CAJ | 학술논문

利用 NCEP／NCAR 再分析大气环流资料、哈得来中心海温资料、中国700多站降水资料以及全球格点降水资料，详细分析了中国南方冬季降水异常的特征，并揭示了其所对应的欧亚大气环流和东亚冬季风异常与 ENSO 事件的联系，以及ENSO 暖／冷位相对其影响的非对称性。研究进一步证明了厄尔尼诺是导致中国南方冬季降水偏多的重要外强迫因子，并指出拉尼娜对中国南方冬季降水的影响表现出明显的年代际变化特征。1980年之前的拉尼娜年冬季，东亚冬季风显著偏强，东亚大槽偏深，西北太平洋副热带高压偏弱偏东，中国南方受一致偏北风影响，气温偏低，降水偏少，多表现为冷干的气候特征。但1980年之后的拉尼娜年冬季，东亚大槽偏弱，印缅槽偏强，同时在菲律宾以西激发出异常气旋性环流，使得异常偏东风控制中国南方，有利于热带水汽输送增强，因此降水偏多。同时，1980年之后的拉尼娜事件还使得东亚副热带西风急流偏强偏北，中国南方处于急流入口区的右侧，通过二级环流使得中国南方上空的上升运动偏强，有利于降水偏多。因此，1980年之后的拉尼娜年冬季，中国南方易表现出冷湿的气候特征，有时也容易发生低温雨雪冰冻灾害。进一步分析表明，1980年以后拉尼娜成熟期海温异常空间分布型的变化，以及北半球大气环流的年代际变化可能是导致拉尼娜对东亚大气环流的影响在1980年之后发生变化的重要原因。
이용 NCEP／NCAR 재분석대기배류자료、합득래중심해온자료、중국700다참강수자료이급전구격점강수자료，상세분석료중국남방동계강수이상적특정，병게시료기소대응적구아대기배류화동아동계풍이상여 ENSO 사건적련계，이급ENSO 난／랭위상대기영향적비대칭성。연구진일보증명료액이니낙시도치중국남방동계강수편다적중요외강박인자，병지출랍니나대중국남방동계강수적영향표현출명현적년대제변화특정。1980년지전적랍니나년동계，동아동계풍현저편강，동아대조편심，서북태평양부열대고압편약편동，중국남방수일치편북풍영향，기온편저，강수편소，다표현위랭간적기후특정。단1980년지후적랍니나년동계，동아대조편약，인면조편강，동시재비률빈이서격발출이상기선성배류，사득이상편동풍공제중국남방，유리우열대수기수송증강，인차강수편다。동시，1980년지후적랍니나사건환사득동아부열대서풍급류편강편북，중국남방처우급류입구구적우측，통과이급배류사득중국남방상공적상승운동편강，유리우강수편다。인차，1980년지후적랍니나년동계，중국남방역표현출랭습적기후특정，유시야용역발생저온우설빙동재해。진일보분석표명，1980년이후랍니나성숙기해온이상공간분포형적변화，이급북반구대기배류적년대제변화가능시도치랍니나대동아대기배류적영향재1980년지후발생변화적중요원인。
Using multiple datasets,this paper analyzes the characteristics of winter precipitation over southern China and its as-sociation with warm and cold phases of El Ni~no-Southern Oscillation during 1948-2011.The study proves that El Ni~no is an important external forcing factor resulting in above-normal winter precipitation in southern China.The study also reveals that the impact of La Ni~na on the winter precipitation in southern China has a decadal variability. <br> During the winter of La Ni~na before 1980,the East Asian winter monsoon is stronger than normal with a deeper trough o-ver East Asia,and the western Pacific subtropical high weakens with its high ridge retreating more eastward.Therefore,a-nomalous northerly winds dominate over southern China,leading to a cold and dry winter.During La Ni~na winter after 1980, however,the East Asian trough is weaker than normal,unfavorable for the southward invasion of the winter monsoon,with the India-Burma the East trough intensified,and the anomalous low-level cyclone excited by La Ni~na located to the west of the Philippines.Therefore,anomalous easterly winds prevail over southern China,which increases moisture flux from the tropical oceans to southern China.Meanwhile,La Ni~na after 1980 may lead to an enhanced and more northward subtropical westerly jet over East Asia in winter.Since southern China is rightly located on the right side of the jet entrance region,anomalous ascend-ing motion dominates there through the secondary vertical circulation,favoring more winter precipitation in southern China. Consequently,a cold and wet winter,sometimes with snowy and icy weathers,would occur in southern China during La Ni~na winter after 1980.Further analyses indicate that the change in the spatial distribution of sea surface temperature anomaly dur-ing the La Ni~na mature phase,as well as the decadal variation of the Northern Hemisphere atmospheric circulation,would be the important reasons for the decadal variability of the La Ni~na impact on the atmospheric circulation in East Asia and winter precipitation over southern China after 1980.