Diagnoses Analysis of Physical Characteristic Changes of Tropical Storm Haima Before and after Its Transformation
By using the data of NCEP, the physical characteristics of tropical st orm ‘Haima' (0421) before and after its transformation are analyzed. The results show that before its transformation, ‘Haima' had a warm core and a sym me tric structure, and after transformation, the storm became more asymmetric and f rontal. In this process, the cold air invaded into storm from the southwestern p art at lowlevel layer. The relative vorticity changed from symmetric positive v alue at all levels beneath 200hPa to asymmetric structure. In the mean time, the mean relative vorticity and divergence in 24h in middle and low levels became b igger and layer became thicker. The height of vertical velocity center changed f rom 600hPa to 500hPa. There were two vaporchannels because of the eastward trough, one came with southwestern flow, and th e other came from the South China Sea with southern flow.