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
  • 1
    Publication Date: 2024-03-21
    Description: Precipitation extremes with devastating socioeconomic consequences within the South American Monsoon System (SAMS) are expected to become more frequent in the near future. The complexity in SAMS behavior, however, poses severe challenges for reliable future projections. Thus, robust paleomonsoon records are needed to constrain the high spatiotemporal variability in the response of SAMS rainfall to different climatic drivers. This study uses Ti/Ca ratios from X‐ray fluorescence scanning of a sediment core retrieved off eastern Brazilian to trace precipitation changes over the past 322 Kyr. The results indicate that despite the spatiotemporal complexity of the SAMS, insolation forcing is the primary pacemaker of variations in the monsoonal system. Additional modulation by atmospheric p CO 2 suggests that SAMS intensity over eastern Brazil will be suppressed by rising CO 2 emissions in the future. Lastly, our record reveals an unprecedented strong and persistent wet period during Marine Isotope Stage 6 driven by anomalously strong trade winds.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2024-03-21
    Description: Cold‐water coral (CWC) reefs and mounds are and have been biodiversity hotspots of the deep sea. As their occurrence depends on specific environmental parameters, gaining hindsight on changing ocean conditions under on‐going climate change is the key to a better understanding of CWC mound development through time. A convenient technique for reconstructing the palaeoenvironment during periods of CWC mound growth is by extracting geochemical proxies from biologically mediated carbonates. Here, the focus is on probably the two most abundant calcareous archives, that are, cold‐water Scleractinia and Foraminifera, with an overview of the geochemical proxies (selection) used in these aragonitic and calcitic skeletons from CWC mounds. A particular emphasis is set on constraining proxies for temperature, salinity, seawater density, seawater carbonate systems parameters (pH, CO 3 2− ), nutrients, oxygen and water mass tracers.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2024-03-21
    Description: The continental expression of global cooling during the Miocene Climate Transition in Central Asia is poorly documented, as the tectonically active setting complicates the correlation of Neogene regional and global climatic developments. This study presents new geochemical data (CaSO 4 content, carbonate δ 13 C and δ 18 O) from the endorheic alluvial‐lacustrine Aktau succession (Ili Basin, south‐east Kazakhstan) combined with findings from the previously published facies evolution. Time series analysis revealed long‐eccentricity forcing of the paleohydrology throughout the entire succession, split into several facies‐dependent segments. Orbital tuning, constrained by new laser ablation U‐Pb dates and a preexisting magnetostratigraphy, places the succession in a 5.0 Ma long interval in the middle to late Miocene (15.6 to 10.6 Ma). The long‐term water accumulation in the Ili Basin followed the timing of the Miocene Climate Transition, suggesting increased precipitation in the catchment area in response to climate cooling and stronger westerly winds. This was paced by minima of the 2.4 Ma eccentricity cycle, which favored the establishment of a discharge playa (~14.3 Ma) and a perennial lake (12.6 to 11.8 Ma). Furthermore, low obliquity amplitudes (nodes) caused a transient weakening of the westerlies at ~13.7 to 13.5 Ma and at ~12.7 Ma, resulting in negative hydrological budgets and salinization. Flooding of the windward Ili Basin coeval with aridification in the leeward basins suggests that the Tian Shan was a climate boundary already in the middle Miocene. Our results emphasize the impact of climate fluctuations on the westerlies' strength and thus on Central Asian hydrology.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2024-02-07
    Description: During the last ice age, the Northern Hemisphere experienced a series of abrupt millennial-scale climatic changes linked to variations in the strength of the Atlantic Meridional Overturning Circulation and sea-ice extent. However, our understanding of their impacts on decadal-scale climate variability in central Europe has been limited by the lack of high-resolution continental archives. Here, we present a near annual-resolution climate proxy record of central European temperature reconstructed from the Eifel maar lakes of Holzmaar and Auel in Germany, spanning the past 60,000 years. The lake sediments reveal a series of previously undocumented multidecadal climate cycles of around 20 to 150 years that persisted through the last glacial cycle. The periodicity of these cycles suggests that they are related to the Atlantic multidecadal climate oscillations found in the instrumental record and in other climate archives during the Holocene. Our record shows that multidecadal variability in central Europe was strong during all warm interstadials, but was substantially muted during all cold stadial periods. We suggest that this decrease in multidecadal variability was the result of the atmospheric circulation changes associated with the weakening of the Atlantic Meridional Overturning Circulation and the expansion of North Atlantic sea-ice cover during the coldest parts of the last ice age.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Format: other
    Format: text
    Format: other
    Format: other
    Format: other
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2023-12-13
    Description: Members of the archaeal phylum Bathyarchaeota are widespread and abundant in the energy-deficient marine subsurface sediments. However, their life strategies have remained largely elusive. Here, we provide genetic evidence that some lineages of Bathyarchaeota are acetogens, being capable of homoacetogenesis, a metabolism so far restricted to the domain Bacteria. Metabolic reconstruction based on genomic bins assembled from the metagenome of deep-sea subsurface sediments shows that the metabolism of some lineages of Bathyarchaeota is similar to that of bona fide bacterial homoacetogens, by having pathways for acetogenesis and for the fermentative utilization of a variety of organic substrates. Heterologous expression and activity assay of the acetate kinase gene ack from Bathyarchaeota, demonstrate further the capability of these Bathyarchaeota to grow as acetogens. The presence and expression of bathyarchaeotal genes indicative of active acetogenesis was also confirmed in Peru Margin subsurface sediments where Bathyarchaeota are abundant. The analyses reveal that this ubiquitous and abundant subsurface archaeal group has adopted a versatile life strategy to make a living under energy-limiting conditions. These findings further expand the metabolic potential of Archaea and argue for a revision of the role of Archaea in the carbon cycle of marine sediments.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2023-07-11
    Description: Phytoplankton photosynthesis is a critical flux in the carbon cycle, accounting for approximately 40% of the carbon dioxide fixed globally on an annual basis and fuelling the productivity of aquatic food webs. However, rapid evolutionary responses of phytoplankton to warming remain largely unexplored, particularly outside the laboratory, where multiple selection pressures can modify adaptation to environmental change. Here, we use a decade-long experiment in outdoor mesocosms to investigate mechanisms of adaptation to warming (+4 °C above ambient temperature) in the green alga Chlamydomonas reinhardtii, in naturally assembled communities. Isolates from warmed mesocosms had higher optimal growth temperatures than their counterparts from ambient treatments. Consequently, warm-adapted isolates were stronger competitors at elevated temperature and experienced a decline in competitive fitness in ambient conditions, indicating adaptation to local thermal regimes. Higher competitive fitness in the warmed isolates was linked to greater photosynthetic capacity and reduced susceptibility to photoinhibition. These findings suggest that adaptive responses to warming in phytoplankton could help to mitigate projected declines in aquatic net primary production by increasing rates of cellular net photosynthesis.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2023-02-10
    Description: Microbial communities often exhibit incredible taxonomic diversity, raising questions regarding the mechanisms enabling species coexistence and the role of this diversity in community functioning. On the one hand, many coexisting but taxonomically distinct microorganisms can encode the same energy-yielding metabolic functions, and this functional redundancy contrasts with the expectation that species should occupy distinct metabolic niches. On the other hand, the identity of taxa encoding each function can vary substantially across space or time with little effect on the function, and this taxonomic variability is frequently thought to result from ecological drift between equivalent organisms. Here, we synthesize the powerful paradigm emerging from these two patterns, connecting the roles of function, functional redundancy and taxonomy in microbial systems. We conclude that both patterns are unlikely to be the result of ecological drift, but are inevitable emergent properties of open microbial systems resulting mainly from biotic interactions and environmental and spatial processes.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2022-10-06
    Description: A threat of irreversible damage should prompt action to mitigate climate change, according to the United Nations Framework Convention on Climate Change, which serves as a basis for international climate policy. CO2-induced climate change is known to be largely irreversible on timescales of many centuries1, as simulated global mean temperature remains approximately constant for such periods following a complete cessation of carbon dioxide emissions while thermosteric sea level continues to rise1,2,3,4,5,6. Here we use simulations with the Canadian Earth System Model to show that ongoing regional changes in temperature and precipitation are significant, following a complete cessation of carbon dioxide emissions in 2100, despite almost constant global mean temperatures. Moreover, our projections show warming at intermediate depths in the Southern Ocean that is many times larger by the year 3000 than that realized in 2100. We suggest that a warming of the intermediate-depth ocean around Antarctica at the scale simulated for the year 3000 could lead to the collapse of the West Antarctic Ice Sheet, which would be associated with a rise in sea level of several metres2,7,8.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    facet.materialart.
    Unknown
    Wiley-Blackwell
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/other
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    facet.materialart.
    Unknown
    Wiley-Blackwell
    In:  Crop Adaptation to Climate Change
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/bookPart
    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...