1. Trend and Variability of East-Asian Precipitation: Linkage to Sea Surface Temperatures Fanglin Yang Environmental Modeling Center National Centers for Environmental Prediction NOAA 32 nd Climate Diagnostic and Prediction Workshop COAPS/FSU, October 22-27, 2007 Acknowledgment: This work was support by the NASA Modeling, Analysis and Prediction program while the author worked with William Lau at GFSC/NASA.

2. Possible causes: 1.South Asian black carbon emission 2.Climate regime shift 3.Global warming 4.Shift of Africa-North China teleconncection 5.SST trend

6. South China Central China North China

9. Interannual < 7 years Inter-Decadal >7 years MAM JJA

10. Questions? To what extent can the observed precipitation variability can be explained by SST variability? Does the precip-SST relation at the interannual timescale differ from that at the inter-decadal timescale?

11. Interannual Variability Single Value Decomposition (SVD) applied to 7- year high-pass filtered precipitation and SSTs

12. SSTPrecip MAM

13. SSTPrecip JJA

15. SST Variance Precipitation Variance SST- Precipitation Co-Variance Correlation (PC_sst, PC_precip) MAM SVD 1 31%27% 0.57 SVD 2 11%15%14%0.64 JJA SVD 1 43%10%24%– 0.77 SVD 2 7%17%13%0.76

16. SST_PCPrecip_PC JJA, Regressions of wind850 and Z700 to PCs JJA Climate, 1951-1998, NCEP R1 SVD Modes

17. SST_PC Precip_PC MAM

18. Decadal Variation and Trend

19. SST Interannual Mode

20. Rainfall Interannual Mode Projection of Obs to SVD mode Area-Mean Rainfall

21. Conclusion Interannual Variability Precipitation over South China in MAM and North China in JJA  ENSO mode of SSTs Precipitation over central China in both MAM and JJA season  SST in warm pool and northern Indian ocean; Features of the anomalous 850- hPa winds and 700-hPa geopotential height corresponding to these modes support a physical mechanism that explains the causal links between the modal variations of precipitation and SSTs. Trend and decadal variation Upward South China MAM precipitation and downward JJA North China precipitation  warming trend of the ENSO-like mode. Upward JJA central China precipitation  warming trend of SSTs over the warm pool and Indian Ocean. Downward MAM South China precipitation  downward central North Pacific SSTs (less robust)