NAME =  Akio Kitoh  
ORGANIZATION =  Meteorological Research Institute  
ADDRESS =  1-1 Nagamine, Tsukuba, Ibaraki 305-0052  
COUNTRY =  Japan  
PHONE =  81-29-853-8594  
FAX =  81-29-855-2552  
E-MAIL =  kitoh@mri-jma.go.jp  
POSTER_ONLY =  no  
THEME =  T4  
DATE =  23-Jul-04-17:21:55  
ABSID = T4AK23Jul04172155 
TITLE = ENSO-Monsoon Relationship in a 1000-yr MRI-CGCM Simulation 
AUTHOR_1 = A. Kitoh 
INSTITUTION_1 = Meteorological Research Institute 
PRESENTER = AUTHOR_1 
ABSTRACT = The interannual variability of the Indian summer monsoon rainfall and its close relation with 
ENSO is known (drought conditions over India accompany warm ENSO events and vice versa), 
but recent observation suggests a weakening of this ENSO-monsoon relationship and a 
possible link to global warming is suggested. Here we analyze ENSO-monsoon relationship in 
a 1000-year control simulation of the MRI coupled GCM (MRI-CGCM2.2, T42L30). An overall 
correlation between the JJA Nino3.4 SST and the JJA Indian monsoon rainfall is -0.39 with 
reasonable circulation characteristics associated with model ENSO. Simulated ENSO-monsoon 
relationship reveals long-term variations from -0.71 to +0.07 in moving 31-year windows. 
The poor-correlation periods coincide with periods when the Indian monsoon rainfall is 
above the long-term average, SST is warmer over the eastern Indian Ocean and the western 
Pacific, and convection center is located more westward. It is suggested that the magnitude 
of mean monsoon rainfall is more important than that of Nino3.4 SST on ENSO-monsoon 
relationship.