Sixteenth Session of the Forum on Regional Climate Monitoring, Assessment and Prediction for Asia (FOCRAII), May 7, 2020 ( ), y , Outlook of Summer Rainfall Anomaly in Asia with Outlook of Summer Rainfall Anomaly in Asia with SMART-based Seasonal Prediction System (SMART-SPS) Xiu-Qun Yang xqyang@nju.edu.cn CMA-NJU Joint Laboratory for Climate Prediction Studies ( LCPS/CMA-NJU ) S h School of Atmospheric Sciences, Nanjing University, Nanjing, China l f At h i S i N ji U i it N ji Chi
Brief introduction to SMART-SPS SMART-based Seasonal Prediction System ( S VD M ode and A nomalous R ainfall T endency based S easonal P rediction S ystem ) ( S VD M ode and A nomalous R ainfall T endency-based S easonal P rediction S ystem ) Predict the rainfall anomaly by predicting its interannual tendency ( ( Fan et al., 2007 ) ) Let interannual tendency : R t ( 1) R t ( 1) R t ( ) then: R t ( 1) R t ( ) R t ( 1) R ( t 1) R ( ) t R ( t 1) fcst obs fcst Rainfall Anom Rainfall Anom Difference between this summer last summer two summers
Brief introduction to SMART-SPS SMART-based Seasonal Prediction System ( S VD M ode and A nomalous R ainfall T endency based S easonal P rediction S ystem ) ( S VD M ode and A nomalous R ainfall T endency-based S easonal P rediction S ystem ) Two strategies to predict the Anomalous Rainfall Tendency (ART) ( Yang, Sun, Wang, et al., 2011; 2019 ) ( Yang Sun Wang et al 2011; 2019 ) SMART-based P hysical- S tatistical M odel ( SMART-PSM ) - Determine preceding (say, JFM) atmospheric S VD M odes with JJA ART D i di ( JFM) h i S VD M d i h JJA ART - Build MRM for JJA ART using those preceding S VD M odes - Predict JJA ART with the MRM using observed preceding S VD M odes SMART-based D ynamical- S tatistical combined M odel ( SMART-DSM ) - Determine simultaneous atmospheric S VD M odes with JJA ART - Determine simultaneous atmospheric S VD M odes with JJA ART - Predict those S VD modes with BCC-CSM1.1m’s ensemble predictions - Reconstruct ART with MRM in terms of those predicted S VD M odes
Prediction of JJA Rainfall Anomaly Percentage (RAP) with SMART-PSM ACC ： tendency ACC ： anomaly or OLR Independent validation for SVD mode selection for SVD mode selection modes fo from recent 5 years 6 6 f SVD m 6 6 Nolr=6 PS ： anomaly RMSD ： anomaly Nz500=6 mber of Num 6 6 GPCP data 6 6 Number of SVD modes for Z500 2020/5/7 4
Prediction of JJA Rainfall Anomaly Percentage (RAP) with SMART-PSM Observed JJA RAP in 2019 ( 1) ( ) ( 1) R t R t R t fcst obs fcst Predicted JJA RAP in 2020 Predicted JJA ART percentage in 2020 with preceding JFM SVD Modes 5 2020/5/7
Reasons for the prediction – tropical signals JFM SSTA in 2019 JFM SSTA in 2920 Interannual Tendency of SSTA • Similar SSTA distribution except TIO where there is a slight warming h h l h • Without significant ENSO signature 2019 2020
Reasons for the prediction – tropical signals 2019 JFM OLR Anomaly 2020 JFM OLR Anomaly Enhanced 2020 minus 2019 JFM OLR Tendency convection in western IO western IO
Reasons for the prediction – tropical signals SVD mode 6: interannual tendency of JFM OLR & JJA Rainfall SVD mode-6: interannual tendency of JFM OLR & JJA Rainfall Predicted 2020 JJA rainfall tendency Observed 2020 JFM OLR tendency
Reasons for the prediction – extratropical signals 2019 2020 2020 minus 2019 2020 minus 2019 JFM Z500 JFM Z500 JFM Z500 Tendency Anomaly Anomaly Shifted AO- like pattern
Reasons for the prediction – extratropical signals SVD mode 2: interannual tendency of JFM Z500 & JJA Rainfall SVD mode-2: interannual tendency of JFM Z500 & JJA Rainfall Predicted 2020 JJA rainfall tendency Observed 2020 JFM Z500 tendency
Reasons for the prediction – extratropical signals SVD mode 6: interannual tendency of JFM Z500 & JJA Rainfall SVD mode-6: interannual tendency of JFM Z500 & JJA Rainfall Predicted 2020 JJA rainfall tendency Observed 2020 JFM Z500 tendency
Reasons for the prediction – decadal background PDO index （ from JMA ） （ ） Positive PDO p phase Annual mean 5-yr running mean 2014->2020 AMO index （ Enfield et al. 2001 ） P Positive iti AMO phase Zhang, Sun, Yang (2018)@JC 2020/5/7
Reasons for the prediction – decadal background Recent 5-yr （ 2015-2019 ） averaged JJA Recent 5-yr （ 2015-2019 ） averaged JJA Predicted JJA ART Predicted JJA ART rainfall anomaly Predicted JJA total rainfall anomaly Interannual anomaly Decadal background Combined impact of interannual and interannual and decadal anomalies 2020/5/7
Associated predictions of JJA atmospheric circulation anomalies with SMART-PSM Observed: 2019 JJA JJ Predicted: 2020 JJA JJ Predicted: 2020 JJA JJ anomaly tendency anomaly A A A A C C A C C A A A A A A A A A 2020/5/7
Prediction of JJA Rainfall Anomaly Percentage (RAP) with SMART-DSM Observed summer RAP in 2019 Predicted summer ART percentage in 2020 (GPCP data) with preceding JFM signatures + Predicted summer RAP in 2020 2020/5/7
Predictions of JJA Rainfall Anomaly Percentage (RAP) SMART-PSM versus SMART-DSM Predicted summer RAP in 2020 Predicted summer RAP in 2020 C Contact: Dr. Xiu-Qun Yang, xqyang@nju.edu.cn t t D Xi Q Y @ j d http://lcps.nju.edu.cn
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