1. The Seasonal Forecast of the Precipitation in China in the Summer of 2013 国际气候与环境科学中心 International Center for Climate and Environment Sciences Peng Jingbei The Institute of Atmospheric Physics(IAP), CAS

2. EASM System

3. IAP’s Climate Forecast ENSO forecast systems ENSO forecast systems CGCM Ensemble system AGCMs 2L 9L CGCM CCSM4.0 Statistical Methods ENSOSNOW Atmospheric Signal EASM Subtropical High precipitation Seasonal Forecast

4. IAP’s Forecast of ENSO IAP’s CGCM-Nino3 IAP’s Large-Size Ensemble ENSO Forecast System with Coupled Data Assimilation-Nino3.4 The ENSO-neutral will continue through the next several months.

5. IAP-2L-AGCM IAP-9L-AGCM CCSM4 Forecast of the Subtropical High Red- model’s long-term mean Green -prediction Blue-model’s long-term mean Red- prediction Blue-model’s long-term mean Red- prediction The subtropical high will be stronger than usual in summer of 2013

6. Forecast of EASM Snow Cover over the Tibetan Plateau (Provided by BCC/CMA) More Snow →Colder TP surface in spring and summer → Weaker temperature contrast → Weaker EASM Less snow Stronger EASM

7. Forecast of EASM The EASM Forecast Index U’ 200 in Feb 2013 +U’ 200 → the Jet shifted northward → less precipitation in the South Asia → land-sea contrast ↑ →stronger EASM (Zhang et al., 2003 ） The Drought monitor in Feb 2013 （ BCC/CMA ） Positive Correlation with EASM Index Stronger EASM

8. Precipitation Prediction （ Numerical Models ） 2L-AGCM9L-AGCM CCSM4

9. Composed Summer Rainfall Anomaly Percentage during the Decaying Phase of LN

10. Seasonal Forecast

11. Thank You

12. H500 Anomalies 2L 9L CCSM4

13. UV’850 2L9L CCSM4

14. CCSM4 Prediction Skills (Correlation Coefficients with NCEP Reanalysis Data)

15. East Asia Winter Monsoon (EAWM) +SSTAs in South China Sea(SCS) Frontier Stronger EAWM→-SSTAs in SCS in Winter→-SSTAs in Summer→Land-Sea Contrast↑→EASM Stronger （ Ji et al. ， 1997 ） SSTAs in DJF Index of EAWM Positive-Weaker SSTAs in JJA

16. Experiment of Ensemble Prediction of EASM Index of 2013 L2L9EAWMU’200 (FEB) 0.410.390.510.72 Ensemble Prediction Contradictions in Prediction of EASM of 2013 Correlations with Observation EASM Index during 1982-2012 L2L9CCSM4.0EAWMU’200 (FEB) -0.02-0.660.7WeakerStronger PredictorsPredictionExamination (Correlation) L2+L9+ EAWM+U’200 (FEB) -0.070.64 EAWM+U’200 (FEB) 0.180.71

17. 东亚地区的 2013 年夏季降水异常 mm/ day 预测意见： 2013 年我国夏季气候 环流：夏季风正常，副高 偏西偏北； 降水：我国南方降水偏少， 北方降水偏多；

18. A global atmospheric general circulation model developed at the Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS). (Zeng, 1987; Zhang, 1990; Liang, 1996; Bi, 1993) Horizontal Resolution: 4 o ×5 o ; Vertical Resolution: 9 levels, with a top at 10hPa. IAP9L-AGCM

19. Lower boundary conditions: Over the tropical Pacific region, the SSTA used in IAP9L-AGCM is the linear combination of observed SSTA in initial month and SSTA forecasted by IAP ENSO prediction system ： The initial atmospheric data and observed SSTA are from NCEP. The ensemble consists of seven integrations starting form last seven consecutive days in or Oct. (SSTA) t =  (t) [(SSTA) to ] Obs + [1-  (t)][ (SSTA) Fcst ] t Here,  (t) varies from 1.0 to 0.0 during the integration time Over other regions, SSTA is kept as the observed SSTA in initial month.

20. The Large-size Ensemble ENSO Forecast System with Coupled Data Assimilation Zheng, Zhu, et. al. GRL, 2006