不同暴雨系统中潜热反馈作用的对比研究  

A COMPARATIVE STUDY ON EFFECTS OF LATENT HEAT RELEASE IN DIFFERENT HEAVY RAINFALL SYSTEMS

作　　者：潘在桃 王作述[1] 蔡则怡[1] 

机构地区：[1]中国气象科学研究院,中国科学院大气物理研究所

出　　处：《热带气象学报》1994年第2期161-171,共11页Journal of Tropical Meteorology

摘　　要：选择两种类型的暴雨个例用数值试验研究了不同条件下潜热反馈作用的大小，结果发现对于不同的暴雨系统，潜热作用差别很大，“６２６”（１９８６年６月２６日）京津冀暴雨中它使雨量增加约一倍，而“７５８”（１９７５年８月７日）河南暴雨却增加约四倍。此外，潜热反馈对高低空急流强度、位置，以及对上升运动大小的影响程度，也都是在“７５８”暴雨过程中较大。数值试验证明了造成这种差别的重要原因是高空急流强度和风速铅直切变。“６２６”暴雨靠近高空急流，高层风速及风速铅直切变大，释放的潜热不易积累，ＣＩＳＫ过程得不到充分发展，不利于暴雨的增强。“７５８”暴雨则与此相反。另外，试验还表明高低空急流和暴雨的相互影响，暴雨通常出现于低空急流左侧、高空急流右后侧这一观测事实，可能是潜热反馈的结果。至少是被它所加强。Based on numerical experiments of two heavy rainfall cases, the effects of latent heat release are studied compararively. It is found that the effects of latent heat feedback are considerably different in different heavy rainfall systems. In the heavy rainfall on June 26 , 1986 ( henceforth HR 8 6), the rainfall for the control experiment was doubled than that the where latent heat was removed in numerical experiment. But in the heavy rainfall Aug. 7 , 1975 (henceforth HR75), the rainfall was increased by a factor of 5 than that for the numerical experiment without lantent heat. In addition, the latent heat release had much stronger effects in the HR75 on intensity and location of upper-and-low-level jet and on upward vertical motion than that in HR86. It is demonstrated by numerical experiments that the difference of effects of latent heat in different heavy rainfall systems is due mainly to the wind speed of upper-and low-level jet and vertical Shear of wind speed. The HR86 was positioned in the environment with stronger upperlevel wind speed and vertical shear of wind speed because it was in the vicinity of the upper-level Jet. Therefore, it was difficult to accumulate the releasing latent heat and made the CISK mechanism in full acting. The environmental conditions for the HR75 were quite the reverse of that in the HR86. The numerical experiment indicates as well that the observational result that the heavy rainfall usually takeing place on the left of the low-level jet and the back-right of the upper-level Jet, is caused probably by the feedback of latent heat, at least intensified by it.

关 键 词：数值试验 暴雨 潜热反馈作用 对比研究 

分 类 号：P426.62[天文地球—大气科学及气象学]