GLORIA

GEOMAR Library Ocean Research Information Access

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • SAGE Publications  (4)
Material
Publisher
  • SAGE Publications  (4)
Language
Subjects(RVK)
  • 1
    Online Resource
    Online Resource
    SAGE Publications ; 2020
    In:  The Holocene Vol. 30, No. 7 ( 2020-07), p. 996-1015
    In: The Holocene, SAGE Publications, Vol. 30, No. 7 ( 2020-07), p. 996-1015
    Abstract: The earliest part of the Holocene, from 11.5k to 7k (k = 1000 years before present), is a critical transition period between the relatively cold last deglaciation and the warm middle Holocene. It is marked by more pronounced seasonality and reduced greenhouse gases (GHGs) than the present state, as well as by the presence of the Laurentide Ice Sheet (LIS) and glacial meltwater perturbation. This paper performs experiments under pre-industrial and different early-Holocene regimes with AWI-ESM (Alfred Wegener Institute–Earth System Model), a state-of-the-art climate model with unstructured mesh and varying resolutions, to examine the sensitivity of the simulated Atlantic meridional overturning circulation (AMOC) to early-Holocene insolation, GHGs, topography (including properties of the ice sheet), and glacial meltwater perturbation. In the experiments with early-Holocene Earth orbital parameters and GHGs applied, the AWI-ESM simulation shows a JJA (June–July–August) warming and DJF (December–January–February) cooling over the mid and high latitudes compared with pre-industrial conditions, with amplification over the continents. The presence of the LIS leads to an additional regional cooling over the North America. We also simulate the meltwater event around 8.2k. Big discrepancies are found in the oceanic responses to different locations and magnitudes of freshwater discharge. Our experiments, which compare the effects of freshwater release evenly across the Labrador Sea to a more precise injection along the western boundary of the North Atlantic (the coastal region of LIS), show significant differences in the ocean circulation response, as the former produces a major decline of the AMOC and the latter yields no obvious effect on the strength of the thermohaline circulation. Furthermore, proglacial drainage of Lakes Agassiz and Ojibway leads to a fast spin-down of the AMOC, followed, however, by a gradual recovery. Most hosing experiments lead to a warming over the Nordic Sea and Barents Sea of varying magnitudes, because of an enhanced inflow from lower latitudes and a northward displacement of the North Atlantic deep convection. These processes exist in both of our high- and low-resolution experiments, but with some local discrepancies such as (1) the hosing-induced subpolar warming is much less pronounced in the high-resolution simulations; (2) LIS coastal melting in the high-resolution model leads to a slight decrease in the AMOC; and (3) the convection formation site in the low- and high-resolution experiments differs, in the former mainly over northeastern North Atlantic Ocean, but in the latter over a very shallow subpolar region along the northern edge of the North Atlantic Ocean. In conclusion, we find that our simulations capture spatially heterogeneous responses of the early-Holocene climate.
    Type of Medium: Online Resource
    ISSN: 0959-6836 , 1477-0911
    RVK:
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2020
    detail.hit.zdb_id: 2027956-5
    SSG: 14
    SSG: 3,4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    SAGE Publications ; 2003
    In:  The Holocene Vol. 13, No. 3 ( 2003-04), p. 335-342
    In: The Holocene, SAGE Publications, Vol. 13, No. 3 ( 2003-04), p. 335-342
    Abstract: Recent geological studies have revealed that the freshwater input to the Arctic Ocean was highly variable during the Holocene. In the present study, the influence of mid-Holocene river runoff on large-scale Arctic ocean/sea-ice dynamics is examined using a general circulation model. A palaeohydrological forcing for the time interval around 6 ka BP ( 14 C timescale) is constructed by compiling data from the available literature. Keeping all other forcing fields and bottom topography of the ocean model at present-day values, the effect of a changed freshwater input to the Arctic Ocean is isolated. The model shows that freshwater supply is vitally important for the polar oceanic circulation. In particular, a close connection between Siberian river runoff and the path of the Transpolar Drift (TPD) is found. Consistent with palaeoceanographic findings of driftwood delivery to the Canadian Arctic Archipelago and Baffin Bay, the model results suggest that enhanced freshwater discharge during the mid-Holocene caused an eastward shift of the TPD with strengthened outflow through Fram Strait.
    Type of Medium: Online Resource
    ISSN: 0959-6836 , 1477-0911
    RVK:
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2003
    detail.hit.zdb_id: 2027956-5
    SSG: 14
    SSG: 3,4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    In: The Holocene, SAGE Publications, Vol. 16, No. 3 ( 2006-04), p. 321-330
    Abstract: The Ras Umm Sidd coral 6180 record from the northern Red Sea is the northernmost centuries long coral time series that is currently available in seasonal resolution (AD 1750-1995). Here we investigate climate patterns associated with the coral 6180 time series separately for boreal winter and summer, using instrumental and reconstructed climate fields for the European-Middle East region. The winter coral 6180 record is associated with dominant modes of sea-level pressure, temperature and precipitation variability in the European-Middle East region, which reflect the Arctic Oscillation/North Atlantic Oscillation (AO/ NAO) phenomenon. The summer coral 6180 record is associated with an atmospheric pattern having its main centre of action over southwestern Scandinavia/northern Great Britain. The connection between these large-scale atmospheric circulation patterns and the coral time series was stable during the past 250 years. During winter, eastern Mediterranean/Middle East climate, as reflected in the coral 6180 record, is strongly controlled by the AO/NAO. In contrast, large-scale atmospheric circulation processes over the European-Middle East region are relatively less important for northern Red Sea climate during summer. The results suggest a high potential for seasonally resolved proxy records derived from fossil corals of the northern Red Sea to provide information on winter and summer climate patterns of the Middle East European region for time intervals of the Holocene epoch or the last interglacial period.
    Type of Medium: Online Resource
    ISSN: 0959-6836 , 1477-0911
    RVK:
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2006
    detail.hit.zdb_id: 2027956-5
    SSG: 14
    SSG: 3,4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Online Resource
    Online Resource
    SAGE Publications ; 2016
    In:  The Holocene Vol. 26, No. 7 ( 2016-07), p. 1169-1170
    In: The Holocene, SAGE Publications, Vol. 26, No. 7 ( 2016-07), p. 1169-1170
    Type of Medium: Online Resource
    ISSN: 0959-6836 , 1477-0911
    RVK:
    Language: English
    Publisher: SAGE Publications
    Publication Date: 2016
    detail.hit.zdb_id: 2027956-5
    SSG: 14
    SSG: 3,4
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...