基于高分辨率资料的南阳市冬半年大雾特征分析  

Characteristics Analysis of Heavy Fog Events in Nanyang in Winter Half Year Based on High-resolution Data

作　　者：贺哲[1,2] 竹磊磊 席乐[2] 李新梅 王春晓 张永涛 王珏[4] He Zhe;Zhu Leilei;Xi Le;Li Xinmei;Wang Chunxiao;Zhang Yongtao;Wang Jue(CMA·Henan Key Laboratory of Agrometeorological Support and Applied Technique,Zhengzhou 450003,China;Henan Meteorological Observatory,Zhengzhou 450003,China;Henan Climate Center,Zhengzhou 450003,China;Nanyang Meteorological Office,Nanyang 473000,China;Henan Meteorological Bureau,Zhengzhou 450003,China)

机构地区：[1]中国气象局·河南省农业气象保障与应用技术重点开放实验室,郑州450003 [2]河南省气象台,郑州450003 [3]河南省气候中心,郑州450003 [4]南阳市气象局,河南南阳473000 [5]河南省气象局,郑州450003

出　　处：《气象与环境科学》2023年第6期1-9,共9页Meteorological and Environmental Sciences

基　　金：河南省气象局科学技术研究项目(KZ201705);中国气象局·河南省农业气象保障与应用技术重点实验室应用技术研究基金项目(KQ202106)。

摘　　要：利用南阳市逐小时地面观测资料、MWP967KV型地基微波辐射计资料及ERA5等高分辨率资料,对南阳市冬半年64个大雾天气过程进行特征分析。结果表明:12月不仅是大雾出现最频繁的月份,也是大雾最严重的月份。无论前期是否有降水,大雾均有可能出现。近地面相对湿度达到90%以上时,能见度不一定都会达到大雾的级别,也可能是轻雾。前24 h内有降水时的大雾时段的液态水含量≥0.2g·m^(-3)的气层厚度明显大于前24 h内无降水时的,而近地面液态水含量的最大值两者差异不显著。大雾发生时,近地面层为湿层,再向上则覆盖有一个干空气层;近地面多为辐合及正涡度,既有下沉运动,也有上升运动,但以下沉运动居多,且垂直速度绝对值一般都在0.1Pa·s^(-1)以下,或接近于0Pa·s^(-1)。大雾时段近地面冷平流和暖平流都有可能存在,逆温或等温层对于大雾的形成具有更为重要的作用。Based on the high-resolution datasets of hourly surface observations,MWP967KV ground-based microwave radiometer and ERA5,the characteristics of 64 heavy fog processes in Nanyang in winter half year are analyzed.The results show that December is the month to see heavy fogs most frequently and most serious.Whether there is precipitation in earlier stages or not,heavy fogs are always likely to occur.Even though relative humidity near the surface exceeds 90%,visibility is not necessarily of the grade of heavy fog,and it may be of mist.When there is precipitation within 24 hours before heavy fogs,the atmospheric layer with liquid water content≥0.2 g·m^(-3) during the heavy fog period is thicker than that of no precipitation in the earlier stage,but there is no significant disparity between the maximum values of liquid water content near the surface in the two conditions.When heavy fog occurs,there is a wet layer near the surface,over which is a dry layer.In general,near the surface,there is convergence and positive vorticity in most cases,and there is descending motion and ascending motion,but most of them are descending motions.The absolute values of vertical motions are usually less than 0.1 Pa·s^(-1) or close to 0 Pa·s^(-1).During the heavy fog period,it is possible for cold advection and warm advection to exist near the surface.The temperature inversion layer or isothermal layer plays a more important role in the occurrence of heavy fogs.

关 键 词：南阳 大雾 地基微波辐射计 ERA5 

分 类 号：P426.4[天文地球—大气科学及气象学]