Open AccessCoupling of Convective Momentum Transport with Convective Heating in Global Climate Simulations
Author(s) -
Xiaoqing Wu,
Liping Deng,
Xuan Song,
Guangjun Zhang
Publication year - 2007
Publication title -
journal of the atmospheric sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.853
H-Index - 173
eISSN - 1520-0469
pISSN - 0022-4928
DOI - 10.1175/jas3894.1
Subject(s) - hadley cell , convection , intertropical convergence zone , equator , climatology , zonal and meridional , atmospheric sciences , momentum (technical analysis) , environmental science , climate model , latitude , geology , general circulation model , meteorology , physics , climate change , precipitation , oceanography , geodesy , finance , economics
The effects of convective momentum transport (CMT) on global climate simulations are examined in this study. Comparison between two sets of 20-yr (1979–98) integration using the NCAR Community Climate Model version 3 (CCM3) illustrates that the inclusion of CMT in the convection scheme systematically modifies the climate mean state over the equatorial region. The convective momentum tendencies slow down the equatorward flow at higher latitudes near the surface and weaken the equatorial convergence and convection. This reduces the convective heating and drying around the equator and produces an improved meridional distribution within the upward branch of the Hadley circulation. The major heating peak during the boreal winter is moved to south of the equator at about 10°S, which is closer to the heat budget residuals of the ECMWF reanalysis data. The responses of meridional wind to the reduced heating result in the secondary meridional circulation within the intertropical convergence zone.