Response of the Upper-Level Monsoon Anticyclones and Ozone to Abrupt CO₂ Changes ...

• Main Authors: Tweedy, Olga V., Oman, Luke D., Waugh, Darryn W., Schoeberl, Mark R., Douglass, Anne R., Li, Feng
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU 2021
• Subjects: Pacific; Sea ice
• Online Access: https://dx.doi.org/10.13016/m2v6v7-hf50; https://mdsoar.org/handle/11603/26695

The summer monsoon anticyclones are the dominant climatological features of the Northern Hemispheric (NH) summertime circulation in the upper troposphere and lower stratosphere (UTLS). However, the response of these anticyclones to the increased levels of E CO₂ remains highly uncertain, as does the impact on the distribution of UTLS ozone and other tracers. This study examines the response of the NH summertime monsoon anticyclones and UTLS ozone to the abrupt increase in E CO₂ forcing using output from a suite of coupled ocean–atmosphere general circulation model simulations. These models show an equatorward shift of the Asian summer monsoon anticyclone, a weakening of the North American summer monsoon anticyclone, and a stronger westerly flow penetrating deep into the tropics above the Pacific Ocean and North America. We use additional idealized experiments from atmosphere-only general circulation models with prescribed SSTs and sea ice concentration to isolate the direct atmospheric radiative effects from ...