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Diversity of the Coupling Wheels in the East Asian Summer Monsoon— The great c hallenge of summer rainfall forecast in China. Congwen Zhu With co-authors: B. Liu, K. Xu, K. Liu and N. Jiang Chinese Academy of Meteorological Sciences, Beijing 100081 E-mail:zhucw@cma.gov.cn ; Tel.68407544.
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Diversity of the Coupling Wheels in the East Asian Summer Monsoon—The great challenge of summer rainfall forecast in China • Congwen Zhu • With co-authors: B. Liu, K. Xu, K. Liu and N. Jiang • Chinese Academy of Meteorological Sciences, Beijing 100081 • E-mail:zhucw@cma.gov.cn;Tel.68407544
East Asian Summer Monsoon East Asian summer monsoon averaged 1981-2010
Seasonal and intraseasonal variations of EASM Zhu et al., Sci China Earth Sci,2011 Song et al.,J.Climate,2016
Outline • Background • Dominant modes of EASM on interannual time scale • Diversity of the coupling wheels in EASM • Earlier signals in the SST anomaly • Summary
Data and methods • Data: • Atmospheric components with 2.52.5 in resolution, provided by the NCEP/DOE R2 reanalysis (Kanamitsu et al. 2002); • 160 in suite monthly precipitation in China, and the global OI SST derived from the NOAA during 1979-2015. • Methods: • The principal component analysis (PCA, Obukhov,1947) and the multi-variant EOF (MV-EOF) analysis (Wang et al., 2008); • Potential vorticity (Hoskins,1985) ; • To focus on the interanual time scale, all linear trend have been removed form the anomalies before analysis.
MV-EOF analysis of winds and rainfall anomalies (1979-2015) MV-EOF1 MV-EOF2 Boreal summer; JJA mean
K-means cluster analysis of Three circulation indices1979-2015 (37 years) Circulation indices Rainfall anomalies
Outline • Background • Coupling wheels of East Asian summer monsoon • Diversity of the monsoon coupling • Earlier signals in the SST anomaly • Summary
Impacts of ENSO on the EASM Xie S-P, Kosaka Y, Du Y, Hu KM, Chowdary JS, Huang G. 2016. Indo-Western Pacific Ocean Capacitor and Coherent Climate Anomalies in Post-ENSO Summer: A Review. Adv. Atmos. Sci. 33: 411–432
North Atlantic triple and dipole modes (EOF analysis) NATM NADM
Earlier signals of circulation index in the SSTA anomalies MCI SAHI WPAI
Summary Diversity Coupling wheels of EASM 24 7 6