Mechanism of the asymmetric monsoon transition as simulated in an AGCM

Zhuo Wang, C. P. Chang

Research output: Contribution to journalArticlepeer-review


Atmospheric general circulation model (AGCM) simulations are carried out to test a hypothesis (Chang et al.) for the asymmetric monsoon transition in which the maximum convection marches gradually from the Asian summer monsoon to the Asian winter monsoon during boreal fall but experiences a sudden transition in the reverse during boreal spring. In the control run, the AGCM is driven by the climatological mean sea surface temperature (SST) with a realistic annual cycle, and it reproduces the observed asymmetric monsoon transition. In the sensitivity test, the model is driven by a similarly realistic SST but whose annual cycle is symmetric. The northwestward march of the maximum convection in boreal spring becomes more gradual, resulting in an overall near-symmetric pattern for the monsoon seasonal transition. The AGCM simulations confirm the hypothesis that the atmospheric mass redistribution due to the different land-ocean thermal memories leads to a seasonally different horizontal convergence field and it facilitates the southeastward monsoon march in boreal fall, while it hinders the northwestward monsoon march in boreal spring, contributing to the asymmetric monsoon transition.

Original languageEnglish (US)
Pages (from-to)1829-1836
Number of pages8
JournalJournal of Climate
Issue number8
StatePublished - Apr 15 2008
Externally publishedYes

ASJC Scopus subject areas

  • Atmospheric Science


Dive into the research topics of 'Mechanism of the asymmetric monsoon transition as simulated in an AGCM'. Together they form a unique fingerprint.

Cite this