Late 21st Century Monsoon Precipitation Projected in CMIP5June-Yi Lee and Bin Wang (Climate Dynamics, in press)

Changes in monsoon precipitation for (a) boreal winter (DJF) and (b) summer (JJA) in CMIP5 from 1980–2005 to 2070–2095 under the RCP4.5 future scenario. Stippling: areas where magnitude of the MME exceeds statistical significance, with present-day wet regions outlined in red and dry regions in grey.

The CMIP5 multi-model ensemble (MME) of the four best models projects the following precipitation changes for the last part of the 21st century under the RCP4.5 scenario: Mean and range of the Global monsoon as well as percentage of local summer rainfall to increase significantly over both land and ocean. Northern Hemisphere (NH) monsoon to begin earlier and withdraw later. Asymmetry in monsoon rainfall between eastern-western hemispheres to increase. NH precipitation to increase about 0.25 to 0.3 mm/day by 2100 (1.3% per Kelvin global mean temperature increase); Southern Hemisphere (SH) precipitation to decrease slightly. Land monsoon domain over Asia to expand westward by 10.6%. The significant projected increase in NH monsoon precipitation is due to increased temperature difference between the NH and SH, resulting in a significant strengthening of the Hadley circulation and atmospheric moistening against a stabilization of the troposphere.

a) DJF b) JJA