资源环境科技发展态势分析平台

The terminal velocity of graupel (V_g) affects the development of strong convective systems, but there are large uncertainties in the description of V_g in numerical models. We examined the effects of V_g on the structure and evolution of a strong convective system in Beijing using the Advanced Research Weather Research and Forecasting Model (ARW-WRF). Multiple simulations were performed to test the sensitivity of the model to different fitting equations of V_g in the WDM6 microphysics scheme. We found that a larger value of V_g significantly increased the precipitation rate. With respect to the distribution of hydrometeors, a larger value of V_g reduced the centroid and peak value of snow, graupel and cloud water above the freezing layer, while the centroid of rainwater decreased and the peak value increased. This promoted the conversion of ice particles into rainwater. As a result of the complexity of heat exchange in cloud microphysical processes, the effects of V_g on the heat budget of precipitation particles within clouds have strong nonlinear characteristics.