CAJ | 학술논문

利用1980-2011年观测的降水和美国NCEP/NCAR大气再分析等资料，采用经验正交分解（EOF）和线性回归等统计方法，讨论了2011年发生在长江中下游地区春夏旱涝急转的成因。结果表明：2011年1-5月持续的La Nin?a事件导致西北太平洋副热带高压位置位于125°E以东，西北太平洋副热带高压西北侧的西南风伴随的水汽通量无法达到长江流域，从而导致2011年长江流域1-5月的持续性干旱现象。伴随La Nin?a的减弱，6月青藏高原的感热明显增强，诱发西北太平洋副热带高压自东向西北方向移动至110°E，引导西南风水汽向长江流域输送，而青藏高原对流的加强和向东移动与来自西北太平洋副热带高压西北侧的西南气流在长江中下游地区汇合，导致6月长江中下游地区降水的急剧增加，从而形成了2011年长江中下游地区春夏季的旱涝急转。
이용1980-2011년관측적강수화미국NCEP/NCAR대기재분석등자료，채용경험정교분해（EOF）화선성회귀등통계방법，토론료2011년발생재장강중하유지구춘하한로급전적성인。결과표명：2011년1-5월지속적La Nin?a사건도치서북태평양부열대고압위치위우125°E이동，서북태평양부열대고압서북측적서남풍반수적수기통량무법체도장강류역，종이도치2011년장강류역1-5월적지속성간한현상。반수La Nin?a적감약，6월청장고원적감열명현증강，유발서북태평양부열대고압자동향서북방향이동지110°E，인도서남풍수기향장강류역수송，이청장고원대류적가강화향동이동여래자서북태평양부열대고압서북측적서남기류재장강중하유지구회합，도치6월장강중하유지구강수적급극증가，종이형성료2011년장강중하유지구춘하계적한로급전。
Based on observed precipitation and the NCEP/NCAR reanalyzed datasets from 1980 to 2011,possible causes of abrupt turning from drought to flooding in the middle and lower reaches of Yangtze River valley (YRV) region during spring to early summer of 20 1 1 were discussed using methods of an EOF and a linear regression a-nalysis.The results indicate that the persistent La Nin?a events during January to May of 2011 maintain the 125°E eastward shift of western North Pacific subtropical high (WNPSH),thus the southwesterly moisture flux fails to reach the YRV region,which leads to the persistent drought events from January to May of 20 1 1 .However,sensi-tive heating flux enhances in the Tibetan Plateau (TP)with the decaying of La Nin?a in June,which induces a westward shift of WNPSH moving to 1 10°E from east to northwest and makes water vapor from southwesterly wind transporting to the YRV.Convection from the TP enhances and moves to east,and it meets southwest air flow from the northwest side of WNPSH in the middle and lower reaches of the YRV,which leads to increase precipita-tion sharply,and then it forms abrupt turning from drought to flooding in 20 1 1 .