绵阳机场冬季连续浓雾天气成因及特征分析

该文结合Micaps系统平台，NCEP/NCAR的2.5°×2.5°格点的再分析资料及常规资料等对2013年12月28日～2014年1月2日绵阳机场连续浓雾天气过程的天气学环流背景、相关物理量、大气层结和稳定度进行分析,揭示有利于连续浓雾形成和维持的机制及成因。结果表明此次过程发生前700hPa西南气流带来弱暖湿平流为大雾的产生和维持提供了良好的环流背景；中低层充足的水汽及925hPa以下较强的逆温层为大雾维持提供了有力条件；浓雾发生前期，对流层低层风向以东南和偏南气流为主，发生时有弱西北气流扰动，700hPa以下至近地面层均为辐合上升区，700～500hPa为弱辐散下沉区和零辐散区，这种配置使水汽在中低层汇合，有利于稳定性层结的建立与浓雾的维持。

Analysis on Characteristics and Cause of Continuous Heavy Fog in Mianyang Airport

By use of MICAPS system data,NCEP/NCAR 2.5°×2.5° grid point reanalysis data and the routine observation data,we analyzed the synoptic circulation,physical quantities,atmospheric stratification and stability in Mianyang airport which occurred from December 28,2013 to January 2,2014.It revealed mechanisms and the cause of the formation and maintenance of the continuous fog.The results showed that the southwesterly flow on 700hPa bring warm and moist advection which provided the favorable circulation background before this process,sufficient supply of water vapor in middle and low level and the apparent inversion layer below 925hPa provided favorable conditions for the fog maintaining.In the earlier stage of the heavy frog the lower troposphere wind direction maitained southwest or south,as the heavy frog happened,weak northwest flow disturbance occurred,and there was an area of weak convergence ascending below 700hPa,and an area of weak of zero divergence and subsidence during 700hPa to 500hPa.This configuration enabled the convergence of water vapor in middle and low level,and is conducived to the establishment of stable stratification,the maintenanceof the continuous heavy frog.