CAJ | 학술논문

本文利用耦合了中国气象科学研究院双参数微物理方案的中尺度数值模式MM5,对2002年7月22～23日长江中游一次梅雨锋暴雨过程进行了人工缓减暴雨的冷云催化数值试验.在对降水云系多尺度结构进行正确模拟的基础上,采用增加人工冰晶的催化方法,对人工缓减暴雨的可能方法及原理进行研究.结果表明,不同催化方案得到比较稳定一致的结果,在云体成熟期大剂量持续催化的减雨效果最好,在3600km~2内减少雨量8.29×lO~6t,即为自然雨量的14.8%,雨量分布更为均匀,其中50mm以上降水范围由原来的190km~2缩减到60km~2.分析表明,催化增加的大量冰晶碰并过冷雨,使霰粒子浓度增大而平均尺度减小,导致霰落速减弱而小于上升运动,难于下落融化,造成雨水减小.在周围升速小的弱雨区,滞留的霰粒长大后仍能下落融化,引起地面少量增雨.本文所用催化方法在实际作业中具有技术可行性,并有重大潜在社会和经济效益,值得深入研究和试验.
본문이용우합료중국기상과학연구원쌍삼수미물리방안적중척도수치모식MM5,대2002년7월22～23일장강중유일차매우봉폭우과정진행료인공완감폭우적랭운최화수치시험.재대강수운계다척도결구진행정학모의적기출상,채용증가인공빙정적최화방법,대인공완감폭우적가능방법급원리진행연구.결과표명,불동최화방안득도비교은정일치적결과,재운체성숙기대제량지속최화적감우효과최호,재3600km~2내감소우량8.29×lO~6t,즉위자연우량적14.8%,우량분포경위균균,기중50mm이상강수범위유원래적190km~2축감도60km~2.분석표명,최화증가적대량빙정팽병과랭우,사산입자농도증대이평균척도감소,도치산락속감약이소우상승운동,난우하락융화,조성우수감소.재주위승속소적약우구,체류적산립장대후잉능하락융화,인기지면소량증우.본문소용최화방법재실제작업중구유기술가행성,병유중대잠재사회화경제효익,치득심입연구화시험.
A case of heavy rainfall during the Meiyu period of 22-23 July 2002 is simulated using mesoscale model MM5 coupled with the CAMS(Chinese Academy of Meteorological Sciences)microphysical scheme.Numerical ex-periments of adding ice crystals are conducted to study if there is any possibility to decrease the heavy rainfall. Sev-eral tests for different seeding times and different concentrations of seeding particles are designed.Results show that overseeding in the mature stage results in the most reduction of rainfall. In the region of 3600 km~2,rainfall is de-creased by 14.8%,which is 8.29×10~6t.The heavy rainfall area with precipitation over 50 mm decreases from 190 km~2 to 60km~2.After seeding with a large amount of ice crystals,graupel grows through the collection of ice crystal with supercooled rain water.This causes that the number concentration of graupel becomes larger and the mean di-ameter of graupel becomes smaller.The falling speed of graupel becomes smaller than the updraft and graupel can-not fall to the warm region to melt.This is one of the main reasons of decreasing surface rainfall While in the weak updraft region around the decreasing rainfall center,graupel retained in the cold area grows gradually,and then falls,which increases the rainfall in the weak precipitation region.The overseeding methods in this paper are able to be used technically in the practical field test,which is worthy to make further studies and tests.