基于WRF模式对华北一次飑线过程中雷电活动的间接和直接模拟研究

将非感应起电机制和放电参数化方案耦合到WRF模式的Morrison双参数微物理方案中,并在模式中引入了闪电潜势指数LPI,在此基础上模拟了2009年6月16日华北一次飑线过程,讨论模式对闪电活动再现能力。模拟结果显示,模式能够较好地再现雷达回波和降水分布特征,说明模式对此次飑线过程的宏观和微观特征具有一定的模拟能力。利用计算闪电潜势指数LPI的间接模拟,能够指示出大致的闪电分布特征,但闪电潜势指数LPI分布范围明显大于实际闪电落区;而通过耦合电过程的WRF模式直接输出闪电密度的直接模拟,模拟结果与实际闪电密度分布的对应关系较好,但由于模式中输出的闪电密度为总闪电密度,与观测地闪密度资料相比,模拟的闪电密度偏大。

Indirect and direct simulation on lightning activity of a squall line process in North China based on WRF model

The non-inductive charging mechanism and simple discharging parameterization scheme were coupled to Morrison microphysical scheme in WRF model, and the Lightning Potential Index (LPI) was introduced to the model, on these bases, a squall line occurred in North China on June 16, 2009 was simulated, in order to determine the reappearance ability of the lightning flash density by the proposed model. Results show that the model can quite better recreate the observed radar echo and precipitation distribution features, therefore, it is able to simulate the macroscopical and electrical features of this squall line. The calculation of indirect simulation of LPI represents roughly the lightning distribution feature, but the LPI distribution covers obviously the wider range than the observed lightning distribution. The direct simulated lightning density reproduces the observed lightning distribution reasonably. Due to the total lightning density given in model output, it is nature to find larger C-G lightning density than the observed one.