Analysis Of The Macro And Micro-Physical Characteristics Of Stratiform Clouds In NingXia

The shortage of fresh water resources has become a serious problem whichgreatly hinders the sustainable development both regional and national economy.Precipitation enhancement is one of the effective ways to alleviate drought byexploring and utilizing the cloud water resource. Macro and microphysicalcharacteristics of altostratus without stratocumulus are analyzed based on dataset ofairborne observations in Ningxia from May to September between 1978 and 1990.The results show:(1) The cloud base of precipitating stratus without stratocumulus is a littlehigher than that with stratocumulus and the concentration of cloud droplets spectralof small particles is a little higher. The concentration of big droplets in warm layer ishigher than that in cold layer, which can provide a certain big droplets forcoagulation growing of cloud droplets and multiplication of ice crystals and ispropitious to the formation of precipitation.(2) The vertical distribution of liquid water content has several peak values, themax value lies in the middle-and-ender part, which is propitious to the coagulationgrowing of ice and snow crystals.(3) Ice crystals spectral of altostratus assumes a monotonous fall in the mass,and the content of snow crystals reaches maximum values at the scale of 0.3-0.6mm.The preponderant shapes of crystals are spatial dendrite, prismatic and acicularmainly. Using M-P distribution to fitting snow crystals spectral, of which coefficientN₀ is 0.132, coefficientλis 2.681 and related coefficient r is 0.975, and the fittingprecision of M-P distribution is superior to theΓfunction N(r)=ar²exp(-br).