Factors Limiting the Forecast Skill of the Boreal Summer Intraseasonal Oscillation in a Subseasonal-to-Seasonal Model
|
摘要
In this study,we evaluate the forecast skill of the subseasonal-to-seasonal(S2S)prediction model of the Beijing Climate Center(BCC)for the boreal summer intraseasonal oscillation(BSISO).We also discuss the key factors that inhibit the BSISO forecast skill in this model.Based on the bivariate anomaly correlation coefficient(ACC)of the BSISO index,defined by the first two EOF modes of outgoing longwave radiation and 850-hPa zonal wind anomalies over the Asian monsoon region,we found that the hindcast skill degraded as the lead time increased.The ACC dropped to below 0.5for lead times of 11 days and longer when the predicted BSISO showed weakened strength and insignificant northward propagation.To identify what causes the weakened forecast skill of BSISO at the forecast lead time of 11 days,we diagnosed the main mechanisms responsible for the BSISO northward propagation.The same analysis was also carried out using the observations and the outputs of the four-day forecast lead that successfully predicted the observed northward-propagating BSISO.We found that the lack of northward propagation at the 11-day forecast lead was due to insufficient increases in low-level cyclonic vorticity,moistening and warm temperature anomalies to the north of the convection,which were induced by the interaction between background mean flows and BSISO-related anomalous fields.The BCC S2S model can predict the background monsoon circulations,such as the low-level southerly and the northerly and easterly vertical shears,but has limited capability in forecasting the distributions of circulation and moisture anomalies.
In this study,we evaluate the forecast skill of the subseasonal-to-seasonal(S2S)prediction model of the Beijing Climate Center(BCC)for the boreal summer intraseasonal oscillation(BSISO).We also discuss the key factors that inhibit the BSISO forecast skill in this model.Based on the bivariate anomaly correlation coefficient(ACC)of the BSISO index,defined by the first two EOF modes of outgoing longwave radiation and 850-hPa zonal wind anomalies over the Asian monsoon region,we found that the hindcast skill degraded as the lead time increased.The ACC dropped to below 0.5for lead times of 11 days and longer when the predicted BSISO showed weakened strength and insignificant northward propagation.To identify what causes the weakened forecast skill of BSISO at the forecast lead time of 11 days,we diagnosed the main mechanisms responsible for the BSISO northward propagation.The same analysis was also carried out using the observations and the outputs of the four-day forecast lead that successfully predicted the observed northward-propagating BSISO.We found that the lack of northward propagation at the 11-day forecast lead was due to insufficient increases in low-level cyclonic vorticity,moistening and warm temperature anomalies to the north of the convection,which were induced by the interaction between background mean flows and BSISO-related anomalous fields.The BCC S2S model can predict the background monsoon circulations,such as the low-level southerly and the northerly and easterly vertical shears,but has limited capability in forecasting the distributions of circulation and moisture anomalies.
In this study,we evaluate the forecast skill of the subseasonal-to-seasonal(S2S)prediction model of the Beijing Climate Center(BCC)for the boreal summer intraseasonal oscillation(BSISO).We also discuss the key factors that inhibit the BSISO forecast skill in this model.Based on the bivariate anomaly correlation coefficient(ACC)of the BSISO index,defined by the first two EOF modes of outgoing longwave radiation and 850-hPa zonal wind anomalies over the Asian monsoon region,we found that the hindcast skill degraded as the lead time increased.The ACC dropped to below 0.5for lead times of 11 days and longer when the predicted BSISO showed weakened strength and insignificant northward propagation.To identify what causes the weakened forecast skill of BSISO at the forecast lead time of 11 days,we diagnosed the main mechanisms responsible for the BSISO northward propagation.The same analysis was also carried out using the observations and the outputs of the four-day forecast lead that successfully predicted the observed northward-propagating BSISO.We found that the lack of northward propagation at the 11-day forecast lead was due to insufficient increases in low-level cyclonic vorticity,moistening and warm temperature anomalies to the north of the convection,which were induced by the interaction between background mean flows and BSISO-related anomalous fields.The BCC S2S model can predict the background monsoon circulations,such as the low-level southerly and the northerly and easterly vertical shears,but has limited capability in forecasting the distributions of circulation and moisture anomalies.
引文
Annamalai,H.,and J.M.Slingo,2001:Active/break cycles:Diagnosis of the intraseasonal variability of the Asian summer monsoon.Climate Dyn.,18,85-102,https://doi.org/10.1007/s003820100161.
Bellon,G.,and A.H.Sobel,2008:Instability of the axisymmetric monsoon flow and intraseasonal oscillation.J.Geophys.Res.,113,D07108,https://doi.org/10.1029/2007JD009291.
Brunet,G.,and Coauthors,2010:Collaboration of the weather and climate communities to advance subseasonal-to-seasonal prediction.Bull.Amer.Meteor.Soc.,91,1397-1406,https://doi.org/10.1175/2010BAMS3013.1.
Cavanaugh,N.R.,T.Allen,A.Subramanian,B.Mapes,H.Seo,and A.J.Miller,2015:The skill of atmospheric linear inverse models in hindcasting the Madden-Julian Oscillation.Climate Dyn.,44,897-906,https://doi.org/10.1007/s00382-014-2181-x.
Dee,D.P.,and Coauthors,2011:The ERA-Interim reanalysis:Configuration and performance of the data assimilation system.Quart.J.Roy.Meteor.Soc.,137,553-597,https://doi.org/10.1002/qj.828.
DeMott,C.A.,C.Stan,and D.A.Randall,2012:Northward propagation mechanisms of the boreal summer intraseasonal oscillation in the ERA-Interim and SP-CCSM.J.Climate,26,1973-1992,https://doi.org/10.1175/JCLI-D-12-00191.1.
Duchon,C.E.,1979:Lanczos filtering in one and two dimensions.J.Appl.Meteor.,18,1016-1022,https://doi.org/10.1175/1520-0450(1979)018<1016:LFIOAT>2.0.CO;2.
Fu,X.H.,B.Wang,T.Li,and J.Mc Creary,2003:Coupling between northward-propagating intraseasonal oscillations and sea surface temperature in the Indian Ocean.J.Atmos.Sci.,60,1733-1753.https://doi.org/10.1175/1520-0469(2003)060<1733:CBNIOA>2.0.CO;2.
Fu,X.H.,J.Y.Lee,B.Wang,W.Q.Wang,and F.Vitart,2013:Intraseasonal forecasting of the Asian summer monsoon in four operational and research models.J.Climate,26,4186-4203,https://doi.org/10.1175/JCLI-D-12-00252.1.
Griffies,S.M.,and Coauthors,2005:Formulation of an ocean model for global climate simulations.Ocean Science,1,45-79,https://doi.org/10.5194/os-1-45-2005.
Hsu,H.-H.,and C.-H.Weng,2001:Northwestward propagation of the intraseasonal oscillation in the western North Pacific during the boreal summer:Structure and mechanism.J.Climate,14,3834-3850,https://doi.org/10.1175/1520-0442(2001)014<3834:NPOTIO>2.0.CO;2.
Hsu,P.-C.,T.Li,and C.-H.Tsou,2011:Interactions between boreal summer Intraseasonal oscillations and synoptic-scale disturbances over the western North Pacific.Part I:Energetics diagnosis.J.Climate,24,927-941,https://doi.org/10.1175/2010JCLI3833.1.
Hsu,P.-C.,and T.Li,2012:Role of the boundary layer moisture asymmetry in causing the eastward propagation of the Madden-Julian oscillation.J.Climate,25,4914-4931,https://doi.org/10.1175/JCLI-D-11-00310.1.
Hsu,P.-C.,J.-Y.Lee,and K.-J.Ha,2016:Influence of boreal summer intraseasonal oscillation on rainfall extremes in southern China.International Journal of Climatology,36,1403-1412,https://doi.org/10.1002/joc.4433.
Hsu,P.-C.,J.-Y.Lee,K.-J.Ha,and C.-H.Tsou,2017:Influences of boreal summer intraseasonal oscillation on heat waves in monsoon Asia.J.Climate,30,7191-7211,https://doi.org/10.1175/JCLI-D-16-0505.1.
Ji,J.J.,1995:A climate-vegetation interaction model:Simulating physical and biological processes at the surface.Journal of Biogeography,22,445-451,https://doi.org/10.2307/2845941.
Jiang,X.N.,T.Li,and B.Wang,2004:Structures and mechanisms of the northward propagating boreal summer intraseasonal oscillation.J.Climate,17,1022-1039,https://doi.org/10.1175/1520-0442(2004)017<1022:SAMOTN>2.0.CO;2.
Jiang,X.N.,and Coauthors,2015:Vertical structure and physical processes of the Madden-Julian oscillation:Exploring key model physics in climate simulations.J.Geophys.Res.,120,4718-4748,https://doi.org/10.1002/2014JD022375.
Jie,W.H.,F.Vitart,T.W.Wu,and X.W.Liu,2017:Simulations of the Asian Summer Monsoon in the Sub-seasonal to Seasonal Prediction Project(S2S)database.Quart.J.Roy.Meteor.Soc.,143,2282-2295,https://doi.org/10.1002/qj.3085.
Kalnay,E.,and Coauthors,1996:The NCEP/NCAR 40-year reanalysis project.Bull.Amer.Meteor.Soc.,77,437-472,https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2.
Kang,I.S.,and H.M.Kim,2010:Assessment of MJO predictability for boreal winter with various statistical and dynamical models.J.Climate,23,2368-2378,https://doi.org/10.1175/2010JCLI3288.1.
Kemball-Cook,S.,and B.Wang,2001:Equatorial waves and airsea interaction in the boreal summer intraseasonal oscillation.J.Climate,14,2923-2942,https://doi.org/10.1175/1520-0442(2001)014<2923:EWAASI>2.0.CO;2.
Kim,H.M.,P.J.Webster,V.E.Toma,and D.Kim,2014:Predictability and prediction skill of the MJO in two operational forecasting systems.J.Climate,27,5364-5378,https://doi.org/10.1175/JCLI-D-13-00480.1.
Lee,J.Y.,B.Wang,M.C.Wheeler,X.H.Fu,D.E.Waliser,and I.-S.Kang,2013:Real-time multivariate indices for the boreal summer intraseasonal oscillation over the Asian summer monsoon region.Climate Dyn.,40,493-509,https://doi.org/10.1007/s00382-012-1544-4.
Lee,S.S.,B.Wang,D.E.Waliser,J.M.Neena,and J.-Y.Lee,2015:Predictability and prediction skill of the boreal summer intraseasonal oscillation in the Intraseasonal Variability Hindcast Experiment.Climate Dyn.,45,2123-2135,https://doi.org/10.1007/s00382-014-2461-5.
Li,J.Y.,J.Y.Mao,and G.X.Wu,2015:A case study of the impact of boreal summer intraseasonal oscillations on Yangtze rainfall.Climate Dyn.,44,2683-2702,https://doi.org/10.1007/s00382-014-2425-9.
Liebmann,B.,and C.A.Smith,1996:Description of a complete(interpolated)outgoing longwave radiation dataset.Bull.Amer.Meteor.Soc.,77,1275-1277.
Lin,H.,G.Brunet,and J.Derome,2008a:Forecast skill of the Madden-Julian oscillation in two Canadian atmospheric models.Mon.Wea.Rev.,136,4130-4149,https://doi.org/10.1175/2008MWR2459.1.
Lin,J.-L.,M.-I.Lee,D.Kim,I.-S.Kang,and D.M.W.Frierson,2008b:The impacts of convective parameterization and moisture triggering on AGCM-simulated convectively coupled equatorial waves.J.Climate,21,883-909,https://doi.org/10.1175/2007JCLI1790.1.
Liu,X.W.,and Coauthors,2017:MJO prediction using the subseasonal to seasonal forecast model of Beijing Climate Center.Climate Dyn.,48,3283-3307,https://doi.org/10.1007/s00382-016-3264-7.
Madden,R.A.,and P.R.Julian,1971:Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific.J.Atmos.Sci.,28,702-708,https://doi.org/10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2.
Madden,R.A.,and P.R.Julian,1972:Description of globalscale circulation cells in the tropics with a 40-50 day period.J.Atmos.Sci.,29,1109-1123,https://doi.org/10.1175/1520-0469(1972)029<1109:DOGSCC>2.0.CO;2.
Madden R.A.,and P.R.Julian,1994:Observations of the40-50-day tropical oscillation-A review.Mon.Wea.Rev.,122,814-837,https://doi.org/10.1175/1520-0493(1994)122<0814:OOTDTO>2.0.CO;2.
Maloney,E.D.,and M.J.Dickinson,2003:The intraseasonal oscillation and the energetics of summertime tropical western North Pacific synoptic-scale disturbances.J.Atmos.Sci.,60,2153-2168,https://doi.org/10.1175/1520-0469(2003)060<2153:TIOATE>2.0.CO;2.
Mao,J.Y.,and G.X.Wu,2006:Intraseasonal variations of the Yangtze rainfall and its related atmospheric circulation features during the 1991 summer.Climate Dyn.,27,815-830,https://doi.org/10.1007/s00382-006-0164-2.
Rashid,H.A.,H.H.Hendon,M.C.Wheeler,and O.Alves,2011:Prediction of the Madden-Julian oscillation with the POAMAdynamical prediction system.Climate Dyn.,36,649-661,https://doi.org/10.1007/s00382-010-0754-x.
Reynolds,R.W.,T.M.Smith,C.Y.Liu,D.B.Chelton,K.S.Casey,and M.G.Schlax,2007:Daily high-resolutionblended analyses for sea surface temperature.J.Climate,20,5473-5496,https://doi.org/10.1175/2007JCLI1824.1.
Seo,K.H.,W.Q.Wang,J.Gottschalck,Q.Zhang,J.K.E.Schemm,W.R.Higgins,and A.Kumar,2009:Evaluation of MJO forecast skill from several statistical and dynamical forecast models.J.Climate,22,2372-2388,https://doi.org/10.1175/2008JCLI2421.1.
Tsou,C.-H.,P.-C.Hsu,W.-S.Kau,and H.-H.Hsu,2005:Northward and northwestward propagation of 30-60 day oscillation in the tropical and extratropical western North Pacific.J.Meteor.Soc.Japan,83,711-726,https://doi.org/10.2151/jmsj.83.711.
Vitart,F.,C.and Coauthors,2017:The subseasonal to seasonal(S2S)prediction project database.Bull.Amer.Meteor.Soc.,98,163-173,https://doi.org/10.1175/BAMS-D-16-0017.1.
Waliser,D.E.,2006:Predictability of tropical intraseasonal variability.Predictability of Weather and Climate,T.Palmer and R.Hagedorn,Eds.,Cambridge University Press,275-305,https://doi.org/10.1017/CBO9780511617652.012.
Wang,B.,2012:Theory.Intraseasonal Variability in the Atmosphere-Ocean Climate System,W.K.-M.Lau and D.E.Waliser,Eds.,Springer,335-398.
Wang,W.Q.,M.P.Hung,S.J.Weaver,A.Kumar,and X.H.Fu,2014:MJO prediction in the NCEP climate forecast system version 2.Climate Dyn.,42,2509-2520,https://doi.org/10.1007/s00382-013-1806-9.
Webster,P.J.,1983:Mechanisms of monsoon low-frequency variability:Surface hydrological effects.J.Atmos.Sci.,40,2110-2124,https://doi.org/10.1175/1520-0469(1983)040<2110:MOMLFV>2.0.CO;2.
Webster,P.J.,and Coauthors,1998:Monsoon:processes,predictability and the prospects for prediction.J.Geophys.Res.,103,14451-14510,https://doi.org/10.1029/97JC02719.
Wheeler,M.C.,and H.H.Hendon,2004:An all-season real-time multivariate MJO index:Development of an index for monitoring and prediction.Mon.Wea.Rev.,132,1917-1932,https://doi.org/10.1175/1520-0493(2004)132<1917:AARMMI>2.0.CO;2.
Winton,M.,2000:A reformulated three-layer sea ice model.J.Atmos.Oceanic Technol.,17,525-531,https://doi.org/10.1175/1520-0426(2000)017<0525:ARTLSI>2.0.CO;2.
Wu,T.W.,and Coauthors,2010:The Beijing Climate Center atmospheric general circulation model:Description and its performance for the present-day climate.Climate Dyn.,34,123-147,https://doi.org/10.1007/s00382-008-0487-2.
Wu,T.W.,and Coauthors,2014:An overview of BCC climate system model development and application for climate change studies.J.Meteor.Res.,28,34-56,https://doi.org/10.1007/Vs13351-014-3041-7.
Xiang,B.Q.,M.Zhao,X.N.Jiang,S.J.Lin,T.Li,X.H.Fu,and G.Vecchi,2015:The 3-4-week MJO prediction skill in a GFDL coupled model.J.Climate,28,5351-5364,https://doi.org/10.1175/JCLI-D-15-0102.1.
Yasunari,T,1980:A quasi-stationary appearance of 30 to 40 day period in the cloudiness fluctuations during the summer monsoon over India.J.Meteor.Soc.Japan,58,225-229,https://doi.org/10.2151/jmsj1965.58.3 225.
Zhang,C.D.,2005:The madden-Julian oscillation.Rev.Geophys.,43,RG2003,https://doi.org/10.1029/2004RG000158.
Zhu,Z.W.,T.Li,P.-C.Hsu,and J.H.He,2015:A spatialtemporal projection model for extended-range forecast in the tropics.Climate Dyn.,45,1085-1098,https://doi.org/10.1007/s00382-014-2353-8.
Bellon,G.,and A.H.Sobel,2008:Instability of the axisymmetric monsoon flow and intraseasonal oscillation.J.Geophys.Res.,113,D07108,https://doi.org/10.1029/2007JD009291.
Brunet,G.,and Coauthors,2010:Collaboration of the weather and climate communities to advance subseasonal-to-seasonal prediction.Bull.Amer.Meteor.Soc.,91,1397-1406,https://doi.org/10.1175/2010BAMS3013.1.
Cavanaugh,N.R.,T.Allen,A.Subramanian,B.Mapes,H.Seo,and A.J.Miller,2015:The skill of atmospheric linear inverse models in hindcasting the Madden-Julian Oscillation.Climate Dyn.,44,897-906,https://doi.org/10.1007/s00382-014-2181-x.
Dee,D.P.,and Coauthors,2011:The ERA-Interim reanalysis:Configuration and performance of the data assimilation system.Quart.J.Roy.Meteor.Soc.,137,553-597,https://doi.org/10.1002/qj.828.
DeMott,C.A.,C.Stan,and D.A.Randall,2012:Northward propagation mechanisms of the boreal summer intraseasonal oscillation in the ERA-Interim and SP-CCSM.J.Climate,26,1973-1992,https://doi.org/10.1175/JCLI-D-12-00191.1.
Duchon,C.E.,1979:Lanczos filtering in one and two dimensions.J.Appl.Meteor.,18,1016-1022,https://doi.org/10.1175/1520-0450(1979)018<1016:LFIOAT>2.0.CO;2.
Fu,X.H.,B.Wang,T.Li,and J.Mc Creary,2003:Coupling between northward-propagating intraseasonal oscillations and sea surface temperature in the Indian Ocean.J.Atmos.Sci.,60,1733-1753.https://doi.org/10.1175/1520-0469(2003)060<1733:CBNIOA>2.0.CO;2.
Fu,X.H.,J.Y.Lee,B.Wang,W.Q.Wang,and F.Vitart,2013:Intraseasonal forecasting of the Asian summer monsoon in four operational and research models.J.Climate,26,4186-4203,https://doi.org/10.1175/JCLI-D-12-00252.1.
Griffies,S.M.,and Coauthors,2005:Formulation of an ocean model for global climate simulations.Ocean Science,1,45-79,https://doi.org/10.5194/os-1-45-2005.
Hsu,H.-H.,and C.-H.Weng,2001:Northwestward propagation of the intraseasonal oscillation in the western North Pacific during the boreal summer:Structure and mechanism.J.Climate,14,3834-3850,https://doi.org/10.1175/1520-0442(2001)014<3834:NPOTIO>2.0.CO;2.
Hsu,P.-C.,T.Li,and C.-H.Tsou,2011:Interactions between boreal summer Intraseasonal oscillations and synoptic-scale disturbances over the western North Pacific.Part I:Energetics diagnosis.J.Climate,24,927-941,https://doi.org/10.1175/2010JCLI3833.1.
Hsu,P.-C.,and T.Li,2012:Role of the boundary layer moisture asymmetry in causing the eastward propagation of the Madden-Julian oscillation.J.Climate,25,4914-4931,https://doi.org/10.1175/JCLI-D-11-00310.1.
Hsu,P.-C.,J.-Y.Lee,and K.-J.Ha,2016:Influence of boreal summer intraseasonal oscillation on rainfall extremes in southern China.International Journal of Climatology,36,1403-1412,https://doi.org/10.1002/joc.4433.
Hsu,P.-C.,J.-Y.Lee,K.-J.Ha,and C.-H.Tsou,2017:Influences of boreal summer intraseasonal oscillation on heat waves in monsoon Asia.J.Climate,30,7191-7211,https://doi.org/10.1175/JCLI-D-16-0505.1.
Ji,J.J.,1995:A climate-vegetation interaction model:Simulating physical and biological processes at the surface.Journal of Biogeography,22,445-451,https://doi.org/10.2307/2845941.
Jiang,X.N.,T.Li,and B.Wang,2004:Structures and mechanisms of the northward propagating boreal summer intraseasonal oscillation.J.Climate,17,1022-1039,https://doi.org/10.1175/1520-0442(2004)017<1022:SAMOTN>2.0.CO;2.
Jiang,X.N.,and Coauthors,2015:Vertical structure and physical processes of the Madden-Julian oscillation:Exploring key model physics in climate simulations.J.Geophys.Res.,120,4718-4748,https://doi.org/10.1002/2014JD022375.
Jie,W.H.,F.Vitart,T.W.Wu,and X.W.Liu,2017:Simulations of the Asian Summer Monsoon in the Sub-seasonal to Seasonal Prediction Project(S2S)database.Quart.J.Roy.Meteor.Soc.,143,2282-2295,https://doi.org/10.1002/qj.3085.
Kalnay,E.,and Coauthors,1996:The NCEP/NCAR 40-year reanalysis project.Bull.Amer.Meteor.Soc.,77,437-472,https://doi.org/10.1175/1520-0477(1996)077<0437:TNYRP>2.0.CO;2.
Kang,I.S.,and H.M.Kim,2010:Assessment of MJO predictability for boreal winter with various statistical and dynamical models.J.Climate,23,2368-2378,https://doi.org/10.1175/2010JCLI3288.1.
Kemball-Cook,S.,and B.Wang,2001:Equatorial waves and airsea interaction in the boreal summer intraseasonal oscillation.J.Climate,14,2923-2942,https://doi.org/10.1175/1520-0442(2001)014<2923:EWAASI>2.0.CO;2.
Kim,H.M.,P.J.Webster,V.E.Toma,and D.Kim,2014:Predictability and prediction skill of the MJO in two operational forecasting systems.J.Climate,27,5364-5378,https://doi.org/10.1175/JCLI-D-13-00480.1.
Lee,J.Y.,B.Wang,M.C.Wheeler,X.H.Fu,D.E.Waliser,and I.-S.Kang,2013:Real-time multivariate indices for the boreal summer intraseasonal oscillation over the Asian summer monsoon region.Climate Dyn.,40,493-509,https://doi.org/10.1007/s00382-012-1544-4.
Lee,S.S.,B.Wang,D.E.Waliser,J.M.Neena,and J.-Y.Lee,2015:Predictability and prediction skill of the boreal summer intraseasonal oscillation in the Intraseasonal Variability Hindcast Experiment.Climate Dyn.,45,2123-2135,https://doi.org/10.1007/s00382-014-2461-5.
Li,J.Y.,J.Y.Mao,and G.X.Wu,2015:A case study of the impact of boreal summer intraseasonal oscillations on Yangtze rainfall.Climate Dyn.,44,2683-2702,https://doi.org/10.1007/s00382-014-2425-9.
Liebmann,B.,and C.A.Smith,1996:Description of a complete(interpolated)outgoing longwave radiation dataset.Bull.Amer.Meteor.Soc.,77,1275-1277.
Lin,H.,G.Brunet,and J.Derome,2008a:Forecast skill of the Madden-Julian oscillation in two Canadian atmospheric models.Mon.Wea.Rev.,136,4130-4149,https://doi.org/10.1175/2008MWR2459.1.
Lin,J.-L.,M.-I.Lee,D.Kim,I.-S.Kang,and D.M.W.Frierson,2008b:The impacts of convective parameterization and moisture triggering on AGCM-simulated convectively coupled equatorial waves.J.Climate,21,883-909,https://doi.org/10.1175/2007JCLI1790.1.
Liu,X.W.,and Coauthors,2017:MJO prediction using the subseasonal to seasonal forecast model of Beijing Climate Center.Climate Dyn.,48,3283-3307,https://doi.org/10.1007/s00382-016-3264-7.
Madden,R.A.,and P.R.Julian,1971:Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific.J.Atmos.Sci.,28,702-708,https://doi.org/10.1175/1520-0469(1971)028<0702:DOADOI>2.0.CO;2.
Madden,R.A.,and P.R.Julian,1972:Description of globalscale circulation cells in the tropics with a 40-50 day period.J.Atmos.Sci.,29,1109-1123,https://doi.org/10.1175/1520-0469(1972)029<1109:DOGSCC>2.0.CO;2.
Madden R.A.,and P.R.Julian,1994:Observations of the40-50-day tropical oscillation-A review.Mon.Wea.Rev.,122,814-837,https://doi.org/10.1175/1520-0493(1994)122<0814:OOTDTO>2.0.CO;2.
Maloney,E.D.,and M.J.Dickinson,2003:The intraseasonal oscillation and the energetics of summertime tropical western North Pacific synoptic-scale disturbances.J.Atmos.Sci.,60,2153-2168,https://doi.org/10.1175/1520-0469(2003)060<2153:TIOATE>2.0.CO;2.
Mao,J.Y.,and G.X.Wu,2006:Intraseasonal variations of the Yangtze rainfall and its related atmospheric circulation features during the 1991 summer.Climate Dyn.,27,815-830,https://doi.org/10.1007/s00382-006-0164-2.
Rashid,H.A.,H.H.Hendon,M.C.Wheeler,and O.Alves,2011:Prediction of the Madden-Julian oscillation with the POAMAdynamical prediction system.Climate Dyn.,36,649-661,https://doi.org/10.1007/s00382-010-0754-x.
Reynolds,R.W.,T.M.Smith,C.Y.Liu,D.B.Chelton,K.S.Casey,and M.G.Schlax,2007:Daily high-resolutionblended analyses for sea surface temperature.J.Climate,20,5473-5496,https://doi.org/10.1175/2007JCLI1824.1.
Seo,K.H.,W.Q.Wang,J.Gottschalck,Q.Zhang,J.K.E.Schemm,W.R.Higgins,and A.Kumar,2009:Evaluation of MJO forecast skill from several statistical and dynamical forecast models.J.Climate,22,2372-2388,https://doi.org/10.1175/2008JCLI2421.1.
Tsou,C.-H.,P.-C.Hsu,W.-S.Kau,and H.-H.Hsu,2005:Northward and northwestward propagation of 30-60 day oscillation in the tropical and extratropical western North Pacific.J.Meteor.Soc.Japan,83,711-726,https://doi.org/10.2151/jmsj.83.711.
Vitart,F.,C.and Coauthors,2017:The subseasonal to seasonal(S2S)prediction project database.Bull.Amer.Meteor.Soc.,98,163-173,https://doi.org/10.1175/BAMS-D-16-0017.1.
Waliser,D.E.,2006:Predictability of tropical intraseasonal variability.Predictability of Weather and Climate,T.Palmer and R.Hagedorn,Eds.,Cambridge University Press,275-305,https://doi.org/10.1017/CBO9780511617652.012.
Wang,B.,2012:Theory.Intraseasonal Variability in the Atmosphere-Ocean Climate System,W.K.-M.Lau and D.E.Waliser,Eds.,Springer,335-398.
Wang,W.Q.,M.P.Hung,S.J.Weaver,A.Kumar,and X.H.Fu,2014:MJO prediction in the NCEP climate forecast system version 2.Climate Dyn.,42,2509-2520,https://doi.org/10.1007/s00382-013-1806-9.
Webster,P.J.,1983:Mechanisms of monsoon low-frequency variability:Surface hydrological effects.J.Atmos.Sci.,40,2110-2124,https://doi.org/10.1175/1520-0469(1983)040<2110:MOMLFV>2.0.CO;2.
Webster,P.J.,and Coauthors,1998:Monsoon:processes,predictability and the prospects for prediction.J.Geophys.Res.,103,14451-14510,https://doi.org/10.1029/97JC02719.
Wheeler,M.C.,and H.H.Hendon,2004:An all-season real-time multivariate MJO index:Development of an index for monitoring and prediction.Mon.Wea.Rev.,132,1917-1932,https://doi.org/10.1175/1520-0493(2004)132<1917:AARMMI>2.0.CO;2.
Winton,M.,2000:A reformulated three-layer sea ice model.J.Atmos.Oceanic Technol.,17,525-531,https://doi.org/10.1175/1520-0426(2000)017<0525:ARTLSI>2.0.CO;2.
Wu,T.W.,and Coauthors,2010:The Beijing Climate Center atmospheric general circulation model:Description and its performance for the present-day climate.Climate Dyn.,34,123-147,https://doi.org/10.1007/s00382-008-0487-2.
Wu,T.W.,and Coauthors,2014:An overview of BCC climate system model development and application for climate change studies.J.Meteor.Res.,28,34-56,https://doi.org/10.1007/Vs13351-014-3041-7.
Xiang,B.Q.,M.Zhao,X.N.Jiang,S.J.Lin,T.Li,X.H.Fu,and G.Vecchi,2015:The 3-4-week MJO prediction skill in a GFDL coupled model.J.Climate,28,5351-5364,https://doi.org/10.1175/JCLI-D-15-0102.1.
Yasunari,T,1980:A quasi-stationary appearance of 30 to 40 day period in the cloudiness fluctuations during the summer monsoon over India.J.Meteor.Soc.Japan,58,225-229,https://doi.org/10.2151/jmsj1965.58.3 225.
Zhang,C.D.,2005:The madden-Julian oscillation.Rev.Geophys.,43,RG2003,https://doi.org/10.1029/2004RG000158.
Zhu,Z.W.,T.Li,P.-C.Hsu,and J.H.He,2015:A spatialtemporal projection model for extended-range forecast in the tropics.Climate Dyn.,45,1085-1098,https://doi.org/10.1007/s00382-014-2353-8.