2010年安徽省高速公路一次连续性大雾过程初探

Study on A Long-drawn Heavy Fog of Freeway in Anhui of 2010

利用2010年9月才建成的安徽省高速公路加密自动气象观测站网资料,以及NOAA16极轨气象卫星和其他常规资料,对2010年11月16～17日安徽省高速公路一次大雾天气过程进行分析,探讨此次大雾形成的成因。结果表明,此次大雾过程是在有利的大尺度背景下发生的,大雾发生前降水有利近地面湿度增加,降水后高压控制有利夜里地面辐射降温;在湿度条件较好情况下,低层浅薄逆温就能形成雾;逆温明显时,即使湿度条件不是很好,也能形成雾。通过逐时对比检验发现,高速公路观测站网资料可信度较高,对预报大雾有参考价值;气象站上没有出现大雾时,气象站所在县市内的高速沿线上时有大雾发生,高速上观测信息大大弥补了气象站观测的时空密度不足;高速上大雾生成时间较气象站观测到的平均偏早3 h左右,可提高市、县级台站大雾预报预警时效和准确率。

Using the new encrypted auto station data generated in September 2010 of highway,and NOAA16 polar orbiting meteorological satellite date,routine meteorological observation to analyze a dense fog process in Anhui Province during November 17-18,2010,and causes for the formation of the fog were discussed.It was found that the dense fog was produced in the favorable weather background,the rainfall occurred in previous period is propitious to the vapor condition,under the high pressure control at night was conducive to the radiation cooling;With better humidity conditions,fog can formed in the case of low-level shallow inversion;The fog generated even if the humidity conditions are not very good when the inversion is significant.By hourly comparing test we found that highway data have higher confidence,it is a valuable reference for fog forecasting.When the fog does not appear on the weather station,the fog occurs on freeway auto station located within the county,freeway station observation information greatly make up for the lack of space-time density on weather station.The time fog generated in highway is about 3 hours earlier than the weather observation,it can improve the fog forecasting in warning time and accuracy.