Linear Response of the Global Atmosphere to Thermal Forcing during Northern Summer

[摘要] Linear responses of the stationary planetary scale disturbances to subtropical and trop-ical heat sources are investigated for summer northern hemisphere. The model with high vertical resolution is used. Its top is 80km. Zonal mean flows are assumed using FGGEIIIB data by ECMWF. If there are heat sources at 30°N and 10°N, the solutions agree well with observations. The wave of zonal wave number 1 propagates to 60°N. It has two maxima around 30°N and 60°N and minimum at 40°N. The wave of wave number 5 can propagate to 45°N and has only one maximum there.The results suggest that Indian Monsoon activities and heat sources over the Tibetan Plateau can affect on the stationary patterns in middle and high latitudes through poleward propagation of stationary Rossby waves even in summer. On the other hand, the meridional profiles of zonal flows significantly affect on whether the waves forced by heating at ITCZ can propagate northward or not.

[学科分类] 大气科学