scholarly journals A global climatology of the ocean surface during the Last Glacial Maximum mapped on a regular grid (GLOMAP)

2021 ◽  
Vol 17 (2) ◽  
pp. 805-824
Author(s):  
André Paul ◽  
Stefan Mulitza ◽  
Rüdiger Stein ◽  
Martin Werner
Keyword(s):  
Sea Ice ◽  
Last Glacial Maximum ◽  
Climate Sensitivity ◽  
Ocean Surface ◽  
Glacial Maximum ◽  
Sea Ice Extent ◽  
Equilibrium Climate Sensitivity ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. We present a climatology of the near-sea-surface temperature (NSST) anomaly and the sea-ice extent during the Last Glacial Maximum (LGM, 23 000–19 000 years before present) mapped on a global regular 1∘×1∘ grid. It is an extension of the Glacial Atlantic Ocean Mapping (GLAMAP) reconstruction of the Atlantic NSST based on the faunal and floral assemblage data of the Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface (MARGO) project and several recent estimates of the LGM sea-ice extent. Such a gridded climatology is highly useful for the visualization of the LGM climate, calculation of global and regional NSST averages, and estimation of the equilibrium climate sensitivity, as well as a boundary condition for atmospheric general circulation models. The gridding of the sparse NSST reconstruction was done in an optimal way using the Data-Interpolating Variational Analysis (DIVA) software, which takes into account the uncertainty in the reconstruction and includes the calculation of an error field. The resulting Glacial Ocean Map (GLOMAP) confirms the previous findings by the MARGO project regarding longitudinal and meridional NSST differences that were greater than today in all oceans. Taken at face value, the estimated global and tropical cooling would imply an equilibrium climate sensitivity at the lower end of the currently accepted range. However, because of anticipated changes in the seasonality and thermal structure of the upper ocean during the LGM as well as uneven spatial sampling, the estimated cooling and implied climate sensitivity are likely to be biased towards lower values.

scholarly journals A global climatology of the ocean surface during the Last Glacial Maximum mapped on a regular grid (GLOMAP)

2020 ◽  
Author(s):  
André Paul ◽  
Stefan Mulitza ◽  
Rüdiger Stein ◽  
Martin Werner
Keyword(s):  
Sea Ice ◽  
Last Glacial Maximum ◽  
Climate Sensitivity ◽  
Ocean Surface ◽  
Glacial Maximum ◽  
Sea Ice Extent ◽  
Equilibrium Climate Sensitivity ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. We present a climatology of the sea-surface temperature (SST) anomaly and the sea-ice extent during the Last Glacial Maximum (LGM, 23 000–19 000 years before present) mapped on a global regular 1° × 1° grid. It is an extension of the Glacial Atlantic Ocean Mapping (GLAMAP) reconstruction of the Atlantic SST based on the results of the Multiproxy Approach for the Reconstruction of the Glacial Ocean Surface (MARGO) project and several recent estimates of the LGM sea-ice extent. Such a gridded climatology is highly useful for the visualization of the LGM climate, calculation of global and regional SST averages and estimation of the equilibrium climate sensitivity, as well as a boundary condition for atmospheric general circulation models. The gridding of the sparse SST reconstruction was done in an optimal way using the Data-Interpolating Variational Analysis (DIVA) software, which takes into account the uncertainty on the reconstruction and includes the calculation of an error field. The resulting Glacial Ocean Map (GLOMAP) confirmed the previous findings by the MARGO project regarding longitudinal and meridional SST differences that were greater than today in all oceans and an equilibrium climate sensitivity at the lower end of the currently accepted range.

Too much of a good thing: sea ice extent may have forced emperor penguins into refugia during the last glacial maximum

2015 ◽  
Vol 21 (6) ◽  
pp. 2215-2226 ◽  
Author(s):  
Jane L. Younger ◽  
Gemma V. Clucas ◽  
Gerald Kooyman ◽  
Barbara Wienecke ◽  
Alex D. Rogers ◽  
...  
Keyword(s):  
Sea Ice ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Good Thing ◽  
Sea Ice Extent ◽  
Last Glacial ◽  
Emperor Penguins ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Reconstruction of sea-surface temperature, salinity, and sea-ice cover in the northern North Atlantic during the last glacial maximum based on dinocyst assemblages

2000 ◽  
Vol 37 (5) ◽  
pp. 725-750 ◽  
Author(s):  
Anne de Vernal ◽  
Claude Hillaire-Marcel ◽  
Jean-Louis Turon ◽  
Jens Matthiessen
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Last Glacial Maximum ◽  
North Atlantic ◽  
Ice Cover ◽  
Glacial Maximum ◽  
Sea Surface ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Past sea-surface conditions over the northern North Atlantic during the last glacial maximum were examined from the study of 61 deep-sea cores. The last glacial maximum time slice studied here corresponds to an interval between Heinrich layers H2 and H1, and spanning about 20-16 ka on a 14C time scale. Transfer functions based on dinocyst assemblages were used to reconstruct sea-surface temperature, salinity, and sea-ice cover. The results illustrate extensive sea-ice cover along the eastern Canadian margins and sea-ice spreading, only during winter, over most of the northern North Atlantic. On the whole, much colder winter prevailed, despite relatively mild conditions in August (10-15°C at most offshore sites), thus suggesting a larger seasonal contrast of temperatures than today. Lower salinity than at present is reconstructed, especially along the eastern Canadian and Scandinavian margins, likely because of meltwater supply from the surrounding ice sheets. These reconstructions contrast with those established by CLIMAP on the basis of planktonic foraminifera. These differences are discussed with reference to the stratigraphical frame of the last glacial maximum, which was not the coldest phase of the last glacial stage. The respective significance of dinocyst and foraminifer records is also examined in terms of the thermohaline characteristics of surface waters and the vertical structure of upper water masses, which was apparently much more stratified than at present in the northern North Atlantic, thus preventing deep-water formation.

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