Global Warming Will Leave Different Fingerprints on Global Subtropical Anticyclones

Typography

Subtropical anticyclone is an essential component of the atmospheric circulation in the subtropics, and it is responsible for the formation of subtropical monsoons and deserts. There are two subtropical anticyclones in the subtropical northern hemisphere in boreal summer, and three subtropical anticyclones in the subtropical southern hemisphere in austral summer. These five summertime subtropical anticyclones are all located at the lower troposphere over the subtropical oceans.

Subtropical anticyclone is an essential component of the atmospheric circulation in the subtropics, and it is responsible for the formation of subtropical monsoons and deserts. There are two subtropical anticyclones in the subtropical northern hemisphere in boreal summer, and three subtropical anticyclones in the subtropical southern hemisphere in austral summer. These five summertime subtropical anticyclones are all located at the lower troposphere over the subtropical oceans.

To assess the possible responses of the subtropical anticyclones to greenhouse gases (GHG) forcing, Dr. HE Chao from China Meteorological Administration, and Drs. WU Bo, ZOU Liwei and Prof. ZHOU Tianjun from CAS Institute of Atmospheric Physics adopted multiple metrics and obtained robust results. Coupled models under GHG forcing show that the subtropical anticyclones over North Pacific, South Atlantic and South Indian Ocean will become weaker in future under RCP8.5 scenario, whereas the subtropical anticyclones over North Atlantic and South Pacific will become stronger.

Continue reading at Institute of Atmospheric Physics - Chinese Academy of Sciences

Map: Projected future change of relative vorticity at 925 hPa. The black and white contours show the climatology for the 20th and 21st centuries. The shading shows the projected change by the ensemble mean of 30 models, and projected sign of change agreed by more than 70% of the models is stippled.

Credits: He et al, 2017