过冷云风洞中初始冰晶的初步研究  

PRELIMINARY STUDIES ON THE INITIAL ICE CRYSTALS IN SUPERCOOLED CLOUD TUNNEL

作　　者：周筠君[1] 龚乃虎[1] 

机构地区：[1]中国科学院兰州高原大气物理研究所,甘肃省兰州市730000

出　　处：《高原气象》1993年第4期442-449,共8页Plateau Meteorology

基　　金：国家自然科学基金资助项目

摘　　要：本文着重研究了在过冷云风洞中,温度为-4——16℃,含水量为1.4gm^(-3),爆泡后增长45s的初始冰晶的一些特性。结果表明:(1)初始冰晶质量在-4——13℃有两个峰值,它们是-5.7℃时的1.8×10^(-8)g与-11.4℃时的6.3×10^(-8)g,而在-8.4℃和-13.0℃时出现的极小值分别为2×10^(-9)g和5×10^(-9)g.(2)初始冰晶的浓度值随着温度的降低出现三个递减的峰值,它们分别是-4.2℃时的1.30×10~7个/cm^3,-7.6℃时的7.80×10~6个/cm^3和-13.80℃时的4.54×10~6个/cm^3。(3)聚合率峰值出现在-8℃,其值为12/30。(4)在扩散增长阶段冰晶基面上6个轴a_(1-6)在由中心指向外沿方向上被吸收的水分子条件完全相同,当X_(CBal-6)>X_(CPal-6)时,初始冰晶则为规则板状;当X_(CBal-6)<X_(CPal-6)时,初始冰晶为规则柱状。This paper describes some characteristics of initial ice crystals whose growth time is within 45 s at a liquid water content of 1.4 gm-3 between -4℃ and -16 ℃ in a supercooled cloud tunnel. The results show that: (1) There are two maximum mass values of the initial ice crystals between -4℃ and -13 ℃. One is 1.8 ×10-8 g at -5.7 ℃; the other is 6.3 ×10-8g at -11.4℃. There are two minimum values: 2× 10-9g at -8.4 ℃ , 5× 10-9g at -13.0℃ . (2) There are three maximum concentration values of the initial ice crystals. With the temperature lowering, the values are reducing. They are 1.30×107cm-3 at -4.2℃, 7.8 × 106cm-3 at -7.6℃ and 4.54 × 106cm-3 at -13.8 ℃, respectively. (3) The maximum aggregation rate of the initial ice crystals is 12 / 30 at -8 ℃. (4) The condition of the absorbed water molecules is same at six axes (a1-6) on the basal face of ice crystals at vapor diffusion growth stage. If XCBal-6 > Xcpal-6, regular plate crystals should grow; while XCBal-6 < XCPal-6, the initial ice crystals should be regular columnar crystals.

关 键 词：风洞 初始冰晶 冷云 

分 类 号：P426.63[天文地球—大气科学及气象学]