水汽场初值调整及其对华南降水预报贡献的研究

RESEARCH ON THE ADJUSTMENT OF INITIAL VALUE IN MOISTURE FIELD AND ITS CONTRIBUTION TO RAINFALL PREDICTION OVER SOUTH CHINA

该文利用ＧＭＳ多通道气象卫星资料推导得到的降水资料估算出的加热率，作为非绝热的非线性正规模初始化过程中的非绝热强迫项，进行风压场的初值调整，再采用一个与模式中的对流参数化方案相反的逆运算方案，进行水汽场的初值调整．以保证初始时刻按模式的物理参数化方案计算得到的加热率与由卫星推导的加热率一致．这一方法在非绝热的非线性正规模初值化的框架中，使初始时刻的水汽场得到调整．既实现了传统的初始化目标，又提高了模式对降水的短时预报效果．对华南的两个个例的试验结果表明该文的方法是有效的．

By using the heating rate,which was calculated from the precipitation data derived from the GMS multichannel meteorological satellite,as the non adiabatic forcing term of the non adiabatic nonlinear normal mode initialization process,the initial values of wind field were adjusted.And then using a counter operation scheme,which was contrary to the model's convective parameterization scheme,the initial values of the moisture field were adjusted to be sure that the heating rate calculated from the model′s physical parameterization scheme was in accordance with the heating rate derivde from the meteorological satellite.The method,which was in the frame of non adiabatic nonlinear normal mode initialization,had the initial vapor field adjusted.Not only has it achieved the goal of the traditional initialization,but also improved the model′s capability of the short time prediction to precipitation.The results of two trials in South China indicate that the method is valid.