scholarly journals Correction to “ Water isotope module of the ECHAM atmospheric general circulation model: A study on timescales from days to several years” by G. Hoffmann et al.

1998 ◽  
Vol 103 (D18) ◽  
pp. 23323-23323 ◽  
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Atmospheric General Circulation Model ◽  
Circulation Model ◽  
Atmospheric General Circulation ◽  
Water Isotope

scholarly journals Influence of Last Glacial Maximum boundary conditions on the global water isotope distribution in an atmospheric general circulation model

2013 ◽  
Vol 9 (2) ◽  
pp. 789-809 ◽  
Author(s):  
T. Tharammal ◽  
A. Paul ◽  
U. Merkel ◽  
D. Noone
Keyword(s):  
Boundary Conditions ◽  
Surface Temperature ◽  
General Circulation Model ◽  
Last Glacial Maximum ◽  
General Circulation ◽  
Atmospheric General Circulation Model ◽  
Ice Sheet ◽  
Circulation Model ◽  
Atmospheric General Circulation ◽  
Water Isotope

Abstract. To understand the validity of δ18O proxy records as indicators of past temperature change, a series of experiments was conducted using an atmospheric general circulation model fitted with water isotope tracers (Community Atmosphere Model version 3.0, IsoCAM). A pre-industrial simulation was performed as the control experiment, as well as a simulation with all the boundary conditions set to Last Glacial Maximum (LGM) values. Results from the pre-industrial and LGM simulations were compared to experiments in which the influence of individual boundary conditions (greenhouse gases, ice sheet albedo and topography, sea surface temperature (SST), and orbital parameters) were changed each at a time to assess their individual impact. The experiments were designed in order to analyze the spatial variations of the oxygen isotopic composition of precipitation (δ18Oprecip) in response to individual climate factors. The change in topography (due to the change in land ice cover) played a significant role in reducing the surface temperature and δ18Oprecip over North America. Exposed shelf areas and the ice sheet albedo reduced the Northern Hemisphere surface temperature and δ18Oprecip further. A global mean cooling of 4.1 °C was simulated with combined LGM boundary conditions compared to the control simulation, which was in agreement with previous experiments using the fully coupled Community Climate System Model (CCSM3). Large reductions in δ18Oprecip over the LGM ice sheets were strongly linked to the temperature decrease over them. The SST and ice sheet topography changes were responsible for most of the changes in the climate and hence the δ18Oprecip distribution among the simulations.

scholarly journals Influence of LGM boundary conditions on the global water isotope distribution in an atmospheric general circulation model

2012 ◽  
Vol 8 (2) ◽  
pp. 1319-1368 ◽  
Author(s):  
T. Tharammal ◽  
A. Paul ◽  
U. Merkel ◽  
D. Noone
Keyword(s):  
Boundary Conditions ◽  
Surface Temperature ◽  
General Circulation Model ◽  
General Circulation ◽  
Atmospheric General Circulation Model ◽  
Ice Sheet ◽  
Circulation Model ◽  
Climate System Model ◽  
Atmospheric General Circulation ◽  
Water Isotope

Abstract. A series of experiments was conducted using a water isotope tracers-enabled atmospheric general circulation model (Community Atmosphere Model version 3.0, CAM3.0-Iso), by changing the individual boundary conditions (greenhouse gases, ice sheet albedo and topography, sea-surface temperature) each at a time to Last Glacial Maximum (LGM) values. In addition, a combined simulation with all the boundary conditions being set to LGM values was carried out. A pre-industrial (PI) simulation with boundary conditions taken according to the PMIP2 (Paleoclimate Modelling Intercomparison Project) protocol was performed as the control experiment. The experiments were designed in order to analyze the temporal and spatial variations of the oxygen isotopic composition of precipitation (δ18Oprecip) in response to individual climate factors. The change in topography (due to the change in land-ice cover) played a significant role in reducing the surface temperature and δ18Oprecip over North America. Exposed shelf areas and the ice sheet albedo reduced the Northern Hemisphere surface temperature and δ18Oprecip further. A global mean cooling of 4.1 °C was simulated with combined LGM boundary conditions compared to the control simulation, which was in agreement with previous experiments using the fully coupled Community Climate System Model (CCSM3). Large reductions in δ18Oprecip over the LGM ice sheets were highly correlated with the temperature decrease over them. The SST and ice sheet topography changes were found to be responsible for most of the changes in the climate and hence the δ18Oprecip distribution among the simulations.

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