Atmosphere (대기)

Korean Meteorological Society (한국기상학회)
권호 표지
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Classification of Intraseasonal Oscillation in Precipitation using Self-Organizing Map for the East Asian Summer Monsoon

동아시아 여름몬순 지수의 자기조직화지도(SOM)에 의한 강수량의 계절 내 진동 분류

  • Chu, Jung-Eun (Division of Earth Environmental System, Pusan National University) ;
  • Ha, Kyung-Ja (Division of Earth Environmental System, Pusan National University)
  • 추정은 (부산대학교 지구환경시스템학부 대기과학전공) ;
  • 하경자 (부산대학교 지구환경시스템학부 대기과학전공)
  • Received : 2011.05.13
  • Accepted : 2011.06.28
  • Published : 2011.09.30
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Abstract

The nonlinear characteristics of summer monsoon intraseasonal oscillation (ISO) in precipitation, which is manifested as fluctuations in convection and circulation, is one of the major difficulty on the prediction of East Asian summer monsoon (EASM). The present study aims to identify the spatial distribution and time evolution of nonlinear phases of monsoon ISO. In order to classify the different phases of monsoon ISO, Self-Organizing Map(SOM) known as a nonlinear pattern recognition technique is used. SOM has a great attractiveness detecting self-similarity among data elements by grouping and clustering such self-similar components. The four important patterns are demonstrated as Meiyu-Baiu, Changma, post-Changma, and dry-spell modes. It is found that SOM well captured the formation of East Asian monsoon trough during early summer and its northward migration together with enhanced convection over subtropical western Pacific and regionally intensive precipitation including Meiyu, Changma and Baiu. The classification of fundamental large scale spatial pattern and evolutionary history of nonlinear phases of monsoon ISO provides the source of predictability for extended-range forecast of summer precipitation.

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References

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