SIMULATION KOREAN SUMMER MONSOON RAINFALL WITH NCAR REGIONAL CLIMATE MODEL - Advances in Geosciences - page 17

SIMULATION KOREAN SUMMER MONSOON RAINFALL
WITH NCAR REGIONAL CLIMATE MODEL
G. P. SINGH ∗,† ,JAI-HOOH †,§ and JIN-YOUNG KIM †
∗ Department of Geophysics, Banaras Hindu University, Varanasi, India
† Department of Environment and Atmospheric Sciences
Pukyong National University, Busan, South Korea
§ [e-mail]
Some of the important characteristics of Korean summer monsoon circulations
and rainfall are examined using the NCAR Regional Climate Model (RegCM3).
RegCM3 has been simulated at 27 km horizontal resolution over the east Asia
domain for the period from January to December in 2002. The important
features of wind and temperature at lower and upper levels over east Asia
and precipitation simulated by the model over South Korea are examined in
details for different convective parameterization schemes namely, mass flux, a
Kuo-type and Emanuel schemes. The monsoon circulation features simulated
with RegCM3 are compared with those of the NCEP/NCAR reanalysis and
the simulated Korean summer monsoon rainfall (KMR) is validated against
the observations from Korea Meteorological Administration (KMA). Valida-
tion of simulated precipitation with KMA shows that the use of the Emanuel
scheme is more close to the KMA. Characteristic features of the intra-seasonal
quasi-biweekly (10-20 days period) and the Madden-Julian (30-60 days period)
oscillations have been investigated. Results of intra-seasonal oscillation also
indicate that the use of Emanuel convective scheme yields results close to the
KMA. Results from wavelet analysis show that the high precipitation in 2002
may be associated with prominent 30-60 days oscillation during the month of
August.
1. Introduction
Some of the studies, mainly by Chinese scientists, 1 have mentioned that
many differences exist between the monsoon circulations over south and
east Asia. This fact suggests that the main component of the east Asian
monsoon is likely to be different from the south Asian monsoon systems.
Therefore, Asian monsoon systems can be divided into two subsystems
namely, south and east Asian monsoons, which are independent to each
other. The east Asian summer monsoon system exhibit a large spatial and
temporal variability. Best example is a recent case of excess summer mon-
soon rainfall (KMR) of 2002 over South Korea. A prolonged period of
rain and showers occurred from 5 to 18 August 2002 over South Korea
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