Impacts of Greenland and Antarctic Ice Sheet melt on future Köppen climate zone changes simulated by an atmospheric and oceanic general circulation model

2020 ◽  
Vol 119 ◽  
pp. 102216
Author(s):  
Dimitri Defrance ◽  
Thibault Catry ◽  
Amélie Rajaud ◽  
Nadine Dessay ◽  
Benjamin Sultan
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Ice Sheet ◽  
Circulation Model ◽  
Antarctic Ice Sheet ◽  
Climate Zone ◽  
Oceanic General Circulation Model

First results from coupling the Parallel Ice Sheet Model with the Modular Ocean Model via an Antarctic ice-shelf cavity module

2021 ◽  
Author(s):  
Moritz Kreuzer ◽  
Ronja Reese ◽  
Willem Huiskamp ◽  
Stefan Petri ◽  
Torsten Albrecht ◽  
...  
Keyword(s):  
Time Scales ◽  
General Circulation ◽  
Ice Sheet ◽  
Circulation Model ◽  
Ocean Model ◽  
Global Ocean ◽  
Ice Shelf ◽  
Antarctic Ice Sheet ◽  
First Results ◽  
The Antarctic

<p>The past and future evolution of the Antarctic Ice Sheet is largely controlled by interactions between the ocean and floating ice shelves. To investigate these interactions, coupled ocean and ice sheet model configurations are required. Previous modelling studies have mostly relied on high resolution configurations, limiting these studies to individual glaciers or regions over short time scales of decades to a few centuries. To study global and long term interactions, we developed a framework to couple the dynamic ice sheet model PISM with the global ocean general circulation model MOM5 via the ice-shelf cavity module PICO. Since ice-shelf cavities are not resolved by MOM5, but parameterized with the box model PICO, the framework allows the ice sheet and ocean model to be run at resolution of 16 km and 3 degrees, respectively. We present first results from our coupled setup and discuss stability, feedbacks, and interactions of the Antarctic Ice Sheet and the global ocean system on millennial time scales.</p>

Modeling a 200-Yr Interruption of the Holocene Sapropel S1

2000 ◽  
Vol 53 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Paul G. Myers ◽  
Eelco J. Rohling
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Deep Convection ◽  
Circulation Model ◽  
Intermediate Water ◽  
Gulf Of Lions ◽  
The Holocene ◽  
Circulation Mode ◽  
Oceanic General Circulation Model ◽  
Water Formation

AbstractAn oceanic general circulation model, previously used to simulate the conditions associated with the Holocene Sapropel S1, is used to simulate the effects of a climate deterioration (represented as a cooling event) on the sapropelic circulation mode. The enhanced cooling (2°–3°C) induces deep convection in the Adriatic and the Gulf of Lions and intermediate water formation in the Aegean, where in all cases there had previously been only stagnant unventilated waters. The depths of ventilation (to ∼1250 m) are in agreement with core data from this period. The short decadal timescales involved in modifying the sapropelic circulation suggest that such a climatic deterioration may be associated with the interruption of S1 between 7100 and 6900 14C yr B.P., which divided the sapropel into two subunits.

scholarly journals Competing influences of the ocean, atmosphere and solid earth on transient Miocene Antarctic ice sheet variability

2021 ◽  
Author(s):  
Lennert Bastiaan Stap ◽  
Constantijn J. Berends ◽  
Meike D. W. Scherrenberg ◽  
Roderik S. W. van de Wal ◽  
Edward G. W. Gasson
Keyword(s):  
General Circulation ◽  
Ice Sheet ◽  
Circulation Model ◽  
Climate Forcing ◽  
Ice Shelf ◽  
Antarctic Ice Sheet ◽  
Ice Volume ◽  
Bedrock Topography ◽  
Co2 Levels ◽  
Transient Simulations

Abstract. Benthic δ18O levels vary strongly during the warmer-than-modern early- and mid-Miocene (23 to 14 Myr ago), suggesting a dynamic Antarctic ice sheet (AIS). So far, however, realistic simulations of the Miocene AIS have been limited to equilibrium states under different CO2 levels and orbital settings. Earlier transient simulations lacked ice-sheet-atmosphere interactions, and used a present-day rather than Miocene Antarctic bedrock topography. Here, we quantify the effect of ice-sheet-atmosphere interactions, running IMAU-ICE using climate forcing from Miocene simulations by the general circulation model GENESIS. Utilising a recently developed matrix interpolation method enables us to interpolate the climate forcing based on CO2 levels (between 280 and 840 ppm) as well as ice sheet configurations (between no ice and a large ice sheet). We furthermore implement recent reconstructions of Miocene Antarctic bedrock topography. We find that the positive albedo-temperature feedback, partly compensated by the negative ice-volume-precipitation feedback, increases hysteresis in the relation between CO2 and ice volume (V). Together, these ice-sheet-atmosphere interactions decrease the amplitude of AIS variability caused by 40-kyr forcing CO2 cycles by 21 % in transient simulations. Thereby, they also diminish the contribution of AIS variability to benthic δ18O fluctuations. Furthermore, we show that under equal atmospheric and oceanic forcing, the amplitude of 40-kyr transient AIS variability becomes 10 % smaller during the early- and mid-Miocene, due to the evolving bedrock topography. Lastly, we quantify the influence of ice shelf formation around the Antarctic margins, by comparing simulations with Last Glacial Maximum (LGM) basal melt conditions, to ones in which ice shelf growth is prevented. Ice shelf formation increases hysteresis in the CO2-V relation, and amplifies 40-kyr AIS variability by 19 % using LGM basal melt rates, and by 5 % in our reference setting.

Inferring the Last Interglacial West Antarctic Ice Sheet from the coupling of an ice core water stable isotope record and an atmospheric general circulation model

2020 ◽  
Author(s):  
Sentia Goursaud ◽  
Louise Sime ◽  
Eric Wolff
Keyword(s):  
General Circulation ◽  
Ice Core ◽  
Ice Sheet ◽  
Circulation Model ◽  
Last Interglacial ◽  
Antarctic Ice Sheet ◽  
West Antarctic Ice Sheet ◽  
West Antarctic ◽  
Isotope Record ◽  
Water Stable Isotope

<p><span><span>The Last Interglacial period (</span></span><span><span>130-115 ka BP, </span></span><span><span>hereafter LIG</span></span><span><span>) </span></span><span><span>is often considered as a</span></span> <span><span>prime example to study the effect of </span></span><span><span>warmer-than-present </span></span><span><span>temperatures on polar ice sheets evolution. As the debate mainly focuses on the causes and tip</span></span><span><span>ping</span></span><span><span> point of a potential collapse of the West Antarctic Ice Sheet </span></span><span><span>(hereafter </span></span><span><span>WAIS</span></span><span><span>), </span></span><span><span>few investigations examine the consequences of a wais collapse in terms of atmospheric circulation. </span></span><span><span>However, a knowledge of </span></span><span><span>the state of the atmosphere is necessary to use proxy data recorded in ice cores. </span></span><span><span>By analysing a new ice core drilled in Skytrain ice rise and using climate modeling, t</span></span><span><span>he WACSWAIN (WArm Climate Stability of West Antarctic ice sheet in the last Interglacial) </span></span><span><span>aims to </span></span><span><span>reconstruct WAIS extent during the LIG. Here, we use simulations from the atmospheric general circulation model HadCM3 </span></span> <span><span>with </span></span><span><span>different </span></span><span><span>WAIS configurations. We show that changes in temperature are directly linked to changes in orography through thermodynamic effects, as well as a linear sea ice extent rise over the Pacific Ocean with the WAIS reduction explained by a reversal of meridional winds turning southwards as the WAIS disappears.</span></span> <span><span>At the Skytrain ice rise, we show that not only the isotopic thermometer can be applied, but we also suggest that the water stable isotope record imprinted in the ice core will allow us to quantify the wais reduction.</span></span></p>

scholarly journals Ice-Age Climate and Continental Ice Sheets: Some Experiments with A General Circulation Model

1984 ◽  
Vol 5 ◽  
pp. 100-105 ◽  
Author(s):  
S. Manabe ◽  
A. J. Broccoli
Keyword(s):  
North America ◽  
General Circulation Model ◽  
Northern Hemisphere ◽  
General Circulation ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Circulation Model ◽  
Geological Evidence ◽  
The Difference ◽  
Continental Ice Sheets

The climatic influence of the land ice which existed 18 ka BP is investigated using a climate model developed at the Geophysical Fluid Dynamics Laboratory of the National Oceanic and Atmospheric Administration. The model consists of an atmospheric general circulation model coupled with a static mixed layer ocean model. Simulated climates are obtained from each of two versions of the model: one with the land-ice distribution of the present and the other with that of 18 ka BP.In the northern hemisphere, the difference in the distribution of sea surface temperature (SST) between the two experiments resembles the difference between the SST at 18 ka BP and at present as estimated by CLIMAP Project Members (1981). In the northern hemisphere a substantial lowering of air temperature also occurs in winter, with a less pronounced cooling during summer. The mid-tropospheric flow field is influenced by the Laurentide ice sheet and features a split jet stream straddling the ice sheet and a long wave trough along the east coast of North America. In the southern hemisphere of 18 ka BP, the ice sheet has little influence on temperature. An examination of hemispheric heat balances indicates that this is because only a small change in interhemispheric heat transport exists, as the In situ radiative compensation in the northern hemisphere counterbalances the effective reflection of solar radiation by continental ice sheets.Hydrologic changes in the model climate are also found, with statistically significant decreases in soil moisture occurring in a zone located to the south of the ice sheets in North America and Eurasia. These findings are consistent with some geological evidence of regionally drier climates from the last glacial maximum.

scholarly journals Coupling Planet Simulator Mars, a general circulation model of the Martian atmosphere, to the ice sheet model SICOPOLIS

2007 ◽  
Vol 55 (14) ◽  
pp. 2087-2096 ◽  
Author(s):  
O.J. Stenzel ◽  
B. Grieger ◽  
H.U. Keller ◽  
R. Greve ◽  
K. Fraedrich ◽  
...  
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Ice Sheet ◽  
Circulation Model ◽  
Martian Atmosphere
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