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24 March 1991, Volume 10 Issue 1   
  • DIAGNOSTIC ANALYSES OF A SUMMER VORTEX OVER QINGHAI-XIZANG PLATEAU FOR 29-30 JUNE 1979
  • Luo Siwei;Yang Yang;Lu Shihua
  • 1991 Vol. 10 (1): 1-12. 
  • Abstract ( ) PDF (855KB) ( )
  • In this paper a case study of development mechanism of a summer vortex in Qinghai-Xizang Plateau had been made for 00 UTC 29 through 12 UTC 30 June 1979. From view point of energy, by using apparent heat source and apparent moist sink equations used by Kou and Anthes and energy equations used by T. Nitta, a detailed diagnostic analysis about it had been performed. The results show that the surface eddy flux of sensible heat and latent heat due to cumulus convection and disturbance α( Q 1- Q 2) contributed to the development of the vortex substantially in which the surface evaporation plays a little role.The rainfall of vortex is convective whose moisture comes from the convergence below 500 hPa.The analysis of energy transformation shows that in the young and mature stage of vortex its energy mainly comes from the diabatic heating α Q 1 and takes the following form as CISK in the low latitude:α Q 1E→K.The most of diabatic heating comes from the vertical eddy flux of surface sensible heat due to cumulus convection and disturbance.Prior to the formation of vortex and in its last stage the developing mechanism is like baroclinic instability in the atmosphere of midlatitude and takes the following energy transformation form: E→E→K. At this time the α Q 1 plays a little role.