天山山区及邻近地区夏季降水的环境场特征与涡度平衡

本文对天山山区及其邻近地区夏季降水过程的环境场特征、水热收支和涡度平衡做了诊断分析。结果表明，降水发生前的环境场有利于降水系统的发展。Ｑ１，Ｑ２和涡度平衡在降水发生前与降水期有一定的差异，降水期水热收支中起主作用的是水平平流项潜热和热基本上被冷平流所平衡；水汽的水平输送为降水的主要水汽来源，垂直输送也起一定的作用，涡度平衡中主要是水平平流累积的正涡度与散度项制造的负涡度相平衡，与副热带锋区上急流相

CHARACTERISTICS OF ENVIRONMENTAL FIELD AND VORTICITY BALANCE IN SUMMERPRECIPITATION PROCESSES OVER TIANSHAN MOUNTAIN AREA AND SURROUNDING AREAS

In this paper,diagnosis was carried out for characteristics of environmental field, heat and moisture budgets and vorticity balance in summer precipi- tation processes over Tiansban Mountain area and surrounding areas. The results show that characteristics of environmental field before precipitation occered is benefited of de- velopment of influencing system of precipitation. There are some differences of Q1,Q2 and vorticity balance during precipitation and before precipitation occcred. Horizon- tal advection play the main part in heat and moisture budgets during precipitation. Heating of latent heat was balanced enssentially by cold advection. Water vapour that precipitation required was transported mainly by horizontal advection. Pos- itive vorticity accumulated by horizontal advection was balanced with negative vorticity made by divergence term in vorticity balance. Nonline advection which is connected with jet of subtropical frontal zone occupies a main place in heat and moisture budgets and vorticity balance.