Oceanic forcing of Antarctic climate change: A study using a stretched-grid atmospheric general circulation model

• Published in: Journal of Climate
• Main Authors: Krinner, Gerhard, Largeron, Chloé, Ménégoz, Martin, Agosta, Cécile, Brutel-Vuilmet, Claire
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Meteorological Society 2014
• Subjects: Antarctica; climate change; oceanic forcing; Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Antarc*; Antarctic
• Online Access: https://orbi.uliege.be/handle/2268/143954; https://doi.org/10.1175/JCLI-D-13-00367.1

peer reviewed A variable-resolution atmospheric general circulation model (AGCM) is used for climate change projections over the Antarctic. The present-day simulation uses prescribed observed sea-surface conditions, while a set of five simulations for the end of the 21st century (2070-2099) under the SRES-A1B scenario uses sea- surface condition anomalies from selected CMIP3 coupled ocean-atmosphere climate models. Analysis of the results shows that the prescribed sea-surface condition anomalies have a very strong influence on the simulated climate change on the Antarctic continent, largely dominating the direct effect of the prescribed greenhouse gas concentration changes in the AGCM simulations. Complementary simulations with idealized forcings confirm these results. An analysis of circulation changes using self-organizing maps shows that the simulated climate change on regional scales is not principally caused by shifts of the frequencies of the dominant circulation patterns, except for precipitation changes in some coastal regions. The study illustrates that in some respects the use of bias-corrected sea- surface boundary conditions in climate projections with a variable-resolution atmospheric general circulation model has some distinct advantages over the use of limited-area atmospheric circulation models directly forced by generally biased coupled climate model output.