدل‌های CMIP6 مورد بررسی قرار می‌دهد. نتایج نشان داد برونداد مستقیم مدل EC-Earth3-CC برای هر دو متغیر دمای کمینه و بیشینه در تمامی پهنه‌های اقلیمی ایران و همچنین متوسط اقلیمی کشور دارای اریبی سرد (کم‌برآوردی) است. به‌طور کلی، پس از تصحیح اریبی، مقدار اریبی دو متغیر دمای کمینه و بیشینه به‌شکل قابل توجهی کاهش یافت. روش‌های نسبت‌گیری نسبت به روش‌های نگاشت چندک بهبود بیشتری را در برونداد مستقیم مدل نشان دادند. براساس تحلیل مقدار RMSE، روش‌های تصحیح اریبی در مقایسه با برونداد مستقیم به‌طور قابل توجهی خطا را کاهش می‌دهند. به‌طوری‌که پس از تصحیح اریبی، مقدار خطای متغیر دمای کمینه برای روش‌های نگاشت چندک تا 42 درصد و برای روش‌های نسبت‌گیری خطی و واریانس به-ترتیب 70.38 و 67.93 درصد کاهش داشته است. مقدار خطای دمای بیشینه نیز پس از تصحیح اریبی به‌ترتیب 59، 65.9 و 67.9 درصد کاهش داشته است. تصحیح اریبی سبب افزایش ضریب توافق (d) تا بیش از دو برابر در متوسط پهنه‌های اقلیمی شده‌است. به‌طور کلی روش‌های تصحیح اریبی بکارگرفته شده در این پژوهش دمای بیشینه را با دقت بالاتری نسبت به دمای کمینه برآورد می‌کنند.

Description: در این پژوهش اثر گردش بزرگ مقیاس عرض‌های میانی بر موقعیت ناوه مدیترانه برای بارش‌های فوق‌سنگین طی بازه زمانی 1979 تا 2022 بررسی شد. در این راستا با استفاده از شاخص تموج تغییرات تموج و با تحلیل همدیدی الگوی گردسی جو برای150 بارش فوق سنگین کشور تحلیل شد. نتایج نشان داد که بارش‌های فوق سنگین تحت تاثیر تقویت ناوه اطلس، گسترش جریانات از سمت اروپا و شکل‌گیری ناوه مدیترانه رخ می دهد. شکل‌گیری ناوه اطلس سبب افزایش دامنه امواج، شکل‌گیری پشته برروی اروپا و ناوه مدیترانه می شود. با شکل‌گیری این الگو، ناوه مدیترانه تغییرات طول و عرض جغرافیایی 8 درجه را نسبت به میانگین خود تجربه می‌کند. تغییرات مکانی ناوه مدیترانه به دلیل تغییرات نصف‌النهاری امواج باد غربی برروی اروپا و موقعیت ارتفاع زیاد‌ جنب‌حاره است. متغییرترین قسمت باد غربی منطبق بر بلاکینگ شرق اطلس و ناوه مدیترانه است که با تشدید شیو بین ارتفاع زیاد و کم‌ارتفاع، جریانات نصف النهاری شده و مقدار تموج افزایش‌ می‌یابد. این شرایط منجر به تقویت پشته اروپا، افزایش دامنه امواج، تکوین بندال و گسترش ناوه مدیترانه تا عرض 25 درجه می‌شود. تکوین بلاکینگ اطلس سبب تقویت پشته برروی اروپا و گسترش جریانات به سمت مدیترانه‌ می‌شود. همچنین گسترش‌ نصف‌النهاری ارتفاع زیاد اروپایی منجر به تشدید شیو فشار، شارش‌ جریانات سرد شمالی،‌ تشدید جبهه‌ز‌ایی، تعمیق ناوه مدیترانه تا دریای سرخ می شود. همزمان با تقویت ناوه مدیترانه گسترش‌ شرق‌سوی واچرخند عربستان علاوه بر اینکه منجر به گسترش‌ شرق‌سوی ناوه مدیترانه می‌شود‌، رطوبت مناسبی نیز برای رخداد بارش‌های فوق سنگین کشور تامین می‌کند.

Description: RV Meteor M197 EMS-PS ('Eastern Mediterranean Sea - Process Study'), 30.12.2023 – 06.02.2024

Description: Understanding the stress field is crucial for assessing seismic risks in Northwestern Iran, a region known for its high seismic activity and geological volatility. The intricate tectonic arrangements involving the Arabian, Anatolian, and Eurasian plates contribute to the unstable nature of the area. This study focuses on deducing stress regimes through stress inversion analysis of earthquake focal mechanisms in the North Tabriz Fault system. Analyzing the stress field is essential for understanding the elastic characteristics and geodynamics of the region. The study considers the stress field surrounding the Tabriz Fault, aiming to determine stress parameters and principal stress orientations using focal mechanisms. By analyzing 35 earthquake focal mechanism datasets from the Global Centered Moment Tensor and the Iranian Seismological Center, stress field inversions were conducted using Michael's linear inversion method and the iterative joint inversion method. The two techniques yielded distinct outcomes, with the iterative joint inversion method proving more accurate in determining stress fields and principal stress orientations. The findings indicate the existence of strike-slip faults in proximity to the North Tabriz Fault. The stress direction observed and the trajectory of the fault system suggest the influence of a transpressional mechanism. The predominant right-lateral strike-slip motion observed aligns with the prevailing tectonic regime in the region, providing evidence of strike-slip and thrust faulting stress regimes. The results contribute to a better understanding of the stress field and geodynamic situation in Northwestern Iran. They provide valuable insights for spatial analysis of future earthquakes and assessing seismic hazards in the region.

Description: کشور ایران جزو کمربند کوهزایی آلپ - هیمالیاست و به ایالت های لرزه زمین ساختی مختلفی تقسیم شده است. استان کرمان بر اساس طبقه بندی ایالت های لرزه زمین ساختی در زون ایران مرکزی قرار گرفته است. شهر هجدک نیز در ایالت لرزه زمین ساختی ایران مرکزی واقع شده است و رویداد زمین لرزه ای بزرگی را تجربه نموده است. در این تحقیق برای اولین بار شهر هجدک کرمان از نظر شرایط لرزه ای به صورت جامع مورد بررسی قرار گرفته است تا با استفاده از نتایج آن فرایند تصمیم‌گیری برای اقدامات پیشگیرانه به ویژه بهسازی و مقاوم سازی ساختمان ها در برابر زلزله در این شهر تسهیل گردد. در این تحقیق از داده های کاتالوگ زمین لرزه های موسسه ژئوفیزیک دانشگاه تهران و نقشه های زمین شناسی سازمان زمین شناسی استفاده شده است و چشمه‌های لرزه‌ای، پارامترهای لرزه‌ای، جنبش نیرومند زمین محاسبه و تحلیل خطر زلزله به روش احتمالاتی انجام شده است. بر اساس نتایج حاصل از این تحقیق، در فاصله 100 کیلومتری از محدوده شهری 6 زمین لرزه تاریخی، 4141 زمین لرزه دستگاهی با بزرگای بالای 4 از سال 1900 تا اواخر 2023 رخ داده و 8 چشمه لرزه زا از نوع ناحیه‌ای تشخیص داده شده است. ضرایب لرزه خیزی a , b محاسبه شده در این محدوده به ترتیب 86/0 و 88/3 و نرخ لرزه خیزی برای بزرگای 4 و بزرگ‌تر، 47/1 است. بیشترین شتاب سنگ کف در محدوده 45/0 است که این شتاب در محدوده شهر هجدک بین 25/0-35/0 می باشد.

Description: Phytoplankton primary productivity (PP) varies significantly over environmental gradients, particularly in physically‐dynamic systems such as estuaries and coastal seas. During summer, runoff peaks in the Changjiang River driving large environmental gradients in both the Changjiang estuary and adjacent East China Sea (ECS), likely driving significant variability in PP. As satellite models of PP often underperform in coastal waters, we aimed to develop a novel approach for assessing net PP variability in such a dynamic environment. Parallel in situ measurements of Fast Repetition Rate (FRR) fluorometry and carbon (C) uptake rates were conducted for the first time in this region during two summer cruises in 2019 and 2021. A series of 13 C‐incubations ( n = 31) were performed, with measured PP ranging from ∼6 to 1,700 mgC m −3 d −1 . Net PP values were significantly correlated with salinity ( r = 0.45), phytoplankton chlorophyll a (Chl‐ a , r = 0.88), Photosystem II (PSII) functional absorption cross‐section ( σ PSII , r = −0.76) and maximum PSII quantum yield ( F v / F m , r = 0.59). Stepwise regression analysis showed that Chl‐ a and σ PSII were the strongest predictors of net PP. A generalized additive model (GAM) was also used to estimate net PP considering nonlinear effects of Chl‐ a and σ PSII . We demonstrate that GAM outperforms linear modeling approaches in estimating net PP in this study, as evidenced by a lower root mean square error (∼140 vs. 250 mgC m −3 d −1 ). Our novel approach provides a valuable tool to examine carbon cycling dynamics in this important region. Plain Language Summary The East China Sea has a complex current system that creates a highly dynamic physical environment for phytoplankton, particularly during the summer months. Net primary productivity (PP) is highly variable in this region, yet characterizing these spatial patterns in PP is difficult due to the lack of a high‐resolution data collecting method. Therefore, a strong need exists for a quick and easily implemented method for monitoring PP in this dynamic system. Based on parallel measurements of phytoplankton biomass and photophysiology, we present a novel approach that allows us to rapidly and easily assess regional PP at a high resolution. The high data volume potentially afforded by our net PP estimation method could not only contribute to a better understanding of PP variations in such a dynamic environment, but also help fill the large gaps in field data needed for validating satellite‐based PP models. Key Points Parallel in situ measurements of net primary productivity (PP) and Fast Repetition Rate fluorometry were conducted in the Changjiang estuary Productivity was highest at stations with high Chl and low σ PSII , typically located along the Chiangjiang river plume front A generalized additive model was developed to estimate net PP, providing an approach for assessing regional C‐cycling dynamics

Description: Highlights • SPM concentration and organic fractions are analyzed in coastal-offshore gradients • Diagnostic model of SPM allows separating fresh, labile from less reactive PON • Analysis of PON fractions reveals a characteristic area, the transition zone • There, particle settling is enhanced, fostering their transport back to the coast, which controls the fate of organic matter • The transition zone is generally confined to water depths below 20 m Abstract Identifying the mechanisms that contribute to the variability of suspended particulate matter concentrations in coastal areas is important but difficult, especially due to the complexity of physical and biogeochemical interactions involved. Our study addresses this complexity and investigates changes in the horizontal spread and composition of particles, focusing on cross-coastal gradients in the southern North Sea and the English Channel. A semi-empirical model is applied on in situ data of SPM and its organic fraction to resolve the relationship between organic and inorganic suspended particles. The derived equations are applied onto remote sensing products of SPM concentration, which provide monthly synoptic maps of particulate organic matter concentrations (here, particulate organic nitrogen) at the surface together with their labile and less reactive fractions. Comparing these fractions of particulate organic matter reveals their characteristic features along the coastal-offshore gradient, with an area of increased settling rate for particles generally observed between 5 and 30 km from the coast. We identify this area as the transition zone between coastal and offshore waters with respect to particle dynamics. Presumably, in that area, the turbulence range and particle composition favor particle settling, while hydrodynamic processes tend to transport particles of the seabed back towards the coast. Bathymetry plays an important role in controlling the range of turbulent dissipation energy values in the water column, and we observe that the transition zone in the southern North Sea is generally confined to water depths below 20 m. Seasonal variations in suspended particle dynamics are linked to biological processes enhancing particle flocculation, which do not affect the location of the transition zone. We identify the criteria that allow a transition zone and discuss the cases where it is not observed in the domain. The impact of these particle dynamics on coastal carbon storage and export is discussed.

Description: The marine biological carbon pump (BCP) stores carbon in the ocean interior, isolating it from exchange with the atmosphere and thereby coregulating atmospheric carbon dioxide (CO 2 ). As the BCP commonly is equated with the flux of organic material to the ocean interior, termed “export flux,” a change in export flux is perceived to directly impact atmospheric CO 2 , and thus climate. Here, we recap how this perception contrasts with current understanding of the BCP, emphasizing the lack of a direct relationship between global export flux and atmospheric CO 2 . We argue for the use of the storage of carbon of biological origin in the ocean interior as a diagnostic that directly relates to atmospheric CO 2 , as a way forward to quantify the changes in the BCP in a changing climate. The diagnostic is conveniently applicable to both climate model data and increasingly available observational data. It can explain a seemingly paradoxical response under anthropogenic climate change: Despite a decrease in export flux, the BCP intensifies due to a longer reemergence time of biogenically stored carbon back to the ocean surface and thereby provides a negative feedback to increasing atmospheric CO 2 . This feedback is notably small compared with anthropogenic CO 2 emissions and other carbon‐climate feedbacks. In this Opinion paper, we advocate for a comprehensive view of the BCP's impact on atmospheric CO 2 , providing a prerequisite for assessing the effectiveness of marine CO 2 removal approaches that target marine biology.

Description: RV Meteor M197 EMS-PS ('Eastern Mediterranean Sea - Process Study'), 30.12.2023 – 06.02.2024

Description: Several inorganic compounds of nitrogen (N) and phosphorus (P) are key to ocean ecology because, among other effects, they sustain primary production. After discovering in the 1980s that sponges can be both source and sink of such nutrients, much has been learned, including that fluxes derive from the metabolic integration of the sponge tissues and the assemblage of prokaryotic microbes living in them (i.e., the microbiota). The advent of molecular techniques revealed exceptional phylogenetic biodiversity in the microbiota and allowed the identification of genes coding for enzymes transforming N and P compounds. However, the accumulated information remains relatively inarticulate and its ecological dimension is uncharted. Herein we summarize the basics of N and P cycling in the marine environment to further address nutrient flux rates compiled from 92 sponge species. Ammonium release or 198consumption, followed by nitrite release, emerged as the most common fluxes in sponges. Phosphate release was also prevalent. A difficulty with the available information is a bias towards tropical shallow-water demosponges and the use of non-comparable units. A total of 63 prokaryotic phyla are known from sponge microbiomes. Collectively, they have the genetic potential for all aerobic and anaerobic N transformations, facilitating the formation of closed circuits for N to recycle within the holobionts (i.e., sponge + microbiota). Often, such circuits are fueled by important production/consumption of ammonium. Phosphorus cycling remains understudied, with evidence of phosphate and (organic) phosphonate utilization. Phosphate does not appear to limit sponge microbiomes, with polyphosphate (Poly-P) probably serving more as energy storage than as a P reservoir. Dissimilatory phosphite oxidation (DPO), which would explain the phosphate efflux from the sponges, has not been detected and the causes of the efflux (perhaps anoxic Poly-P degradation) remain uncertain. A relevant benefit provided by the microbiome, in addition to recycling sponge N wastes and provisioning vitamins and some organic C and N compounds through fixation, is to serve as energetically inexpensive particulate food, liberating sponges from strict dependence on inputs of external food. To facilitate co-existence and cooperation between aerobic and anaerobic microbial lineages, sponges modulate pumping activity and have evolved special cells (bacteriocytes) to enclose microbes. Species-specific metabolic integration between sponges and their microbiome yields singular holobionts with remarkable roles in the benthic-pelagic coupling of N and P cycles. Some sponge aggregations can achieve higher denitrification rates per unit area than sediments; others have higher ammonium consumption rates than eutrophic phytoplanktonic communities. Through their microbiomes, some sponge species may also cope with low oxygen conditions and modify local N and P nutrient concentrations, unchaining a cascade of ecological changes that may lead to the exclusion of competitors. Identified gaps in knowledge related to: (i) how the nutrients going in and out of the holobiont are quantitatively connected to the microbial processes occurring inside; (ii) how microbes interact with each other; and (iii) how sponges co-evolved to facilitate co-existence and functional networking in the microbiome.

Description: The Mediterranean Sea has been sampled irregularly by research vessels in the past, mostly by national expeditions in regional waters. To monitor the hydrographic, biogeochemical and circulation changes in the Mediterranean Sea, a systematic repeat oceanographic survey programme called Med-SHIP was recommended by the Mediterranean Science Commission (CIESM) in 2011, as part of the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP). Med-SHIP consists of zonal and meridional surveys with different frequencies, where comprehensive physical and biogeochemical properties are measured with the highest international standards. The first zonal survey was done in 2011 and repeated in 2018. In addition, a network of meridional (and other key) hydrographic sections were designed: the first cycle of these sections was completed in 2016, with three cruises funded by the EU project EUROFLEETS2. This paper presents the physical and chemical data of the meridional and key transects in the Western and Eastern Mediterranean Sea collected during those cruises.

Description: Coastal German waters contain about 1.6 million tons of dumped munition, mostly left after World Wars. This study investigated the benthic macrofauna around the 'Kolberger Heide' munition dumpsite (Baltic Sea). A total of 93 macrofauna grab samples were obtained in the proximity of the munition dumpsite and in reference areas. Environmental variables analysed included the latitude/longitude, depth, terrain ruggedness, sediment grainsize distribution, TNT concentration in the bottom water and distance to the centre of munition dumpsite. The overall abundance, biomass and diversity varied among these groups, though demonstrated no clear differences regarding the proximity to munition and modelled near-bottom dissolved TNT. Among individual taxa, however, a total of 16 species demonstrated significant correlation with TNT concentration. Moreover, TNT may serve as a predictor for the distribution of three species: molluscs Retusa truncatula, Varicorbula gibba and polychaete Spio goniocephala. Possible reasons for the species distribution including their biological traits are discussed.

Description: Highlights • Global primitive arc lavas (Mg# ≥60) display notable δ49/47Ti heterogeneity. • Residual rutile imposes high δ49/47Ti of 0.24 ± 0.06 ‰ on hydrous, silicic slab melts. • Primitive Aleutian rhyodacites have the same δ49/47Ti as predicted for slab melts. • A variably diluted signature of slab melts is found in all eight subduction zones. • A slab melt component is required to generate silicic primitive arc lavas. Abstract It is still a matter of intense debate to what extent partial melting of the subducting slab contributes to arc magmatism in modern subduction zones. In particular, it is difficult to differentiate between silicate melts formed by partial melting of the slab, and aqueous fluids released during subsolidus dehydration as the main medium for slab-to-mantle wedge mass transfer. Here we use δ49/47Ti (the deviation in 49Ti/47Ti of a sample to the OL-Ti reference material) as a robust geochemical tracer of slab melting. Hydrous partial melting of subducted oceanic crust and the superjacent sedimentary layer produces silicic melts in equilibrium with residual rutile. Modelling shows that such silicic slab melts have notably higher δ49/47Ti (+0.24 ± 0.06 ‰) than their protolith due to the strong preference of rutile for the lighter isotopes of Ti. In contrast, even highly saline fluids cannot carry Ti from the slab and hence hydrous peridotite partial melts have δ49/47Ti similar to mid-ocean ridge basalts (MORB; ca. 0 ‰). Primitive (Mg# ≥60) arc lavas from eight subduction zones that are unaffected by fractional crystallisation of Fe-Ti oxides show a more than tenfold larger variation in δ49/47Ti than found in MORB. In particular, primitive arc lavas display a striking correlation between SiO2 content and δ49/47Ti that ranges from island arc basalts overlapping with MORB, to primitive rhyodacites with δ49/47Ti up to 0.26 ‰ erupted in the western Aleutian arc. The elevated δ49/47Ti of these primitive arc lavas provides conclusive evidence for partial melts of the slab as a key medium for mass transfer in subduction zones. The Aleutian rhyodacites represent a rare example of slab melts that have traversed the mantle wedge with minimal modification. More commonly, slab melts interact with the mantle wedge to form an array of primary arc magmas that are a blend of slab- and peridotite-derived melt. We identify primitive arc lavas with a clearly resolvable slab melt signature in all eight subduction zone localities, confirming that slab melting is prevalent in modern subduction zones.

Description: Highlights • An event-scale, complete lithostratigraphic column for the Miocene BFVA was created through extensive field volcanology. • Field volcanology was supplemented by volcanic glass geochemistry to separate the eruptions. • An example is presented how to undertake lithostratigraphy-based classification in poorly preserved, deeply eroded volcanic terrains. • In the ancient BFVA landscape, sea cover during eruptions and terrestrial deposition is evident. Abstract This study documents the volcanic evolution of the Miocene silicic Bükk Foreland Volcanic Area (BFVA), Northern Hungary (Central Europe) at an event-scale. The BFVA is a deeply eroded and dissected volcanic field dominated by multiple, several 10-m thick, valley-filling silicic ignimbrite units, which are chemically and texturally very similar to each other. Hence, establishing lateral correlation is a real challenge due to the sporadic and small-scale outcrops and lack of stratotypes. Detailed field observations allowed us to identify eleven lithological members including fourteen eruption events and establish a nearly complete lithostratigraphic correlation between fifteen outcrops across the BFVA. Primary pyroclastic material of each member was sampled, and volcanic glass was geochemically analyzed for major and trace element composition. The geochemical results confirm the field-based classification of the members and enable the correlation of distinct outcrops. The major and trace element composition of the glassy pyroclasts of each member of the BFVA served as basis to create a field-wide chemical reference database for regional correlational studies. Here, a new lithostratigraphic classification scheme (consisting of one lithostratigraphic formation and eleven members) is presented, which reflects the challenges unraveling the stratigraphy of ancient volcanic terrains. The field-based event-scale lithostratigraphy of the BFVA suggests a wet, partly sea-covered depositional environment in the close vicinity of the eruption centers providing favorable conditions to ‘fuel’ silicic explosive phreatomagmatism. On the contrary, paleosol horizons formed after almost each major eruption event or sequence suggests an overall near-coast terrestrial environment for the BFVA, where the emplacement of the pyroclastic material occurred.

Description: Hydrothermal fluids in ultramafic‐hosted hydrothermal systems associated with oceanic detachment faults can be more oxidizing compared to mafic‐hosted vent sites. These fluids form a mineral assemblage of pyrite, magnetite and hematite. At 13°30′N on the Mid‐Atlantic Ridge, chlorite‐quartz breccias recovered from an exposed fault scarp contain pyrite, with abundant magnetite and hematite, indicating that the redox of the fluids was variable. In primary micron‐scale zonations in pyrite, Ni, Co, and Se have a decoupled relationship, recording fluctuations in the chemical composition and temperature of hydrothermal fluid as the grains grew. Secondary zonations that erase and overprint primary zonations are limited to the grain margin and permeable regions within the grain core. Secondary zonations formed via two processes: (a) grain dissolution followed by overgrowth, and (b) remobilization of metals during oxidizing fluid flow events. In both instances, Ni and Co have been mobilized and concentrated, and are not lost to the hydrothermal fluid. Superimposed on these features is evidence of grain scale deformation related to periods of fault movement along the detachment surface. Sulfur isotope ratios (δ 34 S) in pyrite systematically decrease from the grain margin to the grain core, indicating that increased amounts of sulfur were derived from thermochemical sulfate reduction of seawater. Thus, pyrite records the evolution of fluid flow and deformation events during exhumation along the detachment surface from ∼1 to 2 km below the seafloor at the base of the lava pile, with temporal fluctuations in fluid redox identified as an important process in controlling Ni and Co enrichment in pyrite. Plain Language Summary Detachment faults are long lived faults that can expose ultramafic rocks at the seafloor. We aim to investigate the links between hydrothermal activity and detachment fault formation. To do this we use pyrite as a tape recorder for past fluid flow events. Across individual mineral grains, distinct zonations in metal content and sulfur isotope ratios show that the incursion of seawater occurred periodically during pyrite growth, increasing during fault movement events that lead to changes in the temperature and pH of the fluids in the fault zone. These changes concentrated metals toward the center of individual mineral grains. Zonations were then overprinted by later deformation‐related events, providing evidence that the samples formed at deeper crustal levels below the seafloor and were progressively exhumed at the seafloor over time. Key Points Microtextural, geochemical, and isotopic variations in subseafloor pyrite record the history of sample exhumation along a detachment fault Nickel and Co are remobilized and concentrated in pyrite across individual mineral grains in response to fluctuating fluid redox conditions Evidence of pyrite deformation and alteration mineralogy of samples indicates sample exhumation from a depth of 1–2 km

Description: Coastal upwelling areas are extraordinarily productive environments where prokaryotic communities, the principal remineralizers of dissolved organic matter (DOM), rapidly respond to phytoplankton bloom and decay dynamics. Nevertheless, the extent of variability of key microbial functions in such dynamic waters remains largely unconstrained. Our metatranscriptomics analyses of 162 marker genes encoding ecologically relevant prokaryotic functions showed distinct spatial-temporal patterns in the NW Iberian Peninsula upwelling area. Short-term (daily) changes in specific bacterial functions associated with changes in biotic and abiotic factors were superimposed on seasonal variability. Taxonomic and functional specialization of prokaryotic communities, based mostly on different resource acquisition strategies, was observed. Our results uncovered the potential influence of prokaryotic functioning on phytoplankton bloom composition and development (e.g., Cellvibrionales and Flavobacteriales increased relative gene expression related to vitamin B12 and siderophore metabolisms during Chaetoceros and Dinophyceae summer blooms). Notably, bacterial adjustments to C- or N-limitation and DMSP availability during summer phytoplankton blooms and different spatial-temporal patterns of variability in the expression of genes with different phosphate affinity indicated a complex role of resource availability in structuring bacterial communities in this upwelling system. Also, a crucial role of Cellvibrionales in the degradation of DOM (carbohydrate metabolism, TCA cycle, proteorhodopsin, ammonium, and phosphate uptake genes) during the summer phytoplankton bloom was found. Overall, this dataset revealed an intertwined mosaic of microbial interactions and nutrient utilization patterns along a spatial-temporal gradient that needs to be considered if we aim to understand the biogeochemical processes in some of the most productive ecosystems in the world´s oceans.

Description: Biological invasions pose a growing threat to ecosystems, biodiversity, and socio-economic interests. In the European Union, the introduction of non-native species through trade, tourism, and other pathways has led to unintended consequences. Among these non-native species, a subset exhibits negative impacts and is commonly referred to as ‘invasive’. However, the number of non-native species and the proportion considered invasive vary across different member states of the European Union. Classifications and definitions of invasive species also differ among countries potentially leading to an underrepresentation. Here, we use Germany as a case study to highlight gaps in invasive species classifications. The number of non-native species reported as invasive in Germany remains low (~ 14%) compared to other European Union member states (~ 22%), despite Germany’s strong economy, significant research investments, and well-established trade networks. This disparities may be attributed to complex and multifaceted factors, encompassing differences in classifications, variations in research effort and focus, and diverse national priorities. We further propose that the impacts of non-native species on resources and biodiversity may be more likely to be overlooked, principally in large economies reliant on international trade, such as Germany. This oversight could negatively affect conservation efforts and funding for research aimed at improving understanding invasive species threats. We suggest that this underreporting may stem from a focus on maintaining economic growth, which might have taken precedence over addressing the potential ecological and economic impacts of invasive species.

Description: Regime shifts in the diatom–dinoflagellate composition have occurred in the Baltic Sea (BS) and Bohai Sea (BHS) under eutrophication and have affected the entire coastal ecosystem, damaging the regulatory, provisioning, cultural, and supporting service functions of marine ecosystems. Therefore, finding a solution to restore the balance of phytoplankton community composition and mitigate eutrophication is of utmost importance. In this study, the Driver (per capita gross domestic product)-Pressure (terrestrial inputs)-State (seawater environmental parameters)-Impact (proportions of diatoms and dinoflagellates)-Response (eutrophication governance projects) framework served as a guide for our analysis of the causal relationship among various environmental components in the coastal system. The relevant data in BS and BHS spanning from the 1950s to the 2010s were collected and used to construct a diatom–dinoflagellate composition single index, which allowed us to identify the shifts in regimes (mutation points and phases) of the diatom–dinoflagellate composition and environmental factors using sequential t-test analysis. We also identified key environmental factors that moderated the diatom–dinoflagellate composition using redundancy analysis and analyzed the partial effects of the main environmental factors on the diatom–dinoflagellate composition using a generalized additive model. Finally, the regulation of the eutrophication governance investment on diatom–dinoflagellate composition was investigated. We found that (1) BS is a “time machine,” with coastal eutrophication governance and regime shift of diatom–dinoflagellate composition and environmental factors two decades earlier than that in BHS; (2) in BS, the key moderation factor of diatom proportion is SiO3-Si and those of dinoflagellates are sea surface salinity and N:P ratio; in BHS, the key moderation factors of diatom proportion are PO4-P and Si:N ratio and those of dinoflagellate are dissolved inorganic nitrogen and N:P and Si:P ratios; (3) it is projected that BHS will enter its recovery phase from eutrophication after mid-2020s. In summary, the N/P/Si stoichiometric relationships should be given greater consideration, with the exception of the “dose-response” relationship in both sea areas. Our results indicate an urgent need for an improved mechanistic understanding of how phytoplankton biodiversity changes in response to changes in nutrient load and how we should ultimately deal with the challenges that arise.

Description: The element silicon is everywhere! In fact, silicon is the second most abundant element in Earth’s crust. Silicon in rocks and minerals breaks down and is transported from rivers and streams into the world’s oceans. Many marine organisms need silicon as it is a crucial nutrient to build their skeletons. Silicon eventually reaches the seafloor, but its journey into the abyss is not straightforward due to biological, physical, and chemical processes. All these processes transport and transform silicon, creating a cycle that we call the marine silicon cycle. The silicon cycle is directly connected to the carbon cycle, making silicon a key player in the regulation of Earth’s climate. In this article, we discuss why we need to understand the marine silicon cycle, explain the steps that happen in the ocean, and demonstrate how the marine silicon cycle affects humans.

Description: There is growing concern surrounding the pervasive impacts of microplastic pollution, but despite increasing interest in this area there remains limited understanding of its disruption to biological communities and the ecosystem services they provide. One such service is the breakdown of leaf litter in freshwaters by invertebrate shredders, such as Gammarus spp., that directly and indirectly provides resources for many other species. This study investigates the effect of microplastic exposure on leaf consumption by two Gammarus species in Ireland, the native Gammarus duebeni celticus, and the invasive Gammarus pulex. Individuals were exposed to 40-48 mu m polyethylene particles for 24 h at a range of concentrations (20-200,000 MP/L), with the amount of leaf consumption in that time frame recorded. Microplastics did not affect the feeding rate of either species at environmentally relevant concentrations, indicating that ecosystem services currently provided by our study species are sustainable. However, at higher microplastic concentrations the feeding rate of G. d. celticus was significantly reduced, whereas G. pulex remained unaffected, drawing attention to species-specific and native-invader differences in microplastic impacts. The results of our study further contribute to the observed pattern that invasive species, including various amphipod species, often display a higher tolerance to environmental stressors compared to their native counterparts. This research highlights the need for mitigation of ongoing and increasing microplastic pollution that could differentially influence key ecosystem services and functions.

Description: Anthropogenic disturbances, including non-indigenous species (NIS) and climate change, have considerably affected ecosystems and socio-economies globally. Despite the widely acknowledged individual roles of NIS and global warming in biodiversity change, predicting the connection between the two still remains a fundamental challenge and requires urgent attention due to a timely importance for proper conservation management. To improve our understanding of the interaction between climate change and NIS on biological communities, we conducted laboratory experiments to test the temperature and pCO2 tolerance of four gammarid species: two native Baltic Sea species (Gammarus locusta and G. salinus), one Ponto‐Caspian NIS (Pontogammarus maeoticus) and one North American NIS (Gammarus tigrinus). Our results demonstrated that an increase in pCO2 level was not a significant driver of mortality, neither by itself nor in combination with increased temperature, for any of the tested species. However, temperature was significant, and differentially affected the tested species. The most sensitive was the native G. locusta which experienced 100% mortality at 24 °C. The second native species, G. salinus, performed better than G. locusta, but was still significantly more sensitive to temperature increase than either of the NIS. In contrast, NIS performed better than native species with warming, whereby particularly the Ponto-Caspian P. maeoticus did not demonstrate any difference in its performance between the temperature treatments. With the predicted environmental changes in the Baltic Sea, we may expect shifts in distributions of native taxa towards colder areas, while their niches might be filled by NIS, particularly those from the Ponto-Caspian region. Although, northern colder areas may be constrained by lower salinity. Additional studies are needed to confirm our findings across other NIS, habitats and regions to make more general inferences.

Description: Silicon is a crucial nutrient that can join with the element oxygen to form a substance commonly called silica. Silica, commonly known as glass, is found in rocks in the Earth’s crust and dissolves into the oceans, where organisms like algae and sponges use it to build their glassy skeletons. This process, called biosilicification, is extremely important in the silica cycle. Over time, organisms have changed the silica cycle. Today, because of these organisms, the oceans no longer contain much silica. However, when the Earth was younger and these organisms had not evolved yet, no biological processes affected silica in the oceans. The evolution of these oceanic organisms across time has removed silica from the oceans. In this article, we discuss how the evolution of silicon-using sponges, as well as tiny organisms called zooplankton and algae, have changed the amount of silica in the world’s oceans through geologic time.

Description: This study was the first to investigate the key reproductive traits of the electric lantern fish Electrona risso (Myctophidae, n = 918) and the bigscale fishes (Melamphaidae) Melamphaes polylepis (n = 260) and Scopelogadus mizolepis (n = 649). Specimens of these mesopelagic species were collected in March and April 2015 in the eastern Central Atlantic (0–24° N, 20–26° W). Sex ratio was not significantly different from 1:1 in E. risso and M. polylepis but significantly skewed toward female dominance in S. mizolepis. Reproductive phases were determined macroscopically and by histological analyses on selected individuals. Female length at 50% maturity (L50) was 55.1 mm standard length (LS) in E. risso, with an observed female maximum length (Lmax) of 81.2 mm LS. M. polylepis females had an L50 of 40.2 mm LS and an Lmax of 86.7 mm LS. S. mizolepis had an L50 of 46 mm LS and an Lmax of 97.9 mm LS. The three species show histological features of iteroparity, but the E. risso population appears to occur in two year-classes and experience only one spawning season per lifetime in the study region. All three species are batch-spawners. A batch fecundity of 2668 eggs was estimated from one E. risso individual, with a relative batch fecundity of 369 eggs g−1 gonad-free body mass. M. polylepis had a batch fecundity of 1027 eggs and a relative batch fecundity of 149 eggs g−1 (n = 3). S. polylepis had a batch fecundity of 1545 eggs and a relative batch fecundity of 215 eggs g−1 (n = 21). The median gonado-somatic index during the actively spawning phase of E. risso was 4.5, significantly lower than that of M. polylepis (7.5) and S. mizolepis (7.1). No regressing or regenerating phases were observed in this study. Batch-spawning in all three species is suggested to be advantageous to cope with intra-annual variability in food supply and other risks for offspring survival. With what appears to be in effect a (facultative) semelparous strategy in combination with a short life span in E. risso, interannual differences would have a great effect on population dynamics of this species. Knowledge is still lacking on temporal aspects of reproduction such as the duration of the spawning season and the frequency of spawning, as well as age and growth.

Description: Statistics of regional sterodynamic sea level variability are analyzed in terms of probability density functions of a 100-member ensemble of monthly mean sea surface height (SSH) timeseries simulated with the low-resolution Max Planck Institute Grand Ensemble. To analyze the impact of climate change on sea level statistics, fields of SSH variability, skewness and excess kurtosis representing the historical period 1986-2005 are compared with similar fields from projections for the period 2081-2100 under moderate (RCP4.5) and strong (RCP8.5) climate forcing conditions. Larger deviations of the models SSH statistics from Gaussian are limited to the western and eastern tropical Pacific. Under future climate warming conditions, SSH variability of the western tropical Pacific appear more Gaussian in agreement with weaker zonal easterly wind stress pulses, suggesting a reduced El Nino Southern Oscillation activity in the western warm pool region. SSH variability changes show a complex amplitude pattern with some regions becoming less variable, e.g., off the eastern coast of the north American continent, while other regions become more variable, notably the Southern Ocean. A west (decrease)-east (increase) contrast in variability changes across the subtropical Atlantic under RCP8.5 forcing is related to changes in the gyre circulation and a declining Atlantic Meridional Overturning Circulation in response to external forcing changes. In addition to global mean sea-level rise of 16 cm for RCP4.5 and 24 cm for RCP8.5, we diagnose regional changes in the tails of the probability density functions, suggesting a potential increased in variability-related extreme sea level events under global warmer conditions.

Description: Large explosive volcanic eruptions from island arcs pour pyroclastic currents into marine basins, impacting ecosystems and generating tsunamis that threaten coastal communities and infrastructures. Risk assessments require robust records of such highly hazardous events, which is challenging as most of the products lie buried under the sea. Here we report the discovery by IODP Expedition 398 of a giant rhyolitic pumice deposit emplaced 520 ± 10 ky ago at water depths of 200 to 1000 m during a high-intensity, shallow submarine eruption of ancestral Santorini Volcano. Pyroclastic currents discharged into the sea transformed into turbidity currents and slurries, forming a 〉89 ± 8 km 3 volcaniclastic megaturbidite up to 150 m thick in the surrounding marine basins, while breaching of the sea surface by the eruption column laid down veneers of ignimbrite on three islands. The eruption is one of the largest recorded on the South Aegean Volcanic Arc, and highlights the hazards from submarine explosive eruptions.

Description: RV Meteor M197 EMS-PS ('Eastern Mediterranean Sea - Process Study'), 30.12.2023 – 06.02.2024

Description: Gelatinous zooplankton are increasingly recognized to play a key role in the ocean's biological carbon pump. Appendicularians, a class of pelagic tunicates, are among the most abundant gelatinous plankton in the ocean, but it is an open question how their contribution to carbon export might change in the future. Here, we conducted an experiment with large volume in situ mesocosms (~55–60 m3 and 21 m depth) to investigate how ocean acidification (OA) extreme events affect food web structure and carbon export in a natural plankton community, particularly focusing on the keystone species Oikopleura dioica, a globally abundant appendicularian. We found a profound influence of O. dioica on vertical carbon fluxes, particularly during a short but intense bloom period in the high CO2 treatment, during which carbon export was 42%–64% higher than under ambient conditions. This elevated flux was mostly driven by an almost twofold increase in O. dioica biomass under high CO2. This rapid population increase was linked to enhanced fecundity (+20%) that likely resulted from physiological benefits of low pH conditions. The resulting competitive advantage of O. dioica resulted in enhanced grazing on phytoplankton and transfer of this consumed biomass into sinking particles. Using a simple carbon flux model for O. dioica, we estimate that high CO2 doubled the carbon flux of discarded mucous houses and fecal pellets, accounting for up to 39% of total carbon export from the ecosystem during the bloom. Considering the wide geographic distribution of O. dioica, our findings suggest that appendicularians may become an increasingly important vector of carbon export with ongoing OA.

Description: A La Niña condition in the equatorial Pacific began in the early summer of 2020 and has lasted more than two and a half years (referred to as the 2020 La Niña hereafter). Predicting its temporal evolution had attracted a lot of attention. Considering the possible phase-locked impact of the 11-year solar cycle on the tropical Pacific variability, in this study the authors present the possible modulations by the solar cycle 25 (SC25) started from December 2019, on the future temporal evolution of the 2020 La Niña. Based on statistical features of historical solar cycles, the authors propose three possible scenarios of the timing of the SC25 maximum year and discuss its possible impacts on the temporal evolution of the 2020 La Niña in the next two years. The ongoing ascending phase of SC25 dampens the development of a super El Niño condition to some extent in 2023.

Description: Seamounts are thought to function as hotspots of megafauna diversity due to their topology and environmental characteristics. However, assessments of megafauna communities inhabiting seamounts, including diversity and density, are scarce. In this study, we provide megafauna diversity and density estimates for a recently discovered, not yet characterized seamount region (Boetius seamounts) west of Cape Verde (N17° 16′, W29° 26′). We investigated the distribution of epibenthic megafauna over a large depth gradient from the seamount’s summit at 1400 m down to 3200 m water depth and provided qualitative and quantitative analyses based on quantified video data. In utilizing an ocean floor observation system (OFOS), calibrated videos were taken as a horizontal transect from the north-eastern flank of the seamount, differentiating between an upper, coral-rich region (−1354/−2358 m) and a deeper, sponge-rich region (−2358/−3218 m). Taxa were morphologically distinguished, and their diversity and densities were estimated and related to substrate types. Both the upper and deeper seamount region hosted unique communities with significantly higher megafauna richness at the seamount’s summit. Megafauna densities differed significantly between the upper (0.297 ± 0.167 Ind./m 2 ) and deeper community (0.112 ± 0.114 Ind./m). The seamount showed a vertical zonation with dense aggregations of deep-sea corals dominating the seamount’s upper region and colonies of the glass sponges Poliopogon amadou dominating the deeper region. The results are discussed in light of detected substrate preferences and co-occurrence of species and are compared with findings from other Atlantic seamounts.

Description: We, the editors of the Code4Lib Journal, sincerely apologize for the recent incident in which Personally Identifiable Information (PII) was released through the publication of an article in issue 58.

Description: RV Meteor M197 EMS-PS ('Eastern Mediterranean Sea - Process Study'), 30.12.2023 – 06.02.2024

Description: Riverine nutrient export is an important process in marine coastal biogeochemistry and also impacts global marine biology. The nitrogen cycle is a key player here. Internal feedbacks regulate not only nitrogen distribution, but also primary production and thereby oxygen concentrations. Phosphorus is another essential nutrient and interacts with the nitrogen cycle via different feedback mechanisms. After a previous study of the marine nitrogen cycle response to riverine nitrogen supply, we here additionally include phosphorus from river export with different phosphorus burial scenarios and study the impact of phosphorus alone and in combination with nitrogen in a global 3-D ocean biogeochemistry model. Again, we analyse the effects on near coastal and open ocean biogeochemistry. We find that the addition of bio-available riverine phosphorus alone or together with nitrogen affects marine biology on millennial timescales more than riverine nitrogen alone. Biogeochemical feedbacks in the marine nitrogen cycle are strongly influenced by the additional phosphorus. Where bio-available phosphorus is increased by river input, nitrogen concentrations increase as well, except for regions with high denitrification rates. High phosphorus burial rates decrease biological production significantly. Globally, riverine phosphorus leads to elevated primary production rates in the coastal and open oceans.

Description: Dieser Policy Brief beruht auf den Factsheets der Forschungsmission CDRmare der Deutschen Allianz Meeresforschung (DAM), die vom Bundesministerium für Bildung und Forschung (BMBF) und den norddeutschen Bundesländern gefördert wird. In diesem Policy Brief betrachten wir die marine Kohlendioxid-Abscheidung und -Speicherung (Carbon Capture and Storage, CCS). Version 2

Description: The Agulhas Leakage (AL) transports warm and salty Indian Ocean waters into the Atlantic Ocean and as such is an important component of the global ocean circulation. These waters are part of the upper limb of the Atlantic Meridional Overturning Circulation (AMOC) and AL variability has been linked to AMOC variability. The AL is expected to increase under a warming climate due to a shift in the Southern Hemisphere westerlies, which could further influence the AMOC dynamics. This study investigates the AL transport variability on long time scales in the pre-industrial and under a warming climate and its relation to the AMOC. It uses a high-resolution configuration of the Community Earth System Model (CESM) with a nominal horizontal resolution of 0.1° for the ocean and sea-ice and 0.25° for the atmosphere and land, which resolves the necessary spatial scales. The simulated AL transport of 19.7 ± 3 Sv lies well within the observed range of 21.3 ± 4.7 Sv. A positive correlation between the Agulhas Current and the AL is shown, meaning that an increase of the Agulhas Current transport leads to an increase in AL. Furthermore, the salt flux associated with the AL influences AMOC dynamics through the salt-advection feedback by reducing the AMOC’s freshwater transport at 34°S. In a warming climate, the AL transport was indeed found to increase due to strengthened and southward shifting winds while the Agulhas Current transport was found to decrease. Consequently, a larger fraction of the Agulhas Current will flow into the Atlantic Ocean rather than being recirculated into the Indian Ocean. The increase in AL is accompanied by a higher salt flux into the Atlantic Ocean, which destabilises the AMOC within the salt-advection-feedback. But whether and to what extent this additional salt advected to the North Atlantic could also dampen an AMOC weakening induced by increased meltwater input under climate change still needs further research.

Description: RUMMs is a tool for explosive ordnance disposal (EOD) risk assessment (RA). It uses 34 factors of unexploded ordnance (UXO) and the environment in which EOD takes place, RUMMs calculates three output values: the Probability of an Undesired Detonation, the Consequence of an Undesired Detonation, and the Complexity of the EOD Operation.

Description: Highlights: • Change in sea urchin species composition from RBC and NRBC habitats. • Sand coverage is an important factor that influences the sea urchin species composition. • The relationship between sea urchins and their habitat is species-specific. Sea urchins are important components of marine ecosystems and can act as bioindicators, reflecting the health of reefs. The spatial patterns of sea urchins are largely shaped by the type of habitat. In Hong Kong, coral communities are divided into two distinct types: reef -building coral habitats and non -reef -building coral habitats. In summer 2020, a qualitative survey was conducted using SCUBA at 56 sites across eastern and western waters, recording a total of 11 species from 6 families of sea urchins. Out of these 56 sites, 14 were selected for a quantitative survey to investigate the relationship between sea urchin assemblages and the two types of coral habitat. We found that the species composition of sea urchins differed significantly between the two habitats, and the presence of sand was a critical factor influencing the species composition of sea urchins. Sand coverage had a positive effect on Salmasic sphaeroides abundance but a negative effect on the abundance of Diadema setosum and Heliocidaris crassispina. The distribution of sea urchins across different degrees of sand coverage may be associated with food availability or species -specific adaptive behaviour, likely due to niche preferences.

Description: Highlights • East Asian climate evolution was dependent on the latitude of the proto-Tibetan Plateau in the deep past; • Global warming induced wetting at mid-latitude East Asian in the mid-Cretaceous; • The proto-Tibetan Plateau uplift led to drying in the subtropical East Asian in the mid-Cretaceous. Abstract Sedimentary records indicate that subtropical and mid-latitude East Asia exhibited considerable drying and wetting, respectively, during the mid-Cretaceous, which is considered to be relevant to much higher atmospheric carbon dioxide (pCO2) concentrations and/or proto-Tibetan Plateau (proto-TP) uplift. In order to explore and compare their roles on the East Asian climate evolution, we conducted simulations of the mid-Cretaceous climate system with different atmospheric pCO2 levels and varying topographies. The results show that both factors had significant influences on the East Asian climate. As the increase in atmospheric pCO2 levels from ∼560–1120 ppmv to ∼1120–2240 ppmv, the precipitation increases considerably over mid-latitude East Asia, but only small changes in the subtropical portion of East Asia occur. Simultaneously, the effects of the proto-TP uplift are opposite to those of global warming trend during that period. Generally, it leads to a precipitation decrease over subtropical East Asia, but rather minor changes over mid-latitude East Asia. These changes are qualitatively consistent with the deduction based on the geological records, but the magnitudes of the modeled precipitation changes are relatively smaller. Therefore, we can conclude that the subtropical East Asian drying during the mid-Cretaceous can be partly explained by the proto-TP uplift, while the mid-latitude East Asian wetting was partly due to global warming. However, additional factor(s) also played a significant role in the East Asian climate evolution during the mid-Cretaceous.

Description: Catania (09.02.24) – Catania (22.02.24), MIDES - Measuring and Imaging Deformation of Etna’s Submerged unstable flank

Description: Carbon dioxide removal (CDR) – the creation, enhancement, and upscaling of carbon sinks – has become a pillar of national and corporate commitments towards Net Zero emissions, as well as pathways towards realizing the Paris Agreement's ambitious temperature targets. In this perspective, we explore CDR as an emerging issue of Earth System Governance (ESG). We draw on the results of a workshop at the 2022 Earth System Governance conference that mapped a range of actors, activities, and issues relevant to carbon removal, and refined them into research questions spanning four intersecting areas: modeling and systems assessment, societal appraisal, policy, and innovation and industry. We filter these questions through the five lenses of the ESG framework and highlight several key ‘cross-cutting’ issues that could form the basis of an integrated ESG research agenda on CDR.

Description: Highlights • Cu complexation was measured for the first time in the Fram Strait region. • Cu-binding ligand concentrations and binding strength varied longitudinally in the Fram Strait. • More than 99 % of dCu was organically complexed by strong ligands. • On the Greenland shelf the Transpolar Drift and the coastal processes were the main sources of Cu ligands. Abstract The Fram Strait represents the major gateway of Arctic Ocean waters towards the Nordic Seas and North Atlantic Ocean and is a key region to study the impact of climate change on biogeochemical cycles. In the region, information about trace metal speciation, such as copper, is scarce. This manuscript presents the concentrations and conditional stability constants of copper-binding ligands (LCu and log KcondCu2+L) in the water column of Fram Strait and the Greenland shelf (GEOTRACES cruise GN05). Cu-binding ligands were analysed by Competitive Ligand Exchange-Adsorptive Cathodic Stripping Voltammetry (CLE-ACSV) using salicylaldoxime (SA) as competitive ligand. Based on water masses and the hydrodynamic influences, three provinces were considered (coast, shelf, and Fram Strait) and differences were observed between regions and water masses. The strongest variability was observed in surface waters, with increasing LCu concentrations (mean values: Fram Strait = 2.6 ± 1.0 nM; shelf = 5.2 ± 1.3 nM; coast = 6.4 ± 0.8 nM) and decreasing log KcondCu2+L values (mean values: Fram Strait = 15.7 ± 0.3; shelf = 15.2 ± 0.3; coast = 14.8 ± 0.3) towards the west. The surface LCu concentrations obtained above the Greenland shelf indicate a supply from the coastal environment to the Polar Surface Water (PSW) which is an addition to the ligand exported from the central Arctic to Fram Strait. The significant differences (in terms of LCu and log KcondCu2+L) between shelf and coastal samples were explained considering the processes which modify ligand concentrations and binding strengths, such as biological activity in sea-ice, phytoplankton bloom in surface waters, bacterial degradation, and meltwater discharge from 79NG glacier terminus. Overall, the ligand concentration exceeded those of dissolved Cu (dCu) and kept the free copper (Cu2+) concentrations at femtomolar levels (0.13–21.13 fM). This indicates that Cu2+ toxicity limits were not reached and dCu levels were stabilized in surface waters by organic complexes, which favoured its transport to the Nordic Seas and North Atlantic Ocean and the development of microorganism.

Description: The southeastern tropical Atlantic hosts a coastal upwelling system characterized by high biological productivity. Three subregions can be distinguished based on differences in the physical climate: the tropical Angolan and the northern and southern Benguela upwelling systems (tAUS, nBUS, sBUS). The tAUS, which is remotely forced via equatorial and coastal trapped waves, can be characterized as a mixing-driven system, where the wind forcing plays only a secondary role. The nBUS and sBUS are both forced by alongshore winds and offshore cyclonic wind stress curl. While the nBUS is a permanent upwelling system, the sBUS is impacted by the seasonal cycle of alongshore winds. Interannual variability in the region is dominated by Benguela Niños and Niñas that are warm and cold events observed every few years in the tAUS and nBUS. Decadal and multidecadal variations are reported for sea surface temperature and salinity, stratification and subsurface oxygen. Future climate warming is likely associated with a southward shift of the South Atlantic wind system. While the mixing-driven tAUS will most likely be affected by warming and increasing stratification, the nBUS and sBUS will be mostly affected by wind changes with increasing winds in the sBUS and weakening winds in the northern nBUS.

Description: RV MARIA S. MERIAN MSM126 “Jellyweb Madeira” 9. Februar – 4. März 2024 1. Wochenbericht (9.-11. Februar, 2024)

Description: The increasing global demand for seafood, coupled with the limitations of current fish stocks and aquaculture practices, requires the development of sustainable aquaculture solutions. In this context, this study explores the potential of a novel cage technology - Flow2Vortex - for the cultivation of jellyfish, a low-trophic-level organism with increasing market demand. The unique cage design creates a laminar and circular water flow, providing optimal conditions for cultivating fragile planktonic species. Indoor experiments demonstrated the successful growth of jellyfish in the cage, with growth rates of up to 11.6% per day. In addition, field tests in open waters confirmed the cage's ability to maintain a diffuse and controlled flow inside, even under strong external currents. The cage also maintained significantly higher zooplankton concentrations than the surrounding environment, offering a consistent food source for the cultivated jellyfish. These findings highlight the potential of the Flow2Vortex cage for scalable indoor and outdoor cultivation of low-trophic-level organisms, such as jellyfish, contributing to the diversification and sustainability of aquaculture practices.

Description: Catania (09.02.24) – Catania (22.02.24), MIDES - Measuring and Imaging Deformation of Etna’s Submerged unstable flank

Description: 〈p〉〈em〉The COVID-19 pandemic has underscored the necessity for digital infrastructure and accessibility, particularly in the education sector. This paper investigates the benefits and effectiveness of utilizing Green Cloud Computing (GCC) techniques for the dissemination of educational library data in remote regions of India during this critical period. The GCC model, known for its energy efficiency and reduced environmental impact, is proposed as a robust, scalable, and eco-friendly solution for providing remote educational access. The research utilizes a mixed-methods approach, incorporating both quantitative assessments of data reach and usage, and qualitative surveys to understand user experiences. The study reveals that GCC techniques can significantly improve educational resource distribution, thereby mitigating the educational disparities further exacerbated by the pandemic. These findings reinforce the potential of GCC techniques as a sustainable and inclusive technology in reshaping the educational landscape in remote regions.〈/em〉〈/p〉

Description: 〈p〉〈em〉One of the most crucial global issues of our era is climate change, whose consequences are presently being felt all over the world. As climate change keeps on forgoing, it's important that governments, organizations, and businesses take visionary actions for adapting and protecting themselves from calamities.〈/em〉〈em〉 This paper summarizes the application of Remote Sensing (RS) and 〈/em〉〈em〉Geographic Information System (〈/em〉〈em〉GIS) in observing impact of climate change on drought, soil moisture, land degradation, food security, EHIs’ characterization and blue carbon science and review of AI based climate solutions. The〈/em〉〈em〉 〈/em〉〈em〉integration of advanced machine learning algorithms,〈/em〉〈em〉 〈/em〉〈em〉real-time data analysis, and other cutting-edge technologies could lead to even more effective climate change〈/em〉〈em〉 〈/em〉〈em〉adaptation strategies. AI-activated climate change adaptation strategies have the prospective to significantly〈/em〉〈em〉 〈/em〉〈em〉improve the resilience of infrastructure communities, and businesses to the changing climate.〈/em〉〈strong〉〈/strong〉〈/p〉

Description: RV MARIA S. MERIAN MSM126 “Jellyweb Madeira” 9. Februar – 4. März 2024 2.Wochenbericht (12. – 18. Februar 2024)

Description: Highlights • More diverse non-native taxa generally include more economically costly species. • Chordates, nematodes and pathogens are among significantly over-represented taxa. • Monetary cost magnitude links positively to numbers of costly invasive species. • Costs are biased towards a few ‘hyper-costly’ invasive species groups. • Future invasion rates will continue to harbour new economically costly species. Abstract A dominant syndrome of the Anthropocene is the rapid worldwide spread of invasive species with devastating environmental and socio-economic impacts. However, the dynamics underlying the impacts of biological invasions remain contested. A hypothesis posits that the richness of impactful invasive species increases proportionally with the richness of non-native species more generally. A competing hypothesis suggests that certain species features disproportionately enhance the chances of non-native species becoming impactful, causing invasive species to arise disproportionately relative to the numbers of non-native species. We test whether invasive species with reported monetary costs reflect global numbers of established non-native species among phyla, classes, and families. Our results reveal that numbers of invasive species with economic costs largely reflect non-native species richness among taxa (i.e., in 96 % of families). However, a few costly taxa were over- and under-represented, and their composition differed among environments and regions. Chordates, nematodes, and pathogenic groups tended to be the most over-represented phyla with reported monetary costs, with mammals, insects, fungi, roundworms, and medically-important microorganisms being over-represented classes. Numbers of costly invasive species increased significantly with non-native richness per taxon, while monetary cost magnitudes at the family level were also significantly related to costly invasive species richness. Costs were biased towards a few ‘hyper-costly’ taxa (such as termites, mosquitoes, cats, weevils, rodents, ants, and asters). Ordination analysis revealed significant dissimilarity between non-native and costly invasive taxon assemblages. These results highlight taxonomic groups which harbour disproportionately high numbers of costly invasive species and monetary cost magnitudes. Collectively, our findings support prevention of arrival and containment of spread of non-native species as a whole through effective strategies for mitigation of the rapidly amplifying impacts of invasive species. Yet, the hyper- costly taxa identified here should receive greater focus from managers to reduce impacts of current invasive species.

Description: The coastal ocean contributes to regulating atmospheric greenhouse gas concentrations by taking up carbon dioxide (CO2) and releasing nitrous oxide (N2O) and methane (CH4). In this second phase of the Regional Carbon Cycle Assessment and Processes (RECCAP2), we quantify global coastal ocean fluxes of CO2, N2O and CH4 using an ensemble of global gap-filled observation-based products and ocean biogeochemical models. The global coastal ocean is a net sink of CO2 in both observational products and models, but the magnitude of the median net global coastal uptake is similar to 60% larger in models (-0.72 vs. -0.44 PgC year-1, 1998-2018, coastal ocean extending to 300 km offshore or 1,000 m isobath with area of 77 million km2). We attribute most of this model-product difference to the seasonality in sea surface CO2 partial pressure at mid- and high-latitudes, where models simulate stronger winter CO2 uptake. The coastal ocean CO2 sink has increased in the past decades but the available time-resolving observation-based products and models show large discrepancies in the magnitude of this increase. The global coastal ocean is a major source of N2O (+0.70 PgCO2-e year-1 in observational product and +0.54 PgCO2-e year-1 in model median) and CH4 (+0.21 PgCO2-e year-1 in observational product), which offsets a substantial proportion of the coastal CO2 uptake in the net radiative balance (30%-60% in CO2-equivalents), highlighting the importance of considering the three greenhouse gases when examining the influence of the coastal ocean on climate. The coastal ocean regulates greenhouse gases. It acts as a sink of carbon dioxide (CO2) but also releases nitrous oxide (N2O) and methane (CH4) into the atmosphere. This synthesis contributes to the second phase of the Regional Carbon Cycle Assessment and Processes (RECCAP2) and provides a comprehensive view of the coastal air-sea fluxes of these three greenhouse gases at the global scale. We use a multi-faceted approach combining gap-filled observation-based products and ocean biogeochemical models. We show that the global coastal ocean is a net sink of CO2 in both observational products and models, but the coastal uptake of CO2 is similar to 60% larger in models than in observation-based products due to model-product differences in seasonality. The coastal CO2 sink is strengthening but the magnitude of this strengthening is poorly constrained. We also find that the coastal emissions of N2O and CH4 counteract a substantial part of the effect of coastal CO2 uptake in the atmospheric radiative balance (by 30%-60% in CO2-equivalents), highlighting the need to consider these three gases together to understand the influence of the coastal ocean on climate. We synthesize air-sea fluxes of CO2, nitrous oxide and methane in the global coastal ocean using observation-based products and ocean models The coastal ocean CO2 sink is 60% larger in ocean models than in observation-based products due to systematic differences in seasonality Coastal nitrous oxide and methane emissions offset 30%-60% of the CO2 coastal uptake in the net radiative balance

Description: 〈p〉〈em〉Urban transportation systems face significant challenges due to rapid population growth and development. This study delves into the enhancement of road safety in Navi Mumbai by employing Geographic Information System (GIS) and Remote Sensing (RS) techniques. The escalating rate of vehicular accidents in Navi Mumbai presents a pressing concern. This research investigates accident data and traffic patterns, identifying vulnerable areas prone to accidents and congestion. By conducting spatial analysis using GIS and RS, the study aims to uncover accident hotspots and traffic congestion zones, offering insights into underlying road safety issues. The research methodology involves a multi-stage process. Initial data collection from various sources, including police reports, live traffic data, and satellite imagery, forms the foundation. Geographic coordinates extracted and processed through GIS applications aid in plotting accident locations and creating density maps. Additionally, on-site investigations at strategically chosen locations provide invaluable insights into local conditions, traffic patterns, and contributing factors to congestion and accidents. The findings are presenting tailored solutions for each area, ranging from optimized traffic signal timings to infrastructural improvements. The findings of this study present actionable insights aimed at improving road safety and traffic management in Navi Mumbai. Recommendations encompassing signal optimizations, infrastructure enhancements, and community engagement strategies offer a holistic approach to mitigate traffic congestion and reduce accidents. The collaborative effort with relevant authorities, as highlighted in the study, serves as a crucial step towards implementing these recommendations for meaningful change. This research not only identifies critical areas for intervention but also serves as a model for leveraging GIS and RS techniques to enhance the road safety in urban areas, paving the way for safer and efficient transportation networks in the future.〈/em〉〈/p〉

Description: Highlights: • Ca. 418 ka Pauzhetka tephra from South Kamchatka was found in 11 marine sediment cores. • New major and trace element analyses allow identification of tephra glasses. • K/Ti and K/Fe maxima mark the Pauzhetka tephra presence in marine sediments. • The tephra occurs at Marine Isotope Stages 12 to 11c and below the Bermuda excursion. • The revised ash dispersal covers vast areas in the NW Pacific and Okhotsk Sea. Abstract: The distal Pauzhetka tephra, formed by a large caldera-forming volcanic eruption in South Kamchatka, has been identified in eleven recently recovered marine sediment cores based on major and trace element compositions of tephra glass. Ten SO264 cores form a transect along the Emperor Seamount Chain (ESC) in the Northwest (NW) Pacific between ∼50.3° and ∼45°N, 800–1200 km southeast of the Pauzhetka caldera. One additional core LV28-41-4 was retrieved in the Okhotsk Sea, ∼600 km west of the caldera. The Pauzhetka tephra glass shards have a characteristic medium-K rhyolite composition and trace element content compatible with the rear-arc position of the source volcano that ensures their identification. In the NW Pacific SO264 cores, the tephra is preserved as layers in cores 33, 47, 49, 53, 55, 56 and 62, as a lens in core 45, and as cryptotephra in cores 57 and 66. It forms a cryptotephra in the Okhotsk Sea core LV28-41-4. Distinctively high XRF-retrieved K/Ti and K/Fe ratios compared to those for the host sediments help identify the Pauzhetka tephra. According to our refined stable oxygen isotope (δ18O)- and magneto-stratigraphy of two studied and two reference cores, the Pauzhetka tephra occurs within a local δ18O maximum during a transition from marine isotope stage 12 to 11c (Termination V) and below a paleointensity minimum referred to as the Bermuda excursion, at ca. 418 ka. Using the tephra age as an isochron, we show that average linear sedimentation rates decrease southward along a transect of the SO264 cores, except in core 55. It partially reflects an intensification of mid-depth currents causing winnowing, erosion or non-deposition along the ESC over the past 418 kyr. An increased linear sedimentation rate in core 55, recovered from the southern leeward side of the Minnetonka Seamount, appears to record the pelagic accumulation protected from the mid-depth current influence. Our findings expand the former ash dispersal area farther southeast in the NW Pacific and southwest in the Okhotsk Sea. The new data on the tephra thickness supports the axis direction of the fallout zone southeast of the Pauzhetka caldera. Our results suggest the Pauzhetka tephra as a key middle Pleistocene isochron for the stratigraphy and correlation of the NW Pacific and Okhotsk Sea sediments.

Description: Three boreholes drilled during the International Ocean Discovery Program (IODP) Expedition 396 have yielded unexpected findings of altered granitic rocks covered by basalt flows, interbedded sediments and glacial mud near the continent‐ocean transition of the mid‐Norwegian margin. U‐Pb and K‐Ar geochronological analyses were conducted on both protolithic and authigenically formed K‐bearing minerals to determine the age of granite crystallisation and subsequent alteration episodes. The granite's crystallisation age based on 104 zircons is 56.3 ± 0.2 Ma, and subsequent exhumation along with alteration/weathering events took place between 54.7 ± 1 and 37.1 ± 1 Ma. This intrusion represents the youngest granite discovered in Norway and intruded at an extremely shallow crustal level before a rapid rift‐to‐drift transition. The shallow emplacement of granitic rock and its fast exhumation before and during the onset of volcanism holds significant implications for the syn‐ and post‐breakup tectonic evolution of volcanic margins.

Description: The past ∼200 million years of Earth's geomagnetic field behavior have been recorded within oceanic basalts, many of which are only accessible via scientific ocean drilling. Obtaining the best possible paleomagnetic measurements from such valuable samples requires an a priori understanding of their magnetic mineralogies when choosing the most appropriate protocol for stepwise demagnetization experiments (either alternating field or thermal). Here, we present a quick, and non‐destructive method that utilizes the amplitude‐dependence of magnetic susceptibility to screen submarine basalts prior to choosing a demagnetization protocol, whenever conducting a pilot study or other detailed rock‐magnetic characterization is not possible. We demonstrate this method using samples acquired during International Ocean Discovery Program Expedition 391. Our approach is rooted in the observation that amplitude‐dependent magnetic susceptibility is observed in basalt samples whose dominant magnetic carrier is multidomain titanomagnetite (∼TM 60–65 , (Ti 0.60–0.65 Fe 0.35–0.40 )Fe 2 O 4 ). Samples with low Ti contents within titanomagnetite or samples that have experienced a high degree of oxidative weathering do not display appreciable amplitude dependence. Due to their low Curie temperatures, basalts that possess amplitude‐dependence should ideally be demagnetized either using alternating fields or via finely‐spaced thermal demagnetization heating steps below 300°C. Our screening method can enhance the success rate of paleomagnetic studies of oceanic basalt samples. Plain Language Summary Oceanic basalts are ideal recorders of the Earth's magnetic field. To decipher magnetic histories recorded in rocks, paleomagnetists need to isolate the magnetization directions and intensities within rocks by one of two possible methods. One method typically involves progressively heating the samples to high temperatures. The other method involves exposing samples to alternating magnetic fields with increasing peak field intensities. Both of these methods are ultimately destructive to the original magnetization preserved within rocks. However, without knowledge of a given rock's magnetic mineralogy, randomly choosing thermal or alternating field demagnetization methods may result in high failure rates. We developed a pre‐screening method to help decide which cleaning method will likely be more successful for a given sample based on low‐field magnetic susceptibility measurements. These measurements do not affect the original magnetic information recorded in a rock, thereby permitting subsequent paleomagnetic studies on the same sample. Our technique can be performed as rapidly as 2 min per sample, is non‐destructive, and does not require complicated sample preparation. Key Points Paleomagnetic studies utilize either alternating field or thermal demagnetization, but it is difficult to choose the best protocol a priori Amplitude‐dependence of magnetic susceptibility measurements permits preliminary magnetic mineralogy characterization in submarine basalts Rapid amplitude‐dependence measurements may aid in deciding upon the best demagnetization protocol for submarine basalt samples

Description: Octocorals (Cnidaria: Anthozoa) have a global distribution and form benthic assemblages along the depth gradient, from shallow to deep waters. They often occur below SCUBA diving limits, where they can become dominant habitat builders and aggregate different taxa. During a cruise in February 2023, one octocoral specimen was collected at 1453 m depth at Kebrit Deep, in the northern Saudi Arabian Red Sea axis, an area with extremely high temperature and salinity profiles at depth. Morphological analysis coupled with DNA barcoding using two mitochondrial markers ( COI and mtMuts ), revealed that the coral belongs to Acanthogorgia , a genus of azooxanthellate octocorals known to occur from 3 to 2300 m depths in cold, temperate and tropical waters. In the Red Sea, the genus was previously only known from shallower waters. Hence, we report the deepest record of the genus Acanthogorgia from the warm and saline Red Sea basin. This finding provides novel insights on deep-water octocoral diversity in the Red Sea, a still scantily explored area of the world, while emphasizing the need for further explorations at depth.

Description: Key Points: - Freshwater input has significantly contributed to the surface warming at the peak of the 1995 Benguela Niño - Anomalously high river discharge and precipitation increased stratification and reduced turbulent heat loss by creating barrier layers - Combination of high freshwater input and strong poleward surface current might play a role in temperature variability off Angola Benguela Nino events are characterized by strong warm sea surface temperature (SST) anomalies off the Angolan and Namibian coasts. In 1995, the strongest event in the satellite era took place, impacting fish availability in both Angolan and Namibian waters. In this study, we use direct observations, satellite data, and reanalysis products to investigate the impact that the up-until-now unnoticed mechanism of freshwater input from Congo River discharge (CRD) and precipitation had on the evolution of the 1995 Benguela Nino. In the onset phase of the event, anomalous rainfall in November/December 1994 at around 6 degrees S, combined with a high CRD, generated a low salinity plume. The plume was advected into the Angola-Namibia region in the following February/March 1995 by an anomalously strong poleward surface current generated by the relaxation of the southerly winds and shifts in the coastal wind stress curl. The presence of this low surface salinity anomaly of about -2 psu increased ocean stability by generating barrier layers, thereby reducing the turbulent heat loss, since turbulent mixing acted on a weak vertical temperature gradient. A mixed layer heat budget analysis demonstrates that southward advection of Angolan waters drove the warming at the onset, while reduced mixing played the main role at the event's peak. We conclude that a freshwater input contributed to the SST increase in this exceptionally strong event and suggest that this input can influence the SST variability in Angola-Namibia waters through a combination of high CRD, precipitation, and the presence of a strong poleward surface current. Benguela Nino events are characterized by excessive warming of the sea surface temperature off the Angolan and Namibian coasts. One of the strongest-ever recorded warm events dates back to 1995, impacting fish availability in both Angolan and Namibian waters. In our research, we investigate if freshwater from rain and from the Congo River could have impacted the evolution of this 1995 Benguela Nino. In the event's early stage, high precipitation and river discharge generated a low salinity pool at the Congo River mouth, which in February/March 1995 was taken to the south by an exceptionally strong surface current, generated by changes in wind strength and direction at the African coast. This low sea surface salinity in a shallow layer in the upper meters of the ocean increased the ocean's stability. As the stabilized waters diminished the usual mixing from the depths below which cools down the surface waters, it contributed to an increase in warming in the surface layer of the ocean. We conclude that the warming of the surface waters in the region was indeed influenced by the combination of high precipitation and high Congo River discharge with a strong surface current toward the south. Freshwater input has significantly contributed to the surface warming at the peak of the 1995 Benguela Nino Anomalously high river discharge and precipitation increased stratification and reduced turbulent heat loss by creating barrier layers Combination of high freshwater input and strong poleward surface current might play a role in temperature variability off Angola

Description: Iodine cycling in the ocean is closely linked to productivity, organic carbon export, and oxygenation. However, iodine sources and sinks at the seafloor are poorly constrained, which limits the applicability of iodine as a biogeochemical tracer. We present pore water and solid phase iodine data for sediment cores from the Peruvian continental margin, which cover a range of bottom water oxygen concentrations, organic carbon rain rates and sedimentation rates. By applying a numerical reaction‐transport model, we evaluate how these parameters determine benthic iodine fluxes and sedimentary iodine‐to‐organic carbon ratios (I:C org ) in the paleo‐record. Iodine is delivered to the sediment with organic material and released into the pore water as iodide (I − ) during early diagenesis. Under anoxic conditions in the bottom water, most of the iodine delivered is recycled, which can explain the presence of excess dissolved iodine in near‐shore anoxic seawater. According to our model, the benthic I − efflux in anoxic areas is mainly determined by the organic carbon rain rate. Under oxic conditions, pore water dissolved I − is oxidized and precipitated at the sediment surface. Much of the precipitated iodine re‐dissolves during early diagenesis and only a fraction is buried. Particulate iodine burial efficiency and I:C org burial ratios do increase with bottom water oxygen. However, multiple combinations of bottom water oxygen, organic carbon rain rate and sedimentation rate can lead to identical I:C org , which limits the utility of I:C org as a quantitative oxygenation proxy. Our findings may help to better constrain the ocean's iodine mass balance, both today and in the geological past. Key Points The impact of early diagenesis on benthic iodine fluxes and iodine burial was quantitatively evaluated using a reaction‐transport model Dissolved iodine anomalies in the water column are indicative of benthic efflux from anoxic sediments with high organic carbon turnover Not only bottom water oxygen but also organic carbon delivery and sedimentation rate determine sedimentary iodine‐to‐organic carbon ratios

Description: The understanding of silicate weathering and its role as a sink for atmospheric CO 2 is important to get a better insight into how the Earth shifts from warm to cool climates. The lithium isotope composition (δ 7 Li) of marine carbonates can be used as a proxy to track the past chemical weathering of silicates. A high‐resolution δ 7 Li record would be helpful to evaluate the role of silicate weathering during the late Cretaceous climate cooling. Here, we assess chalk as a potential archive for reconstructing Late Cretaceous seawater Li isotope composition by comparing Maastrichtian chalk from Northern Germany (Hemmoor, Kronsmoor) to a Quaternary coccolith ooze from the Manihiki Plateau (Pacific Ocean) as a lithological analog to modern conditions. We observe a negative offset of 3.9 ± 0.6‰ for the coccolith ooze relative to the modern seawater Li isotope composition (+31.1 ± 0.3‰; 2SE; n = 54), a value that falls in the range of published offsets for modern core‐top samples and for brachiopod calcite. Further, the negative offset between the Li isotope compositions of Manihiki coccolith ooze and modern planktonic foraminifera is 2.3 ± 0.6‰. Although chalk represents a diagenetically altered modification of pelagic nannofossil ooze, manifested by changes in the composition of trace elements, we observe a consistent offset of Li isotope data between Maastrichtian chalk and Maastrichtian planktonic foraminiferal data (−1.4 ± 0. 5‰) that lies within the uncertainty of modern values. We therefore suggest that chalk can be used as a reliable archive for δ 7 Li reconstructions. Key Points Chalk is a reliable archive for the Li isotope composition of seawater Coccolith ooze has a negative offset of 3.9 ± 0.6‰ from modern seawater for Li isotope ratios The estimated mean value for the late Maastrichtian seawater Li isotope composition is +27.5 ± 1.0‰