CAJ | 학술논문

利用美国国家海洋和大气管理局（NOAA）向外长波辐射（OLR）月平均资料、欧洲中期数值预报中心（ECMWF） ERA-interim 月平均再分析资料、全球降水气候中心（GPCC）降水资料及中国气象局国家气象信息中心提供的中国756站逐日观测资料，通过定义一个海洋性大陆区域对流强度指数（I OLR ），分析了海洋性大陆区域（Maritime Continent，MC）近35年来11月—次年1月对流活动特征，并揭示了11月—次年1月海洋性大陆区域对流活动强度的年际变化与同期云贵高原降水的联系。结果表明：海洋性大陆区域对流活动除了有逐渐增强的趋势外，还存在3—5 a 及8—10 a 的振荡周期。当海洋性大陆区域对流活动偏弱（强）时，云贵高原西部降水偏少（多），东部降水偏多（少），高原东西部之间降水分布差异加大（减小）。引起云贵高原降水异常的原因有3个方面：一是在海洋性大陆区域与云贵高原间存在显著的异常垂直环流圈，当下沉（上升）支位于海洋性大陆区域时，上升（下沉）支将位于云贵高原地区。而云贵高原地形可能对云贵高原降水异常在东南部和西北部的差别的产生存在影响；二是海洋性大陆区域在对流层低层的辐散和对流层上层的辐合运动为热带和高原以东地区提供了异常的位涡强迫，直接导致对流层低层南海—孟加拉湾地区异常反气旋和对流层上层位于中国南方的异常气旋性环流的产生；三是由于海洋性大陆区域辐散运动作为位涡制造而激发的位涡扰动的能量从热带地区向云贵高原及其东侧频散并辐合，对云贵高原上空扰动异常的维持起到了重要作用。这些结果有利于深刻理解云贵高原冬季降水异常的形成机理以及为寻找降水异常预测因子提供了有用的线索。
이용미국국가해양화대기관리국（NOAA）향외장파복사（OLR）월평균자료、구주중기수치예보중심（ECMWF） ERA-interim 월평균재분석자료、전구강수기후중심（GPCC）강수자료급중국기상국국가기상신식중심제공적중국756참축일관측자료，통과정의일개해양성대륙구역대류강도지수（I OLR ），분석료해양성대륙구역（Maritime Continent，MC）근35년래11월—차년1월대류활동특정，병게시료11월—차년1월해양성대륙구역대류활동강도적년제변화여동기운귀고원강수적련계。결과표명：해양성대륙구역대류활동제료유축점증강적추세외，환존재3—5 a 급8—10 a 적진탕주기。당해양성대륙구역대류활동편약（강）시，운귀고원서부강수편소（다），동부강수편다（소），고원동서부지간강수분포차이가대（감소）。인기운귀고원강수이상적원인유3개방면：일시재해양성대륙구역여운귀고원간존재현저적이상수직배류권，당하침（상승）지위우해양성대륙구역시，상승（하침）지장위우운귀고원지구。이운귀고원지형가능대운귀고원강수이상재동남부화서북부적차별적산생존재영향；이시해양성대륙구역재대류층저층적복산화대류층상층적복합운동위열대화고원이동지구제공료이상적위와강박，직접도치대류층저층남해—맹가랍만지구이상반기선화대류층상층위우중국남방적이상기선성배류적산생；삼시유우해양성대륙구역복산운동작위위와제조이격발적위와우동적능량종열대지구향운귀고원급기동측빈산병복합，대운귀고원상공우동이상적유지기도료중요작용。저사결과유리우심각리해운귀고원동계강수이상적형성궤리이급위심조강수이상예측인자제공료유용적선색。
Based on the monthly mean outgoing long wave radiation (OLR)data from NOAA,the ERA-interim reanalysis from ECMWF,the precipitation data from GPCC and station precipitation data from NMC,by defining a convection intensity index (I OLR )in the Maritime Continent region (MC hereafter),we have investigated the characteristics of convections over MC and the relationships between the convection variations over MC and the precipitation anomalies over the Yunnan-Kweichow Plateau (Y-K Plateau hereafter)in the period of late fall to earlier winter including November,December,and January from 1979 to 2013.It is found that the intensity of convections in MC increases linearly during the past 3 decades.Besides this interdecadal change,the convections in MC change with periodicities of 3-5 years and 8-10 years.When the I OLR is positive (negative), i.e.,the convections region are weaker (stronger)in MC,the precipitation is found to be less (more)than normal in the west of the Y-K Plateau and simultaneously more (less)in the east.There are three mechanisms responsible for the precipitation a-nomaly in the Y-K Plateau.Firstly,the anomalous vertical circulation between MC and the Y-K Plateau connects the downdraft (updraft)over MC and updraft (downdraft)over the plateau.It seems that the terrain may play a role in inducing the precipita-tion anomaly differences between the southeastern and the northwestern parts of the Y-K Plateau.Secondly,the divergent wind components in both the lower and upper troposphere as a potential vorticity source directly induce the vorticity anomalies in the lower latitudes and in the southern part of China.Thirdly,the anomalous potential vorticity in the tropical region north of MC perturbs the atmosphere,dispersing wave energy from the tropical region northward into the Y-K Plateau,facilitating the ma-intenance of an anomalous cyclonic circulation there,and inducing rainfall anomalies in the Y-K Plateau.These results are help-ful for us to better understand the formation mechanisms of precipitation anomaly over the plateau and for us to find some use-ful clues to precipitation prediction there in wintertime.