GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Sensitivity of the thermohaline circulation in coupled oceanic GCM – atmospheric EBM experiments (1996)
    Springer
    Climate dynamics 12 (1996), S. 403-416 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract. We analyze the sensitivity of the oceanic thermohaline circulation (THC) regarding perturbations in fresh water flux for a range of coupled oceanic general circulation – atmospheric energy balance models. The energy balance model (EBM) predicts surface air temperature and fresh water flux and contains the feedbacks due to meridional transports of sensible and latent heat. In the coupled system we examine a negative perturbation in run-off into the southern ocean and analyze the role of changed atmospheric heat transports and fresh water flux. With mixed boundary conditions (fixed air temperature and fixed surface fresh water fluxes) the response is characterized by a completely different oceanic heat transport than in the reference case. On the other hand, the surface heat flux remains roughly constant when the air temperature can adjust in a model where no anomalous atmospheric transports are allowed. This gives an artificially stable system with nearly unchanged oceanic heat transport. However, if meridional heat transports in the atmosphere are included, the sensitivity of the system lies between the two extreme cases. We find that changes in fresh water flux are unimportant for the THC in the coupled system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003820050117
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Sensitivity of the thermohaline circulation in coupled oceanic GCM — atmospheric EBM experiments (1996)
    Springer
    Climate dynamics 12 (1996), S. 403-416 
    Details
    ISSN: 1432-0894
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We analyze the sensitivity of the oceanic thermohaline circulation (THC) regarding perturbations in fresh water flux for a range of coupled oceanic general circulation — atmospheric energy balance models. The energy balance model (EBM) predicts surface air temperature and fresh water flux and contains the feedbacks due to meridional transports of sensible and latent heat. In the coupled system we examine a negative perturbation in run-off into the southern ocean and analyze the role of changed atmospheric heat transports and fresh water flux. With mixed boundary conditions (fixed air temperature and fixed surface fresh water fluxes) the response is characterized by a completely different oceanic heat transport than in the reference case. On the other hand, the surface heat flux remains roughly constant when the air temperature can adjust in a model where no anomalous atmospheric transports are allowed. This gives an artificially stable system with nearly unchanged oceanic heat transport. However, if meridional heat transports in the atmosphere are included, the sensitivity of the system lies between the two extreme cases. We find that changes in fresh water flux are unimportant for the THC in the coupled system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00211686
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    Biome changes and their inferred climatic drivers in northern and eastern continental Asia at selected times since 40 cal ka bp (2018)
    Springer
    In:  Vegetation History and Archaeobotany, 27 (2). pp. 365-379.
    Details
    Publication Date: 2018-12-17
    Description: Recent global warming is pronounced in high-latitude regions (e.g. northern Asia), and will cause the vegetation to change. Future vegetation trends (e.g. the “arctic greening”) will feed back into atmospheric circulation and the global climate system. Understanding the nature and causes of past vegetation changes is important for predicting the composition and distribution of future vegetation communities. Fossil pollen records from 468 sites in northern and eastern Asia were biomised at selected times between 40 cal ka bp and today. Biomes were also simulated using a climate-driven biome model and results from the two approaches compared in order to help understand the mechanisms behind the observed vegetation changes. The consistent biome results inferred by both approaches reveal that long-term and broad-scale vegetation patterns reflect global- to hemispheric-scale climate changes. Forest biomes increase around the beginning of the late deglaciation, become more widespread during the early and middle Holocene, and decrease in the late Holocene in fringe areas of the Asian Summer Monsoon. At the southern and southwestern margins of the taiga, forest increases in the early Holocene and shows notable species succession, which may have been caused by winter warming at ca. 7 cal ka bp. At the northeastern taiga margin (central Yakutia and northeastern Siberia), shrub expansion during the last deglaciation appears to prevent the permafrost from thawing and hinders the northward expansion of evergreen needle-leaved species until ca. 7 cal ka bp. The vegetation-climate disequilibrium during the early Holocene in the taiga-tundra transition zone suggests that projected climate warming will not cause a northward expansion of evergreen needle-leaved species.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1007/s00334-017-0653-8
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 4
    facet.materialart.
    Unknown
    Atmospheric bridge on orbital time scales (2017)
    Springer
    In:  Theoretical and Applied Climatology, 128 (3-4). pp. 709-718.
    Details
    Publication Date: 2018-12-17
    Description: Large-scale atmospheric patterns are examined on orbital timescales using a climate model which explicitly resolves the atmosphere–ocean–sea ice dynamics. It is shown that, in contrast to boreal summer where the climate mainly follows the local radiative forcing, the boreal winter climate is strongly determined by modulation of circulation modes linked to the Arctic Oscillation/North Atlantic Oscillation (AO/NAO) and the Northern/Southern Annular Modes. We find that during a positive phase of the AO/NAO the convection in the tropical Pacific is below normal. The related atmospheric circulation provides an atmospheric bridge for the precessional forcing inducing a non-uniform temperature anomalies with large amplitudes over the continents. We argue that this is important for mechanisms responsible for multi-millennial climate variability and glacial inception.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.1007/s00704-015-1725-2
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 5
    facet.materialart.
    Unknown
    Holocene Environmental Variability in the Arctic Gateway (2015)
    Springer
    In:  In: Integrated Analysis of Interglacial Climate Dynamics (INTERDYNAMIC). , ed. by Schulz, M. and Paul, A. Springer Briefs in Earth System Sciences . Springer, Berlin, pp. 37-42. ISBN 978-3-319-00692-5
    Details
    Publication Date: 2019-09-23
    Description: Environmental changes in the region connecting the Arctic Ocean and the northern North Atlantic were studied for the last 9,000 years (9 ka) by a combination of proxy-based paleoceanographic reconstructions as well as transient and time-slice simulations with climate models. Today, the area is perennially ice-covered in the west and ice-free in the east. Results show that sea-ice conditions were highly variable on short timescales in the last 9 ka. However, sea-ice proxies reveal an overall eastward movement of the sea-ice margin, in line with a decreasing influence of warm Atlantic Water advected to the Arctic Ocean. These cooling trends were rapidly reversed 100 years ago and replaced by the general warming in the Arctic. Model results show a consistently high freshwater input to the Arctic Ocean during the last 7 ka. The signal is robust against the Holocene cooling trend, however sensitive towards the warming trend of the last century. These results may play a role in the observed Arctic changes.
    Type: Book chapter , NonPeerReviewed
    DOI: 10.1007/978-3-319-00693-2_7
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Book chapter
  • 6
    facet.materialart.
    Unknown
    Challenges in the Paleoclimatic Evolution of the Arctic and Subarctic Pacific since the Last Glacial Period—The Sino–German Pacific–Arctic Experiment (SiGePAX) (2019)
    MDPI
    In:  Challenges, 10 (1). Art.Nr. 13.
    Details
    Publication Date: 2021-01-08
    Description: Arctic and subarctic regions are sensitive to climate change and, reversely, provide dramatic feedbacks to the global climate. With a focus on discovering paleoclimate and paleoceanographic evolution in the Arctic and Northwest Pacific Oceans during the last 20,000 years, we proposed this German–Sino cooperation program according to the announcement “Federal Ministry of Education and Research (BMBF) of the Federal Republic of Germany for a German–Sino cooperation program in the marine and polar research”. Our proposed program integrates the advantages of the Arctic and Subarctic marine sediment studies in AWI (Alfred Wegener Institute) and FIO (First Institute of Oceanography). For the first time, the collection of sediment cores can cover all climatological key regions in the Arctic and Northwest Pacific Oceans. Furthermore, the climate modeling work at AWI enables a “Data-Model Syntheses”, which are crucial for exploring the underlying mechanisms of observed changes in proxy records.
    Type: Article , PeerReviewed
    Format: text
    DOI: 10.3390/challe10010013
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 7
    facet.materialart.
    Unknown
    Challenges in the Paleoclimatic Evolution of the Arctic and Subarctic Pacific since the Last Glacial Period — the Sino-German Pacific – Arctic Experiment (SiGePAX) (2019)
    MDPI
    In:  EPIC3Challenges, MDPI, 10(1), pp. 1-22, ISSN: 2078-1547
    Details
    Publication Date: 2021-02-16
    Description: Arctic and subarctic regions are sensitive to climate change and, reversely, provide dramatic feedbacks to the global climate. With a focus on discovering paleoclimate and paleoceanographic evolution in the Arctic and Northwest Pacific Oceans during the last 20,000 years, we proposed this German–Sino cooperation program according to the announcement “Federal Ministry of Education and Research (BMBF) of the Federal Republic of Germany for a German–Sino cooperation program in the marine and polar research”. Our proposed program integrates the advantages of the Arctic and Subarctic marine sediment studies in AWI (Alfred Wegener Institute) and FIO (First Institute of Oceanography). For the first time, the collection of sediment cores can cover all climatological key regions in the Arctic and Northwest Pacific Oceans. Furthermore, the climate modeling work at AWI enables a “Data-Model Syntheses”, which are crucial for exploring the underlying mechanisms of observed changes in proxy records.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 8
    facet.materialart.
    Unknown
    Concept of a Sino-German Summer School on Multiscale Processes in Oceans and the Atmosphere (2020)
    MDPI
    In:  EPIC3Challenges, MDPI, 11(2)(24), ISSN: 2078-1547
    Details
    Publication Date: 2021-07-01
    Description: A concept for an interdisciplinary summer school for “multiscale processes in oceans and the atmosphere” is presented. It aims to deepen students’ understanding of scientific issues as well as their experience in multicultural communication. The theme covers climate evolution, which is partially dominated by far-reaching anthropogenic changes and their possible consequences on the Earth’s system. An integrated approach helps to change rigid subject-specific mindsets among faculties and students and across cultures, so as to broaden their horizons in both research and life. Research has shown, however, that the development of intercultural competence in students does not happen automatically but needs to be fostered and supported. Therefore, a primary goal is also to provide young researchers from several countries (mainly China and Germany) with the opportunity to gain more indepth knowledge on research in Germany, to be exposed to scientific culture, and thus to prepare for foreign research visits either during the PhD phase or as postdoctoral fellows, supporting the internationalization of education and opportunities in marine sciences. Finally, the students have the chance to further develop their scientific profiles by attending scientific talks, lab exercises, and excursions and by combining rigorous scientific disciplines with the awareness of multidisciplinary issues related to the topic of global climate change
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , peerRev
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 9
    facet.materialart.
    Unknown
    A Synoptic Scale Perspective on Greenland Ice Core d18O Variability and Related Teleconnection Patterns (2021)
    MDPI
    In:  EPIC3Atmosphere, MDPI, 12(3), ISSN: 2073-4433
    Details
    Publication Date: 2021-07-01
    Description: The variability of stable oxygen isotope ratios (δ18O) from Greenland ice cores is commonly linked to changes in local climate and associated teleconnection patterns. In this respect, in this study we investigate ice core δ18O variability from a synoptic scale perspective to assess the potential of such records as proxies for extreme climate variability and associated weather patterns. We show that positive (negative) δ18O anomalies in three southern and central Greenland ice cores are associated with relatively high (low) Rossby Wave Breaking (RWB) activity in the North Atlantic region. Both cyclonic and anticyclonic RWB patterns associated with high δ18O show filaments of strong moisture transport from the Atlantic Ocean towards Greenland. During such events, warm and wet conditions are recorded over southern, western and central part of Greenland. In the same time the cyclonic and anticyclonic RWB patterns show enhanced southward advection of cold polar air masses on their eastern side, leading to extreme cold conditions over Europe. The association between high δ18O winters in Greenland ice cores and extremely cold winters over Europe is partly explained by the modulation of the RWB frequency by the tropical Atlantic sea surface temperature forcing, as shown in recent modeling studies. We argue that δ18O from Greenland ice cores can be used as a proxy for RWB activity in the Atlantic European region and associated extreme weather and climate anomalies.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
  • 10
    facet.materialart.
    Unknown
    Opening of the Fram Strait led to the establishment of a modern-like three-layer stratification in the Arctic Ocean during the Miocene (2021)
    Springer
    In:  EPIC3arktos, Springer, ISSN: 2364-9461
    Details
    Publication Date: 2021-02-14
    Description: The tectonic opening of the Fram Strait (FS) was critical to the water exchange between the Atlantic Ocean and the Arctic Ocean, and caused the transition from a restricted to a ventilated Arctic Ocean during early Miocene. If and how the water exchange between the Arctic Ocean and the North Atlantic influenced the global current system is still disputed. We apply a fully coupled atmosphere–ocean–sea-ice model to investigate stratification and ocean circulation in the Arctic Ocean in response to the opening of the FS during early-to-middle Miocene. Progressive widening of the FS gateway in our simulation causes a moderate warming, while salinity conditions in the Nordic Seas remain similar. On the contrary, with increasing FS width, Arctic temperatures remain unchanged and salinity changes appear to steadily become stronger. For a sill depth of ~ 1500 m, we achieve ventilation of the Arctic Ocean due to enhanced import of saline Atlantic water through an FS width of ~ 105 km. Moreover, at this width and depth, we detect a modern-like three-layer stratification in the Arctic Ocean. The exchange flow through FS is characterized by vertical separation of a low-salinity cold outflow from the Arctic Ocean confined to a thin upper layer, an intermediate saline inflow from the Atlantic Ocean below, and a cold bottom Arctic outflow. Using a significantly shallower and narrower FS during the early Miocene, our study suggests that the ventilation mechanisms and stratification in the Arctic Ocean are comparable to the present-day characteristics.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Format: application/pdf
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER (OA)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...