Energetic processes regulating the strength of MJO circulation over the Maritime Continent during two types of El Ni?o
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摘要
不同类型的El Ni?o事件对海洋性大陆区域的MJO强度有显著的影响。其中,中太平洋型(CP)El Ni?o期间的秋冬季MJO环流在海洋性大陆区域变得更强。本文推导了新的MJO动能诊断方程,并以此来定量诊断两类El Ni?o期间调控海洋性大陆区域的MJO环流强度的物理过程。与EP El Ni?o相比,CP El Ni?o期间平均动能与MJO动能之间的正压能量转换增强。在CP El Ni?o期间,沃克环流在海洋性大陆区域出现上升异常、低层辐合和气旋异常,透过正压能量转换,MJO得以从平均气流场中获得较多的动能;并进一步透过斜压能量转换,来维持MJO自身的强度增长。CP El Ni?o期间,增强的MJO将其动能转给高频扰动,有利海洋性大陆区域的高频扰动发展。
The zonal shift of SST warming patterns associated with the eastern Pacific(EP) and central Pacific(CP) El Ni?o leads to a significant contrast in MJO strength over the Maritime Continent. The MJO circulation tends to be stronger over the Maritime Continent during the mature phase(autumnwinter) of CP El Ni?o than of EP El Ni?o. Based on a new MJO kinetic energy(KE) budget equation, in which the effects of mean flow and high-frequency disturbances on the MJO are separated, we found that the low-level MJO gains more KE from the background mean flow during CP El Ni?o events, although at the same time the enhanced MJO transfers more KE to high-frequency eddies. Among the three-dimensional circulation anomalies, the low-level convergence and cyclonic anomalies associated with upward anomalies of the Walker circulation over the Maritime Continent play leading roles in inducing the enhanced barotropic energy conversion from mean flow to MJO during CP El Ni?o events relative to EP El Ni?o events. The more vigorous MJO with strengthened vertical motion and heating anomalies at the upper troposphere can maintain its amplitude through the baroclinic energy conversion from the MJO available potential energy to KE. Both the low-tomid tropospheric barotropic energy conversion from mean flow to MJO and upper-level baroclinic energy conversion contribute positively to the enhanced MJO over the Maritime Continent during CP El Ni?o years compared to during EP El Ni?o years.
The zonal shift of SST warming patterns associated with the eastern Pacific(EP) and central Pacific(CP) El Ni?o leads to a significant contrast in MJO strength over the Maritime Continent. The MJO circulation tends to be stronger over the Maritime Continent during the mature phase(autumnwinter) of CP El Ni?o than of EP El Ni?o. Based on a new MJO kinetic energy(KE) budget equation, in which the effects of mean flow and high-frequency disturbances on the MJO are separated, we found that the low-level MJO gains more KE from the background mean flow during CP El Ni?o events, although at the same time the enhanced MJO transfers more KE to high-frequency eddies. Among the three-dimensional circulation anomalies, the low-level convergence and cyclonic anomalies associated with upward anomalies of the Walker circulation over the Maritime Continent play leading roles in inducing the enhanced barotropic energy conversion from mean flow to MJO during CP El Ni?o events relative to EP El Ni?o events. The more vigorous MJO with strengthened vertical motion and heating anomalies at the upper troposphere can maintain its amplitude through the baroclinic energy conversion from the MJO available potential energy to KE. Both the low-tomid tropospheric barotropic energy conversion from mean flow to MJO and upper-level baroclinic energy conversion contribute positively to the enhanced MJO over the Maritime Continent during CP El Ni?o years compared to during EP El Ni?o years.
引文
Camargo,S.J.,M.C.Wheeler,and A.H.Sobel.2009.“Diagnosis of the MJO modulation of tropical cyclogenesis using an empirical index.”Journal of the Atmospheric Sciences 66(10):3061-3074.
Chang,C.-P.,P.A.Harr,and H.J.Chen.2005.“Synoptic disturbances over the equatorial South China Sea and western Maritime Continent during boreal winter.”Monthly Weather Review 133(3):489-503.
Chen,X.,J.Ling,and C.Y.Li.2016.“Evolution of the MaddenJulian oscillation in two types of El Ni?o.”Journal of Climate29(5):1919-1934.
Dee,D.P.,S.M.Uppala,A.J.Simmons,P.Berrisford,P.Poli,S.Kobayashi,U.Andrae,et al.2011.“The ERA-Interim reanalysis:configuration and performance of the data assimilation system.”Quarterly Journal of the Royal Meteorological Society137(656):553-597.
Duchon,C.E.1979.“Lanczos filtering in one and two dimensions.”Journal of Applied Meteorology 18(8):1016-1022.
Feng,J.,P.Liu,W.Chen,and X.C.Wang.2015.“Contrasting Madden-Julian Oscillation activity during various stages of EP and CP El Ni?os.”Atmospheric Science Letters 16(1):32-37.
Gushchina,D.,and B.Dewitte.2012.“Intraseasonal tropical atmospheric variability associated with the two flavors of El Ni?o.”Monthly Weather Review 140(11):3669-3681.
Hendon,H.H.,C.Zhang,and J.D.Glick.1999.“Interannual variation of the Madden-Julian oscillation during austral summer.”Journal of Climate 12(8):2538-2550.
Hendon,H.H.,M.C.Wheeler,and C.Zhang.2007.“Seasonal dependence of the MJO-ENSO relationship.”Journal of Climate 20:531-543.
Hsu,P.-C.,and C.-H.Tsou,2009.“Eddy energy along the tropical storm track in association with ENSO.”Journal of the Meteorological Society of Japan Ser.II 87(4):687-704.
Hsu,P.-C.,and T.Xiao.2017.“Differences in the initiation and development of the Madden-Julian Oscillation over the Indian Ocean associated with two types of El Ni?o.”Journal of Climate 30(4):1397-1415.
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*.”Journal of Climate 24(3):927-941.
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(3):1403-1412.
Kessler,W.S.2001.“EOF representations of the Madden-Julian oscillation and its connection with ENSO.”Journal of Climate14(13):3055-3061.
Lau,K.-H.,and N.-C.Lau.1992.“The energetics and propagation dynamics of tropical summertime synoptic-scale disturbances.”Monthly Weather Review 120(11):2523-2539.
Lee,J.-Y.,B.Wang,M.C.Wheeler,X.H.Fu,E.Duane,and W.-S.Kang.2013.“Real-time multivariate indices for the boreal summer intraseasonal oscillation over the Asian summer monsoon region.”Climate Dynamics 40(1-2):493-509.
Liebmann,B.,and C.A.Smith 1996.“Description of a complete(interpolated)outgoing longwave radiation dataset.”Bulletin of the American Meteorological Society 77:1275-1277.
Madden,R.A.,and P.R.Julian.1971.“Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific.”Journal of the Atmospheric Sciences 28(5):702-708.
Maloney,E.D.,and M.J.Dickinson.2003.“The intraseasonal oscillation and the energetics of summertime tropical western North Pacific synoptic-scale disturbances.”Journal of the Atmospheric Sciences 60(17):2153-2168.
Mao,J.Y.,Z.Sun,and G.X.Wu.2010.“20-50-day oscillation of summer Yangtze rainfall in response to intraseasonal variations in the subtropical high over the western North Pacific and South China Sea.”Climate Dynamics 34(5):747-761.
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Oort,A.H.1964.“On estimates of the atmospheric energy cycle.”Monthly Weather Review 92(11):483-493.
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Rayner,N.A.,D.E.Parker,E.B.Horton,C.K.Folland,L.V.Alexander,P.Rowell,C.Kent,and A.Kaplan.2003.“Global analyses of sea surface temperature,sea ice,and night marine air temperature since the late nineteenth century.”Journal of Geophysical Research:Atmospheres 108(D14):4407.doi:10.1029/2002JD002670.
Ren,H.-L.,and F.-F.Jin.2011.“Ni?o indices for two types of ENSO.”Geophysical Research Letters 38(4):L04704.
Slingo,J.M.,D.P.Rowe,R.Sperber,and F.Nortley.1999.“On the predictability of the interannual behaviour of the MaddenJulian Oscillation and its relationship with El Ni?o.”Quarterly Journal of the Royal Meteorological Society 125(554):583-609.
Smith,T.M.,R.W.Reynolds,T.C.Peterson,and J.Lawrimore.2008.“Improvements to NOAA’s Historical Merged Landocean Surface Temperature Analysis(1880-2006).”Journal of Climate 21:2283-2296.
Tsou,C.-H.,H.-H.Hsu,and P.-C.Hsu.2014.“The role of multiscale interaction in synoptic-scale eddy kinetic energy over the western North Pacific in autumn.”Journal of Climate 27(10):3750-3766.
Waliser,D.E.2006.“Intraseasonal variability.”The Asian Monsoon.Springer Berlin Heidelberg,203-257.
Wang,B.,R.Wu,and X.Fu.2000.“Pacific-East Asian teleconnection:How does ENSO affect East Asian climate?”Journal of Climate 13(9):1517-1536.
Yang,J.2010.“Biweekly and 21-30-day variations of the subtropical summer monsoon rainfall over the lower reach of the Yangtze River basin.”Journal of Climate 23(5):1146-1159.
Yeh,S.-W.,J.-S.Kug,B.Dewitte,M.-H.Kwon,B.P.Kirtman,and F.-F.Jin.2009.“El Ni?o in a changing climate.”Nature 461(7263):511-514.
Yuan,Y.,S.Yang,and Z.Zhang.2012.“Different evolutions of the Philippine Sea anticyclone between the eastern and central Pacific El Ni?o:Possible effects of Indian Ocean SST.”Journal of Climate 25(22):7867-7883.
Yuan,Y.,C.Y.Li,and J.Ling.2015.“Different MJO activities between EP El Ni?o and CP El Ni?o.”Scientia Sinica Terrae 45:318-334.
Chang,C.-P.,P.A.Harr,and H.J.Chen.2005.“Synoptic disturbances over the equatorial South China Sea and western Maritime Continent during boreal winter.”Monthly Weather Review 133(3):489-503.
Chen,X.,J.Ling,and C.Y.Li.2016.“Evolution of the MaddenJulian oscillation in two types of El Ni?o.”Journal of Climate29(5):1919-1934.
Dee,D.P.,S.M.Uppala,A.J.Simmons,P.Berrisford,P.Poli,S.Kobayashi,U.Andrae,et al.2011.“The ERA-Interim reanalysis:configuration and performance of the data assimilation system.”Quarterly Journal of the Royal Meteorological Society137(656):553-597.
Duchon,C.E.1979.“Lanczos filtering in one and two dimensions.”Journal of Applied Meteorology 18(8):1016-1022.
Feng,J.,P.Liu,W.Chen,and X.C.Wang.2015.“Contrasting Madden-Julian Oscillation activity during various stages of EP and CP El Ni?os.”Atmospheric Science Letters 16(1):32-37.
Gushchina,D.,and B.Dewitte.2012.“Intraseasonal tropical atmospheric variability associated with the two flavors of El Ni?o.”Monthly Weather Review 140(11):3669-3681.
Hendon,H.H.,C.Zhang,and J.D.Glick.1999.“Interannual variation of the Madden-Julian oscillation during austral summer.”Journal of Climate 12(8):2538-2550.
Hendon,H.H.,M.C.Wheeler,and C.Zhang.2007.“Seasonal dependence of the MJO-ENSO relationship.”Journal of Climate 20:531-543.
Hsu,P.-C.,and C.-H.Tsou,2009.“Eddy energy along the tropical storm track in association with ENSO.”Journal of the Meteorological Society of Japan Ser.II 87(4):687-704.
Hsu,P.-C.,and T.Xiao.2017.“Differences in the initiation and development of the Madden-Julian Oscillation over the Indian Ocean associated with two types of El Ni?o.”Journal of Climate 30(4):1397-1415.
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*.”Journal of Climate 24(3):927-941.
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(3):1403-1412.
Kessler,W.S.2001.“EOF representations of the Madden-Julian oscillation and its connection with ENSO.”Journal of Climate14(13):3055-3061.
Lau,K.-H.,and N.-C.Lau.1992.“The energetics and propagation dynamics of tropical summertime synoptic-scale disturbances.”Monthly Weather Review 120(11):2523-2539.
Lee,J.-Y.,B.Wang,M.C.Wheeler,X.H.Fu,E.Duane,and W.-S.Kang.2013.“Real-time multivariate indices for the boreal summer intraseasonal oscillation over the Asian summer monsoon region.”Climate Dynamics 40(1-2):493-509.
Liebmann,B.,and C.A.Smith 1996.“Description of a complete(interpolated)outgoing longwave radiation dataset.”Bulletin of the American Meteorological Society 77:1275-1277.
Madden,R.A.,and P.R.Julian.1971.“Detection of a 40-50 day oscillation in the zonal wind in the tropical Pacific.”Journal of the Atmospheric Sciences 28(5):702-708.
Maloney,E.D.,and M.J.Dickinson.2003.“The intraseasonal oscillation and the energetics of summertime tropical western North Pacific synoptic-scale disturbances.”Journal of the Atmospheric Sciences 60(17):2153-2168.
Mao,J.Y.,Z.Sun,and G.X.Wu.2010.“20-50-day oscillation of summer Yangtze rainfall in response to intraseasonal variations in the subtropical high over the western North Pacific and South China Sea.”Climate Dynamics 34(5):747-761.
Mc Phaden,M.J.,T.Lee,and D.Mc Clurg.2011.“El Ni?o and its relationship to changing background conditions in the tropical Pacific Ocean.”Geophysical Research Letters 38(15):L15790.
Oort,A.H.1964.“On estimates of the atmospheric energy cycle.”Monthly Weather Review 92(11):483-493.
Palmer,T.N.,F.J.Doblas-Reyes,A.Weisheimer,and M.J.Rodwell.2008.“Toward seamless prediction:Calibration of climate change projections using seasonal forecasts.”Bulletin of the American Meteorological Society 89(4):459-470.
Rayner,N.A.,D.E.Parker,E.B.Horton,C.K.Folland,L.V.Alexander,P.Rowell,C.Kent,and A.Kaplan.2003.“Global analyses of sea surface temperature,sea ice,and night marine air temperature since the late nineteenth century.”Journal of Geophysical Research:Atmospheres 108(D14):4407.doi:10.1029/2002JD002670.
Ren,H.-L.,and F.-F.Jin.2011.“Ni?o indices for two types of ENSO.”Geophysical Research Letters 38(4):L04704.
Slingo,J.M.,D.P.Rowe,R.Sperber,and F.Nortley.1999.“On the predictability of the interannual behaviour of the MaddenJulian Oscillation and its relationship with El Ni?o.”Quarterly Journal of the Royal Meteorological Society 125(554):583-609.
Smith,T.M.,R.W.Reynolds,T.C.Peterson,and J.Lawrimore.2008.“Improvements to NOAA’s Historical Merged Landocean Surface Temperature Analysis(1880-2006).”Journal of Climate 21:2283-2296.
Tsou,C.-H.,H.-H.Hsu,and P.-C.Hsu.2014.“The role of multiscale interaction in synoptic-scale eddy kinetic energy over the western North Pacific in autumn.”Journal of Climate 27(10):3750-3766.
Waliser,D.E.2006.“Intraseasonal variability.”The Asian Monsoon.Springer Berlin Heidelberg,203-257.
Wang,B.,R.Wu,and X.Fu.2000.“Pacific-East Asian teleconnection:How does ENSO affect East Asian climate?”Journal of Climate 13(9):1517-1536.
Yang,J.2010.“Biweekly and 21-30-day variations of the subtropical summer monsoon rainfall over the lower reach of the Yangtze River basin.”Journal of Climate 23(5):1146-1159.
Yeh,S.-W.,J.-S.Kug,B.Dewitte,M.-H.Kwon,B.P.Kirtman,and F.-F.Jin.2009.“El Ni?o in a changing climate.”Nature 461(7263):511-514.
Yuan,Y.,S.Yang,and Z.Zhang.2012.“Different evolutions of the Philippine Sea anticyclone between the eastern and central Pacific El Ni?o:Possible effects of Indian Ocean SST.”Journal of Climate 25(22):7867-7883.
Yuan,Y.,C.Y.Li,and J.Ling.2015.“Different MJO activities between EP El Ni?o and CP El Ni?o.”Scientia Sinica Terrae 45:318-334.