海洋学报(中文版)
海洋學報(中文版)
해양학보(중문판)
ACTA OCEANOLOGICA SINICA
2014年
1期
86-97
,共12页
尚可%詹丰兴%何金海%祁莉
尚可%詹豐興%何金海%祁莉
상가%첨봉흥%하금해%기리
前期夏季%西太平洋暖池%热含量%江南春雨%可能机理
前期夏季%西太平洋暖池%熱含量%江南春雨%可能機理
전기하계%서태평양난지%열함량%강남춘우%가능궤리
preceding-summer%western Pacific warm pool%heat content%Spring Persistent Rain%possible mecha-nism
利用GODAS海洋温度资料、中国753站逐日降水资料以及NCEP/NCAR逐日再分析资料讨论了前期夏季西太平洋暖池热含量异常对江南春雨的影响,并通过高低层环流异常解释了其可能过程和机制。研究结果表明:(1)前期夏季暖池区热含量影响春雨的敏感海区位于9°~16°N,150°~166°E,与春雨强度呈显著反相关,前期夏季关键区热含量的显著偏低是春雨异常偏多的强信号。(2)多雨年和少雨年大气环流差值场与夏季暖池热含量(取反号)回归的次年春季大气环流形态基本一致。低层菲律宾海异常反气旋西北侧的暖湿西南气流输送及江南地区高层辐散抽吸运动是造成春雨偏多的直接原因。(3)关键区热含量在前期夏季的异常偏低使低层异常反气旋在其西北侧触发生成,并在菲律宾海附近持续存在(前夏至当年春季),春季引导强盛的西南气流向江南输送水汽;同时,热含量异常偏低在我国大陆东部激发出高层异常气旋并持续维持(前秋至当年春季),导致春季西风急流轴异常南压,高层形成异常辐散中心,形成强烈的抽吸作用,导致江南春雨显著偏多。前夏热含量显著偏高引起江南春雨偏少的过程则与之相反。
利用GODAS海洋溫度資料、中國753站逐日降水資料以及NCEP/NCAR逐日再分析資料討論瞭前期夏季西太平洋暖池熱含量異常對江南春雨的影響,併通過高低層環流異常解釋瞭其可能過程和機製。研究結果錶明:(1)前期夏季暖池區熱含量影響春雨的敏感海區位于9°~16°N,150°~166°E,與春雨彊度呈顯著反相關,前期夏季關鍵區熱含量的顯著偏低是春雨異常偏多的彊信號。(2)多雨年和少雨年大氣環流差值場與夏季暖池熱含量(取反號)迴歸的次年春季大氣環流形態基本一緻。低層菲律賓海異常反氣鏇西北側的暖濕西南氣流輸送及江南地區高層輻散抽吸運動是造成春雨偏多的直接原因。(3)關鍵區熱含量在前期夏季的異常偏低使低層異常反氣鏇在其西北側觸髮生成,併在菲律賓海附近持續存在(前夏至噹年春季),春季引導彊盛的西南氣流嚮江南輸送水汽;同時,熱含量異常偏低在我國大陸東部激髮齣高層異常氣鏇併持續維持(前鞦至噹年春季),導緻春季西風急流軸異常南壓,高層形成異常輻散中心,形成彊烈的抽吸作用,導緻江南春雨顯著偏多。前夏熱含量顯著偏高引起江南春雨偏少的過程則與之相反。
이용GODAS해양온도자료、중국753참축일강수자료이급NCEP/NCAR축일재분석자료토론료전기하계서태평양난지열함량이상대강남춘우적영향,병통과고저층배류이상해석료기가능과정화궤제。연구결과표명:(1)전기하계난지구열함량영향춘우적민감해구위우9°~16°N,150°~166°E,여춘우강도정현저반상관,전기하계관건구열함량적현저편저시춘우이상편다적강신호。(2)다우년화소우년대기배류차치장여하계난지열함량(취반호)회귀적차년춘계대기배류형태기본일치。저층비률빈해이상반기선서북측적난습서남기류수송급강남지구고층복산추흡운동시조성춘우편다적직접원인。(3)관건구열함량재전기하계적이상편저사저층이상반기선재기서북측촉발생성,병재비률빈해부근지속존재(전하지당년춘계),춘계인도강성적서남기류향강남수송수기;동시,열함량이상편저재아국대륙동부격발출고층이상기선병지속유지(전추지당년춘계),도치춘계서풍급류축이상남압,고층형성이상복산중심,형성강렬적추흡작용,도치강남춘우현저편다。전하열함량현저편고인기강남춘우편소적과정칙여지상반。
In this paper,the impact of the preceding-summer heat content over western Pacific warm pool on Spring Persistent Rain was analyzed based on the GODAS monthly mean sea temperature,China 753 stations precipitation and NCEP/NCAR daily reanalysis data.Possible process and mechanism were studied through anomalous circula-tion in upper and low level.Major results were:(1)Heat content over key region(9°~16°N,150°~166°E)in pre-ceding-summer was anti-correlated with the intensity of SPR.The significant low heat content in preceding-sum-mer strongly indicated surplus rainfall in spring.(2 )Difference field (rainy years minus drought years)in spring was consistent with spring circulation regressed by the heat content(opposite sign)in preceding-summer over warm pool.Direct causes of surplus rainfall were warm and wet southwest airflow in the low level,which located in northwest of the anomalous Philippine Sea anticyclone,and the pumping effect over Jiang Nan in upper level.(3) The anomalous low heat content over key region in preceding-summer induced low-level anomalous anticyclone in northwest,which persisted to current spring from preceding-summer.In spring,driven by the anomalous anticy-clone,powerful southwest flow carried abundant moisture to Jiang Nan.Meanwhile,anomalous cyclone of upper level over mainland of China was stimulated and lasted from preceding-autumn to current spring.The anomalous cyclone led to southward replacement of westerly j et axis and formation of the abnormal divergence center with in-tense pumping effect in the upper level,hence resulting in surplus rainfall in spring.Process of abnormally less rainfall in spring caused by anomalous high heat content in pre-summer was on the contrary.