ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • American Institute of Physics
  • Institute of Electrical and Electronics Engineers (IEEE)
  • Springer Science + Business Media
  • Wiley
  • 2020-2024  (826)
  • 2005-2009
  • 1990-1994
  • 2023  (166)
  • 2021  (660)
Collection
Years
Year
  • 1
    Publication Date: 2023-06-21
    Description: The calving of A-68, the 5,800-km2, 1-trillion-ton iceberg shed from the Larsen C Ice Shelf in July 2017, is one of over 10 significant ice-shelf loss events in the past few decades resulting from rapid warming around the Antarctic Peninsula. The rapid thinning, retreat, and collapse of ice shelves along the Antarctic Peninsula are harbingers of warming effects around the entire continent. Ice shelves cover more than 1.5 million km2 and fringe 75% of Antarctica's coastline, delineating the primary connections between the Antarctic continent, the continental ice, and the Southern Ocean. Changes in Antarctic ice shelves bring dramatic and large-scale modifications to Southern Ocean ecosystems and continental ice movements, with global-scale implications. The thinning and rate of future ice-shelf demise is notoriously unpredictable, but models suggest increased shelf-melt and calving will become more common. To date, little is known about sub-ice-shelf ecosystems, and our understanding of ecosystem change following collapse and calving is predominantly based on responsive science once collapses have occurred. In this review, we outline what is known about (a) ice-shelf melt, volume loss, retreat, and calving, (b) ice-shelf-associated ecosystems through sub-ice, sediment-core, and pre-collapse and post-collapse studies, and (c) ecological responses in pelagic, sympagic, and benthic ecosystems. We then discuss major knowledge gaps and how science might address these gaps. This article is categorized under: Climate, Ecology, and Conservation 〉 Modeling Species and Community Interactions.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , NonPeerReviewed
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2023-06-12
    Description: While understanding feeding preferences of herbivores and carnivores is of major importance in ecology, we still know very little on the sensitivity of different functional groups to suboptimal stoichiometric resource quality. Here, we apply concepts of ecological stoichiometry to shed light on differences in the nutritional requirements of herbivores and carnivores, and to make predictions on the influence of suboptimal resource stoichiometric quality on the fitness of these different consumers to. Herbivores generally experience more variation in the quality of their resource than carnivores do, and these differences have likely shaped the extent to which coping mechanisms have evolved. Consequently, we expect 1) herbivores to maintain their stoichiometric homeostasis over a broader range of resource stoichiometry than carnivores, 2) the threshold elemental ratio (TER), i.e. the dietary carbon to nutrient ratio which maximizes fitness, of herbivores to be higher than that of carnivores, 3) a narrower and sharper knife-edge response in carnivores than herbivores and 4) asymmetric knife-edge responses indicating a higher sensitivity to the diet quality that consumers are not used to dealing with, namely nutrient limitation in carnivores and nutrient excess in herbivores. Our study poses that documenting the ranges of resource quality where consumer fitness declines in diverse organisms is a very promising avenue to increase our understanding of community composition and food web functioning.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2023-10-24
    Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉Firn describes the interstage product between snow and ice in cold regions of the earth, where annual snow fall exceeds the amount of snow melting. The continuing accumulation of snow leads to its densificiation due to overburden stress until it becomes ice. In the field of glaciology various attempts on simulating firn densification have been made and new models are still developed, as the knowledge of the firn column's density structure allows important derivations.〈/jats:p〉〈jats:p〉The presented study reassesses a model description for low density firn based on the process of grain boundary sliding presented by Alley in 1987 [1] using an optimisation approach. By comparing simulation results to 159 measured firn density profiles from Greenland and Antarctica it finds a possible additional dependency of the constitutive relation on the mean surface mass balance. This result is interpreted as an insufficient description of the stress regime.〈/jats:p〉
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    facet.materialart.
    Unknown
    Wiley
    In:  EPIC3PAMM, Wiley, 22(1), ISSN: 1617-7061
    Publication Date: 2023-10-24
    Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉Ice shelves are large floating ice masses, that are formed when glaciers are becoming afloat at the margin of ice sheets. One dominating mass loss mechanism of ice shelves is calving, describing the detachment of icebergs at the front. Ice shelves stabilize inland ice glaciers due to buttressing. If the stabilizing effect of an ice shelf vanishes because of disintegration or thinning, the corresponding glacier accelerates resulting in sea level rise.〈/jats:p〉〈jats:p〉To describe calving and disintegration of ice shelves, it is important to investigate fracture propagation in ice. A powerful method in fracture mechanics is the phase field method which is based on Griffith's theory. It approximates cracks in a diffuse manner by using a continuous scalar field. We propose a phase field fracture model for ice considering its characteristic material properties. The material behavior of ice depends on the considered time scales. On short time scales it behaves like a solid and while it acts like a fluid on long time scales, which classifies it as a viscoelastic material of Maxwell type. This has been verified by observations. The phase field method allows us to simulate typical fracture situations of ice shelves in Antarctica and Greenland.〈/jats:p〉
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2023-10-24
    Description: 〈jats:title〉Abstract〈/jats:title〉〈jats:p〉In cold regions of the earth, like Antarctica, Greenland or mountains at high altitude, the annual amount of deposited snow exceeds the amount of snow melting. Snow, which is more than one year old, is called firn. Over time firn transforms into ice by a sintering process, mainly driven by overburden pressure and temperature. This ultimately leads to the formation of glaciers and ice sheets.〈/jats:p〉〈jats:p〉We simulate firn densification based on the processes of sintering. The constitutive law represents grain boundary sliding, dislocation creep and diffusion. These mechanisms sum up to the overall densification which leads to the transformation of snow to ice. The model aims at obtaining a physics driven simulation tool for firn densification which provides data for a wider range of areas. It will contribute to develop better models and better understanding of the cryosphere.〈/jats:p〉
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2023-10-26
    Description: Study of the climate in the Mediterranean basin during different historical periods has taken on a particular importance, particularly regarding its role (together with other factors) in the evolution of human settlement patterns. Although the Roman age is traditionally considered a period with a favourable climate, recent studies have revealed considerable complexity in terms of regional climate variations. In this paper, we compare the hydrological change from speleothem proxy records with flood reconstructions from archaeological sites for Northern Tuscany (central Italy). We identify a period of oscillating climatic conditions culminating in a multidecadal dry event during the 1st century BC, followed by a century of increased precipitation at the beginning of the Roman Empire and subsequently a return to drier conditions in the 2nd century AD. The period of rainfall increase documented by the speleothems agrees with both the archaeological flood record as well as historical flood data available for the Tiber River, ca. 300 km to the south. These data also suggest a return to wetter conditions following the 3nd and 4rd centuries AD.
    Description: Published
    Description: 791-802
    Description: 5A. Ricerche polari e paleoclima
    Description: JCR Journal
    Keywords: climate changes ; geoarchaeology ; palaeoflooding ; Roman Age ; Hydrological changes during the Roman Climatic Optimum
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2023-10-26
    Description: Among major volatiles released from the Earth’s interior, CO2 is an important target for the international community. The interest is keenly motivated by the contribution of CO2 in the Earth’s carbon budget and its role on past, current, and future climate dynamics. In particular, the isotopic signature of CO2 is fundamental to characterize the source of this gas and its evolution up to the atmosphere. The recent development of new laser-based techniques has marked an important milestone for the scientific community by favoring both high-frequency and in situ stable isotope measurements. Among them, the Delta Ray IRIS (Thermo Scientific Inc., Waltham, USA) is one of the most promising instruments thanks to its high precision, its limited interferences with other gaseous species (such as H2S and/or SO2), and its internal calibration procedure. These characteristics and the relative easiness to transport the Delta Ray IRIS have encouraged its use on the field to analyze volcanic CO2 emissions in recent years but often with distinct customized protocols of measurements. In this study, various tests in the laboratory and on the field have been performed to study the dependence of CO2 isotope measurements on analytical, instrumental, and environmental conditions. We emphasize the exceptional ability of the Delta Ray IRIS to perform isotope measurements for a large range of CO2 concentration (200 ppm–100%) thanks to a dilution system and to get a reliable estimation of the real CO2 content from the diluted one. These tests lead to point out major recommendations on the use of Delta Ray IRIS and allow the development of adapted protocols to analyze CO2 emissions like in volcanic environments.
    Description: Published
    Description: 4598190
    Description: 4V. Processi pre-eruttivi
    Description: 5V. Processi eruttivi e post-eruttivi
    Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2023-10-26
    Description: This paper aims to define the stability over the time of chemical elemental patterns in some citrus varieties of PGI (Protected Geographical Indication) and not PGI Interdonato and Lunario cultivars coming from Italy and Turkey and to set up a range of markers useful to trace their geographical origin. During the 2015–2017 growing seasons, all fruits were collected and subjected to Inductively Coupled Mass spectrom etry (ICP-MS) analysis, in order to determine the multielemental chemical profiles. The chemical variabil ity was calculated for each element by Multi-way analysis of variance. The results highlighted how the measured Cr, Ni, Al, K, Fe and Zn levels mainly depend on the soil composition and the fingerprint allow to trace the geographical origins. Moreover, the stepwise linear discriminant analysis (SLDA) has allowed to correctly classify the 100% of lemon pulps provenances, based on Ni, Al, K, Ca and Na con tents. Finally, our study demonstrates the role played by harvest years, variety and soils composition whose interaction contributed to define the chemical fingerprints.
    Description: Published
    Description: 2628-2639
    Description: 6A. Geochimica per l'ambiente e geologia medica
    Description: JCR Journal
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2023-12-11
    Description: Phytoplankton are responsible for about 90% of the oceanic primary production, largely supporting marine food webs, and actively contributing to the biogeochemical cycling of carbon. Yet, increasing temperature and pCO2, along with higher dissolved nitrogen: phosphorus ratios in coastal waters are likely to impact phytoplankton physiology, especially in terms of photosynthetic rate, respiration, and dissolved organic carbon (DOC) production. Here, we conducted a full-factorial experiment to identify the individual and combined effects of temperature, pCO2, and N : P ratio on the antioxidant capacity and carbon metabolism of the diatom Phaeodactylum tricornutum. Our results demonstrate that, among these three drivers, temperature is the most influential factor on the physiology of this species, with warming causing oxidative stress and lower activity of antioxidant enzymes. Furthermore, the photosynthetic rate was higher under warmer conditions and higher pCO2, and, together with a lower dark respiration rate and higher DOC exudation, generated cells with lower carbon content. An enhanced oceanic CO2 uptake and an overall stimulated microbial loop benefiting from higher DOC exudation are potential longer-term consequences of rising temperatures, elevated pCO2 as well as shifted dissolved N : P ratios.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2023-12-11
    Description: Marine community diversity surveys require a reliable assessment to estimate ecosystem functions and their dynamics. For these, non-invasive environmental DNA (eDNA) metabarcoding is increasingly applied in zoological studies to complement or even replace traditional morphological identification methods. However, uncertainties remain about the accuracy of the diversity detected with eDNA to capture the actual diversity in the field. Here, we validate the reliability of eDNA metabarcoding in identifying metazoan biodiversity in highly dynamic marine waters of the North Sea. We analyzed biodiversity from water (eDNA) and zooplankton samples with cytochrome c oxidase subunit 1 (COI) and 18S rRNA (18S) metabarcoding at Helgoland Roads and validated the optimal molecular resolution by morphological and molecular zooplankton identification (metabarcoding) with the result of merely a few false-negative detections. eDNA and zooplankton metabarcoding resolved 354 species from all major and in total 16 metazoan phyla. This molecular genetic species inventory overlapped by 95.9% (COI) and 81.9% (18S) with published inventories of local, morphologically identified species, among them neozoa and rediscovered species. Even though half of all species were detected by both eDNA and zooplankton metabarcoding, the methods differed significantly in their detected diversity. eDNA metabarcoding performed very well in cnidarians and annelids, whereas zooplankton metabarcoding identified higher numbers of fish and malacostraca. Species assemblages significantly differed between the individual sampling events and the cumulative number of identified species increased steadily over the sampling period and did not reach saturation. About a third of the species were detected only once while a core community of 22 species was identified continuously. Our study confirms eDNA metabarcoding to be a powerful tool to identify and analyze North Sea fauna in highly dynamic waters and we recommend investing in high sampling efforts by repetitive sampling and replication using at least 0.45 μm filters to increase filtration volume.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...