物理学报
物理學報
물이학보
2013年
6期
496-506
,共11页
张世轩%封国林?%赵俊虎
張世軒%封國林?%趙俊虎
장세헌%봉국림?%조준호
长江中下游%暴雨%“积成效应”%夏季降水
長江中下遊%暴雨%“積成效應”%夏季降水
장강중하유%폭우%“적성효응”%하계강수
middle and lower reaches of the Yangtze River%torrential rain%“Cumulative Effect”%summer precipita-tion
采用1960—2011年中国740站日降水观测数据,以长江中下游地区为切入点,提出暴雨“积成效应”这一概念,旨在将暴雨这一天气尺度强降水过程拓展为类似中长期天气尺度过程来考虑,研究它对季节尺度降水的贡献及影响.通过统计分析从持续时间(Ld)、控制面积(Ar)、降水贡献率(Qs)等三个角度建立暴雨“积成效应”概念及判定标准,并进一步结合上述指标建立暴雨“积成效应”强度指数.从这一角度出发,探讨长江中下游地区暴雨“积成效应”与夏季降水的时空对应关系,发现强度指数与同期夏季降水量的年际和年代际变化具有很好的一致性;强弱指数年合成分布以及指数与中国东部夏季降水相关系数的空间分布呈现出类似于中国东部夏季雨带的分布形式;而利用EOF分解对暴雨“积成效应”空间范围分类,发现其与该地区夏季降水具有相似的4种空间型,总体而言,长江中下游地区暴雨“积成效应”造成的降水极大地影响甚至决定整个夏季降水的多寡及空间分布.
採用1960—2011年中國740站日降水觀測數據,以長江中下遊地區為切入點,提齣暴雨“積成效應”這一概唸,旨在將暴雨這一天氣呎度彊降水過程拓展為類似中長期天氣呎度過程來攷慮,研究它對季節呎度降水的貢獻及影響.通過統計分析從持續時間(Ld)、控製麵積(Ar)、降水貢獻率(Qs)等三箇角度建立暴雨“積成效應”概唸及判定標準,併進一步結閤上述指標建立暴雨“積成效應”彊度指數.從這一角度齣髮,探討長江中下遊地區暴雨“積成效應”與夏季降水的時空對應關繫,髮現彊度指數與同期夏季降水量的年際和年代際變化具有很好的一緻性;彊弱指數年閤成分佈以及指數與中國東部夏季降水相關繫數的空間分佈呈現齣類似于中國東部夏季雨帶的分佈形式;而利用EOF分解對暴雨“積成效應”空間範圍分類,髮現其與該地區夏季降水具有相似的4種空間型,總體而言,長江中下遊地區暴雨“積成效應”造成的降水極大地影響甚至決定整箇夏季降水的多寡及空間分佈.
채용1960—2011년중국740참일강수관측수거,이장강중하유지구위절입점,제출폭우“적성효응”저일개념,지재장폭우저일천기척도강강수과정탁전위유사중장기천기척도과정래고필,연구타대계절척도강수적공헌급영향.통과통계분석종지속시간(Ld)、공제면적(Ar)、강수공헌솔(Qs)등삼개각도건립폭우“적성효응”개념급판정표준,병진일보결합상술지표건립폭우“적성효응”강도지수.종저일각도출발,탐토장강중하유지구폭우“적성효응”여하계강수적시공대응관계,발현강도지수여동기하계강수량적년제화년대제변화구유흔호적일치성;강약지수년합성분포이급지수여중국동부하계강수상관계수적공간분포정현출유사우중국동부하계우대적분포형식;이이용EOF분해대폭우“적성효응”공간범위분류,발현기여해지구하계강수구유상사적4충공간형,총체이언,장강중하유지구폭우“적성효응”조성적강수겁대지영향심지결정정개하계강수적다과급공간분포.
@@@@To expand the torrential rain which is a meso-and-micro scale weather process to a meso-and-long scale weather process, in this paper we choose the middle and lower reaches of the Yangtze River (MLRYZ) as a sample region, and propose the conception of“Cumulative Effect”of torrential rain (CETR) by using the daily precipitation observational data from 740 stations in China. On the statistical analysis of observations, we define CETR as the cumulation or superposition of many torrential rain processes, and three indexes, which are continuous time (Ld), control area (Ar) and precipitation contribution rate (Qs), which are used for explaining the conception of CETR. Then taking these three indexes into consideration, we establish the intensity index of CETR (BQDI) and study the relationship between the BQDI and the summer precipitation in MLRYZ. Results show that the interannual and interdecadal variations of BQDI are similar to those of summer precipitation in MLRYZ. The distribution of correlation coefficient between the BQDI and the summer precipitation in Eastern China and the composite analysis of representative years in BQDI show a large positive relation area in MLRYZ (significance test at the 95%level) and two large negative relation areas in North and South China (significance test at the 95%level), which reveals that the variations of BQDI not only correspond to the variations of summer precipitation in MLRYZ but also correlate with the distribution of summer precipitation in Eastern China to some extent. Besides, an empirical orthogonal analysis is performed on the frequency of torrential rain in MLRYZ, we find that the four major spatial modes of torrential rain are also similar to those of summer precipitation in MLRYZ. In conclusion, the precipitation caused by CETR greatly influences even determines the amount and distribution of summer rainfall, which is worth further investigating.
