定常条件下感热和地形影响的Rossby波

通过在非绝热准地转线性模式中引入波动形式解,并确定适当的定解条件,用正交模方法求得了感热波的波动解。结果表明由于感热加热集中于近地层附近,其波动解具有与山脉波类似的波动垂直结构,波动等位相线随高度向西倾斜,波动能量向上传播。对NCEP/NCAR资料的分析验证了理论推导结果的合理性。大尺度大气定常波随纬度和季节有明显变化。热带地区定常波主要受潜热加热影响,副热带地区大气波动常表现为地形、潜热和感热加热的综合效应,而中纬度地区大气定常波则主要由地形和感热加热决定。

STEADY WAVE LIKE SOLUTION OF THE ROSSBY WAVE WITH SENSIBLE HEATING AND TOPOGRAPHIC EFFECTS

Based on the classical atmospheric wave theory, we derive the wave-lik e solution of the steady Rossby wave with sensible heating and topographic forci ng by the normal mode method. Results show that since the sensible heating is confined in the surface layer, the equal phase lines of its solution tilt westward with increasing height and thereby the wave energy transfers upward, and the ve rtical structure of the solution of sensible heating wave therefore presents sim ilar to that of mountain wave. Using the NCEP/NCAR reanalysis data, features of the large-scale steady atmospheric waves along three latitudes, i.e., 15°N, 30 °N , and 45°N, in East Asia are further investigated to verify the rationality of t his solution. The large-scale steady waves vary obviously with season and latit u de change. In the tropics, latent heating is the key factor of the formation of atmospheric steady waves. In mid latitudes, both sensible heating and topograph y can generate the steady waves. In the subtropics, however, large -scale steady waves depend on the combination of topography, latent heating, as well as sensibl e heating.