Observation And Simulation Study Of The Stratiform And Embedded Convective Clouds Of Northeastern China

The stratiform and embedded convective clouds is one of the main clouds in china, it’s dynamic and thermal characteristics are more complex than the single stratiform clouds or convective clouds. The studies of this type of cloud are very useful to enhance the forecasting level, and also helpful to support the operation of weather modification.This paper using conventional meteorological data and Doppler radar data, through the observation and analysis of the stratiform and embedded convective clouds at July1,2010, from satellite cloud picture, radar reflectivity factor, radial velocity field and thermal conditions etc, described the macro and micro characteristics of this process. Then, using the NCEP global reanalysis data and WRF model, selete three stage, analysis the process from formation to dissipation, preliminary elaborated the formation mechanism of the the stratiform and embedded convective clouds from dynamic and thermodynamic aspect.In this paper, a typical process of The stratiform and embedded convective clouds is simulated, the results show:from the radar reflectivity pictures, we can find the orientation of cloud system is southwest-northeast, there are some strong echoes in the stratiform cloud, the maximum echo intensity is about40dBz.There has very obvious vapor exchange process no matter it is convective cloud embedded in the stratiform clouds or the merging process of the several convection clouds. The convective clouds did not develop immediately, the moisture content is about0.8g/kg and updraft is less than10m/s. when the stratiform clouds develop over the convective clouds, the water vapor environment is plenty than before, the configuration of the convergence and divergence at high and low level is changed. Bring about the embedded cloud. In the process of the convective cloud development, the updraft in the cloud is leaned, when it is change to vertical updraft, the embedded cloud will reach its maturation period.When we analysis the stability, we can find that this process belongs to the potential instability, it is advantageous to develop and form convection. The pseudo-equivalent potential temperature is decreasing with the ascending of the height. The value of the CAPE is small. From the analysis of the energy transfer, we can find that the embedded convective cloud is developing when it is in the accumulation region of energy, while if it is in the unfavorable position of the energy transfer, the intensity of the convective cloud will gradually weakened and then it will be merged or dissicape. So it is easy to find that the transfer of the energy is in effect to the process of the stratiform and embedded convective clouds. It needs more cases to verification.