Natural variability of East Asian summer monsoon simulated by NCAR Cam3 model

Authors:

Gang Zeng ^*a,c, Wei-Chyung Wang ^b, Zhao-bo Sun ^a, Zhao-hui Lin ^c
a Key Laboratory of Meteorological Disasters of Ministry of Education, Nanjing University of Information Science & Technology, Nanjing, China 210044;
^b Atmospheric Science Research Center, State University of New York at Albany, Albany, New York State, U.S.A 12203;
^c International Center for Climate and Environmental Sciences, Institute of Atmospheric Physics,Chinese Academy of Sciences, Beijing, China 100029. 

Abstract:

Based on the 100-yr simulations from seasonal cycle global SST and sea ice driven by NCAR Cam3 atmospheric general circulation model, the natural variability of East Asian summer monsoon (EASM) in the internal atmosphere is investigated. Results suggest that the natural variability of EASM in the internal atmosphere displays 1) mainly distinct 3-7-yr interannual period and marked interdecadal variation; 2) in the year of weak EASM, sea level pressure (SLP) in Asian continent increases, with decreased SLP around Japan and in eastern Asian littorals; the 500 hPa height field exhibits negative anomalies over Europe, positive anomalies about the Caspian Sea and negative anomalies around Japan and in the Pacific area to  the east, thus leading to an EU-like teleconnection wavetrain and almost v.v. for the year of strong EASM. It is also found that the simulated EASM has a close relation to the EU-like teleconnection wavetrain at 500 hPa on a synchronous basis. 

Key words:

East Asian summer monsoon, natural variability, numerical simulation, interdecadal variation