NAME =  Eun-Jeong, CHA  
ORGANIZATION =  Center for CLimate System Research, University of Tokyo  
ADDRESS =  4-6-1, Komaba, Meguro-ku, Tokyo.Japan  
COUNTRY =  Japan  
PHONE =  +81-3-5453-3962  
FAX =  +81-3-5453-3964  
E-MAIL =  cha@ccsr.u-tokyo.ac.jp  
POSTER_ONLY =  no  
THEME =  T3  
DATE =  25-Jul-04-14:46:01  
ABSID = T3EC25Jul04144601 
TITLE = The characteristics and the causes of extreme rainfall events in August over Korea 
AUTHOR_1 = Masahide Kimoto 
INSTITUTION_1 = Center for Climate System Research, University of Tokyo 
AUTHOR_2 = Eun-Jeong, Lee 
INSTITUTION_2 = School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea  
AUTHOR_3 = Jong-Ghap, Jhun 
INSTITUTION_3 = School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea  
ABSTRACT =  We investigate the characteristics of precipitation and its extremes exceeding 80 mm/day in August over Korea in terms of temporal and spatial variatiosn. In addition, the possible causes of extreme rainfall events in seven years that have the most number of heavy rainfall events are suggested. The largest monthly mean rainfall and the most frequency of extreme rainfall events appear in August over Korea from 1973 to 2002. The notable increasing trend in both monthly rainfall and the frequency of extreme events are found in August. This increasing trend is mainly attributed by the seven heaviest years, 1987, 1993, 1995, 1998, 1999, 2000, and 2002.

   The effects of Typhoon and the large-scale circulation as the possible causes of the extreme rainfall in August are suggested. Among the seven heaviest years, in 1995, 1999, 2000, and 2002, the effect of Typhoon is important to the occurrence of heavy rainfall events in August. Though the total numbers of the occurrence of Typhoon are under the average from mid 1990s, the effects of Typhoon on the August rainfall over Korea are enhanced. The spatial distribution of the frequency of the heavy rainfall events in those years shows that the events are concentrated over the western coast of Korea due to the track of Typhoon. In addition, the spatial scale of the events is larger than that of the other heavies years, 1987, 1993, and 1998.

   The large-scale circulation has a more significant role in the extreme events in 1987, 1993, and 1998 rather than the role of Typhoon. From the analysis of large-scale ciculation, it is found that the heavy rainfall events in August are related to the circulation of both the midlatitudes and the tropics; the Eurasian (EU) pattern and the western North Pacific subtropical high (WNPSH), respectively.

Key words : extreme rainfall event, August, Korea, Typhoon, Eurasian pattern, western North Pacific subtropical high