CAJ | 학술논문

在东亚地区,气溶胶是一个重要的气候强迫因子,它与季风之间的相互作用具有很强的不确定性,利用数值模式进一步研究气溶胶与季风降水之间的关系十分必要.本文采用 ICTP(International Centre for Theoretical Physics)第四代区域气候模式(RegCM4),通过两组对比试验和多年长期积分来研究气溶胶直接效应对中国夏季降水的影响.采用 TRMM 卫星降水资料和 MODIS 卫星气溶胶光学厚度资料评估了区域气候模式对中国夏季气溶胶和降水的模拟能力.总体来看,RegCM4能够再现我国夏季气候的主要特征,对我国夏季风环流和降水具有一定的模拟能力.气溶胶直接效应使得对流层温度降低,减弱了经向风环流,加强了位于20°N~30°N 范围的上升气流和35°N 以北地区的下沉气流,在我国东部引起了气旋式环流异常,并在110°E 附近产生了速度接近1 m·s-1的北风增强.总降水量的变化呈现出“南多北少”的趋势.在季风区,对流性降水和非对流性降水分别减少了0.05 mm·d-1和0.07 mm·d-1,其中非对流性降水的相对变化较大.从各类型降水的日变化可以看出,降水的减少主要发生在夜间至凌晨时段.
재동아지구,기용효시일개중요적기후강박인자,타여계풍지간적상호작용구유흔강적불학정성,이용수치모식진일보연구기용효여계풍강수지간적관계십분필요.본문채용 ICTP(International Centre for Theoretical Physics)제사대구역기후모식(RegCM4),통과량조대비시험화다년장기적분래연구기용효직접효응대중국하계강수적영향.채용 TRMM 위성강수자료화 MODIS 위성기용효광학후도자료평고료구역기후모식대중국하계기용효화강수적모의능력.총체래간,RegCM4능구재현아국하계기후적주요특정,대아국하계풍배류화강수구유일정적모의능력.기용효직접효응사득대류층온도강저,감약료경향풍배류,가강료위우20°N~30°N 범위적상승기류화35°N 이북지구적하침기류,재아국동부인기료기선식배류이상,병재110°E 부근산생료속도접근1 m·s-1적북풍증강.총강수량적변화정현출“남다북소”적추세.재계풍구,대류성강수화비대류성강수분별감소료0.05 mm·d-1화0.07 mm·d-1,기중비대류성강수적상대변화교대.종각류형강수적일변화가이간출,강수적감소주요발생재야간지릉신시단.
Aerosol is an important forcing influencing regional climate in East Asia.The interaction between aerosol and monsoon remains large uncertainty.It is necessary to further study the relationship between aerosol and monsoon rainfall.In this paper,two experiments and 5 years run were conducted to investigate the impact of aerosol direct effect on summer precipitation in China using the regional climate model version 4(RegCM4)from ICTP(In-ternational Centre for Theoretical Physics).Observational data including TRMM precipitation MODIS and aerosol optical depth were used to assess the performance of regional climate model in China.Generally,RegCM4 can reproduce the key feature of circulation and precipitation of summer monsoon in China.Our results show that,due to aerosol direct effect,troposphere temperature and meridional wind decreased.The updraft located between 20°N and 30°N and downdraft located on the north of 35°N were both intensified.There was a cyclonic circulation anomaly in eastern China,and there was about 1 m·s-1 northerly anomaly around 1 10°E.The total precipitation underwent a trend known as the southern flooding and northern drought.In the monsoon region,the convective precipitation decreased by 0.05 mm·d-1 and the non-convective precipitation decreased by 0.07 mm·d-1 .Note that the relative change of non-convective precipitation is larger than the change of the convective precipitation.As for the diurnal change of the precipitation,the reduction of precipitation occurred mainly during the night.