北京地区一次冬季平流雾过程数值模拟分析

 利用美国新一代非静力平衡中尺度数值预报模式WRFV2.1系统对发生在2006年1月14日的北京地区平流雾进行数值研究,分析平流雾发生、发展和消散机制.结果表明,北京地区的偏东南风将东、东南、南部的暖湿空气向西北推进,遇到较冷的下垫面冷却饱和凝结形成了此次平流雾.持续且不强的偏南风是雾维持的原因之一.由于地面升温,逆温层从地面抬升至低空并稳定维持,是平流雾形成后能维持较久的又一重要原因.冷空气的入侵,导致了此次大雾的消散.WRF模式对平流雾的形势及物理量场的模拟是成功的,显示了WRF模式预报平流雾的潜在能力.

Simulation and analysis of a winter advection fog in Beijing Area

An advection fog on 14 Jan 2006 in Beijing area is simulated and diagnosed with WRF(Weather Research &; Forecasting)nonhydrostatic model.It shows that the advection fog was formed when warm and moist air lied on the SE,E and S of Beijing area moved to the cooler ground.The continues and weak southern wind was one of the factors that the fog could maintain.The other important reason is that inversion layer were lifted from the ground to lower level of the air and maintained.The cold air intrusion resulted in the fog dispersion.Potential ability of prediction the advection fog by WRF model is proved to some extent.