The atmospheric anomalies associated with the drought over the Yangtze River basin during spring 2011

The middle and lower reaches of the Yangtze River basin (MLRY) suffered a once-in-a-50-year drought during the spring of 2011. The abnormality of the atmospheric circulation in the spring is characterized by the deeper-than-normal trough over East Asia and the northwest Pacific while stronger-than-normal high-pressure system over the west, which results in a stronger-than-normal meridional circulation. Meanwhile, the western Pacific subtropical high is weaker than normal and retreats to the east, so the spring monsoonal moist air from lower latitudes is relatively weak. The anomalous northerly wind in higher latitudes suppresses the northward motion of the moist air and brings dry air to the MLRY. The northerly wind also suppresses the northward motion of warm air and brings cold air to the MLRY. So finally, the air over the MLRY is drier, but colder than normal, which is different from many other droughts. The coldness of the air plays a negative role to the drought. Results from comparing the Cq and CT, the measures of the changes in moisture and temperature between this spring and the normal spring defined based on the tight precipitation-relative humidity relation, indicate that the dryness of the air is much stronger than the coldness, and the air over the MLRY thus maintains a lower-than-normal relative humidity. The animation of daily Cq and CT shows that dry and cold air moves from the northwest to the MLRY in a manner of low-frequency oscillation.

[1]  W. Qian,et al.  Ranking regional drought events in China for 1960–2009 , 2011 .

[2]  Richard R. Heim,et al.  Recent Variations of Snow Cover and Snowfall in North America and Their Relation to Precipitation and Temperature Variations , 1993 .

[3]  Liu Yimin,et al.  Summer monsoon rainfalls over Mid—Eastern China lagged correlated with global SSTs , 2001 .

[4]  R. Lu,et al.  Spring Indian Ocean-western Pacific SST contrast and the East Asian summer rainfall anomaly , 2013, Advances in Atmospheric Sciences.

[5]  M. Hoerling,et al.  Central U.S. Springtime Precipitation Extremes: Teleconnections and Relationships with Sea Surface Temperature , 2001 .

[6]  J. Wallace,et al.  The Arctic oscillation signature in the wintertime geopotential height and temperature fields , 1998 .

[7]  Chang‐Hoi Ho,et al.  Changes in occurrence of cold surges over east Asia in association with Arctic Oscillation , 2005 .

[8]  Thomas M. Smith,et al.  Improvements to NOAA’s Historical Merged Land–Ocean Surface Temperature Analysis (1880–2006) , 2008 .

[9]  C. Deser,et al.  Why the Western Pacific Subtropical High Has Extended Westward since the Late 1970s , 2009 .

[10]  Shuqing Sun,et al.  Anomalous midsummer rainfall in Yangtze River-Huaihe River valleys and its association with the East Asia westerly jet , 2011 .

[11]  Yang Hui,et al.  The characteristics of longitudinal movement of the subtropical high in the western Pacific in the pre-rainy season in South China , 2005 .

[12]  T. McKee,et al.  THE RELATIONSHIP OF DROUGHT FREQUENCY AND DURATION TO TIME SCALES , 1993 .

[13]  Zhang Shengjun,et al.  Characteristics of the correlation between regional water vapor transport along with the convective action and variation of the Pacific subtropical high in 1998 , 2003 .

[14]  Qiang Zhang,et al.  The day-to-day monitoring of the 2011 severe drought in China , 2014, Climate Dynamics.

[15]  Hao Ma,et al.  Coupled modes of rainfall over China and the pacific sea surface temperature in boreal summertime , 2011 .

[16]  T. Zhou,et al.  Seasonality and Three-Dimensional Structure of Interdecadal Change in the East Asian Monsoon , 2007 .

[17]  L. Jianping,et al.  Interannual Variability of Autumn Precipitation over South China and its Relation to Atmospheric Circulation and SST Anomalies , 2008 .

[18]  Tim Li,et al.  Relative Contributions of the Indian Ocean and Local SST Anomalies to the Maintenance of the Western North Pacific Anomalous Anticyclone during the El Niño Decaying Summer , 2010 .

[19]  M. Clark,et al.  Relationships between Spring Snow Mass and Summer Precipitation in the Southwestern United States Associated with the North American Monsoon System , 2002 .

[20]  Yali Luo,et al.  Regional atmospheric anomalies responsible for the 2009–2010 severe drought in China , 2011 .

[21]  Wang Jizhi,et al.  The water vapor transport model at the regional boundary during the Meiyu period , 2003 .

[22]  G. North,et al.  Climatic Influence of Sea Surface Temperature: Evidence of Substantial Precipitation Correlation and Predictability , 2003 .

[23]  T. McKee,et al.  Drought monitoring with multiple time scales , 1995 .

[24]  Richard R. Heim,et al.  Are droughts becoming more frequent or severe in China based on the Standardized Precipitation Evapotranspiration Index: 1951–2010? , 2011 .

[25]  Guo Yufu,et al.  Numerical simulation of the relationships between the 1998 yangtze river valley floods and SST anomalies , 2002 .

[26]  A theoretical analysis on the local climate change induced by the change of landuse , 2002 .

[27]  Akimasa Sumi,et al.  A diagnostic study of the impact of El Niño on the precipitation in China , 1999 .

[28]  Z. Renhe.  Relations of Water Vapor Transport from Indian Monsoon with That over East Asia and the Summer Rainfall in China , 2001 .

[29]  Chengming Wen.  Linkage Between the Arctic Oscillation and Winter Climate over East Asia on the Interannual Timescale: Roles of Quasi-Stationary Planetary Waves , 2006 .

[30]  E. Lu,et al.  Determining the start, duration, and strength of flood and drought with daily precipitation: Rationale , 2009 .

[31]  Thomas M. Smith,et al.  Interdecadal Changes of 30-Yr SST Normals during 1871–2000 , 2003 .

[32]  W. Higgins,et al.  Impacts of land process on the onset and evolution of Asian summer monsoon in the NCEP climate forecast system , 2011 .

[33]  Bin Wang,et al.  Tropospheric cooling and summer monsoon weakening trend over East Asia , 2004 .

[34]  W. Dong,et al.  The influence of vegetation cover on summer precipitation in China: A statistical analysis of NDVI and climate data , 2003 .

[35]  J. Chan,et al.  Influence of South China Sea SST and the ENSO on winter rainfall over South China , 2010 .

[36]  Tianjun Zhou,et al.  Atmospheric water vapor transport associated with typical anomalous summer rainfall patterns in China , 2005 .

[37]  K. Lau,et al.  Upstream Subtropical Signals Preceding the Asian Summer Monsoon Circulation , 2004 .

[38]  Rong-hui Huang,et al.  The influence of ENSO on the summer climate change in China and its mechanism , 1989 .

[39]  M. Kanamitsu,et al.  NCEP–DOE AMIP-II Reanalysis (R-2) , 2002 .

[40]  Thomas C. Peterson,et al.  Editorial and Production Team , 2023, The Toro Historical Review.

[41]  Kun Yang,et al.  Eurasian snow cover variability and its association with summer rainfall in China , 2009 .

[42]  D. Zheng,et al.  Depiction of the Variations of Great Plains Precipitation and Its Relationship with Tropical Central-Eastern Pacific SST , 2007 .

[43]  D. Gong,et al.  East Asian Winter Monsoon and Arctic Oscillation , 2001 .

[44]  Xue Feng,et al.  The spring monsoon in south china and its relationship to Large—Scale circulation features , 2002 .

[45]  Y. Shao,et al.  Revisiting the climatology of atmospheric blocking in the Northern Hemisphere , 2013, Advances in Atmospheric Sciences.

[46]  Li Shuanglin,et al.  The maintenance of the blocking over the ural mountains during the second Meiyu period in the summer of 1998 , 2001 .

[47]  A. Dai,et al.  Responses of East Asian summer monsoon to historical SST and atmospheric forcing during 1950–2000 , 2010 .

[48]  Z. Bao,et al.  Eurasian snow conditions and summer monsoon rainfall over South and Southeast Asia: Assessment and comparison , 2005 .

[49]  Bradfield Lyon,et al.  ENSO and the Spatial Extent of Interannual Precipitation Extremes in Tropical Land Areas , 2005 .

[50]  J. Namias.  Some Empirical Evidence for the Influence of Snow Cover on Temperature and Precipitation , 1985 .

[51]  E. Takle,et al.  Concurrent variations of water vapor and temperature corresponding to the interannual variation of precipitation in the North American Regional Reanalysis , 2010 .

[52]  H. Nakamura,et al.  Geographical Dependence of Upper-Level Blocking Formation Associated with Intraseasonal Amplification of the Siberian High , 2005 .

[53]  Brian J. Hoskins,et al.  A new perspective on blocking , 2003 .

[54]  T. Zhou,et al.  Multidecadal Variability of North China Aridity and Its Relationship to PDO during 1900–2010 , 2014 .

[55]  Hui Yang.  The significant relationship between the Arctic Oscillation (AO) in December and the January climate over South China , 2011 .

[56]  Song-You Hong,et al.  Role of sea surface temperature and soil-moisture feedback in the 1998 Oklahoma–Texas drought , 2000, Nature.

[57]  Tianjun Zhou,et al.  Detecting and understanding the multi-decadal variability of the East Asian Summer Monsoon: Recent progress and state of affairs , 2009 .