Phase composite analyses are conducted to investigate the possible effect of the Madden–Julian oscillation(MJO)on the spring rainfall anomalies in East China by using the Real-time Multivariate MJO(RMM)index from Australian Meteorological Bureau.The results show that the rainfall anomalies over the mid-and lower-valley of Yangtze River are positive when the MJO shifts eastward to the mid-and eastern-Indian Ocean,and anomalous precipitation over South China are positive when the MJO moves further eastward to the maritime continent,whereas spring rainfall anomalies over East China are negative in the other MJO episodes.The MJO impacts on the precipitation over East China result from the changes in large-scale atmospheric circulation as well as vorticity and water vapor transportation in the mid-and lower-troposphere.
Phase composite analyses are conducted to investigate the possible effect of the Madden–Julian oscillation(MJO)on the spring rainfall anomalies in East China by using the Real-time Multivariate MJO(RMM)index from Australian Meteorological Bureau.The results show that the rainfall anomalies over the mid-and lower-valley of Yangtze River are positive when the MJO shifts eastward to the mid-and eastern-Indian Ocean,and anomalous precipitation over South China are positive when the MJO moves further eastward to the maritime continent,whereas spring rainfall anomalies over East China are negative in the other MJO episodes.The MJO impacts on the precipitation over East China result from the changes in large-scale atmospheric circulation as well as vorticity and water vapor transportation in the mid-and lower-troposphere.