Authors: KiSeon Choi IlJu Moon
Publish Date: 2014/10/23
Volume: 122, Issue: 1-2, Pages: 353-363
Abstract
Since a tropical cyclone TC usually accompanies a large amount of rainfall it is estimated that average amounts of rainfall in summer increase in Northeast Asia NA when the genesis of TC in the western North Pacific WNP is frequent However the present study found a negative correlation between TC genesis number in summer over the WNP and the amount of summer rainfall over the midlatitudes of NA from 1980 to 2009 The results of the analysis reveal that in a positive TC genesis phase years in which TCs occur more frequently than on average an anomalous cyclone forms over the WNP which generates anomalous cold and dry northeasterly winds in the midlatitudes of NA resulting in reduction of rainfall In comparison in a negative TC genesis phase years in which TCs occur less frequently than on average a large anomalous anticyclone develops over the western Pacific which generates anomalous warm and humid southwesterly winds resulting in increase of rainfall in the same region The comparisons of the TC tracks between the two phases also reveal that in both phases the TC passage number is rather low in the midlatitudes of NA regardless of TC activities over the WNP This suggests that TC number does not greatly affect the total amount of summer rainfall in NA instead a largescale atmospheric circulation forming favorable unfavorable rainfall conditions in the negative positive TC genesis phase controls the summer rainfall in that area
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