The Characteristics of Temporal and Spatial Variations of Heat Sources,Moisture Sinks over the Changjiang-Huaihe Valley in Summer 1999
1999年夏季江淮地区热源和水汽汇时空变化特征

The characteristics of temporal and spatial variation of heat source and moisture sink over the Changjiang-Huaihe valley in summer of 1999 are examined by using the NCEP / NCAR reanalysis data and rainfall record over 87 stations of China (including the observation during the IOP of HUBEX). The precipitation concentrated over the Changjiang valley was from June 22 to July 2 of 1999. During the Meiyu Period, the convective precipitation was dominant over the center of rainfall area, and the atmosphere was mainly heated by the release of condensation latent heat. The main area of Q1, Q2 with large positive value coincide with intensity upward motion and rainfall center. The fluctuation of vertical motion was in-phase with heat source and moisture sink. The mesoscale variations whose period is shorter than 3 days were obvious, but stratiform precipitation was dominant over the Huaihe valley where precipitation was small.