主办单位:中国气象局沈阳大气环境研究所
国际刊号:ISSN 1673-503X
国内刊号:CN 21-1531/P

Journal of Meteorology and Environment ›› 2023, Vol. 39 ›› Issue (1): 55-64.doi: 10.3969/j.issn.1673-503X.2023.01.007

• Articles • Previous Articles     Next Articles

Influence of the change of visibility observation method on the statistics and identification of fog and haze in the Beijing-Tianjin-Hebei region

Gang ZHU1(),Jiang-bo LI1,*(),Zhuo SUN1,Shuo-fei WANG2   

  1. 1. Hebei Meteorological Observatory, Shijiazhuang 050021, China
    2. Equipment Center of Hebei Meteorological Service, Shijiazhuang 050021, China
  • Received:2021-09-07 Online:2023-02-28 Published:2023-03-27
  • Contact: Jiang-bo LI E-mail:zgzggzgz@126.com;ljbwave@aliyun.com

Abstract:

Based on the visibility and conventional ground observation data of 177 stations in the Beijing-Tianjin-Hebei region during the period from 2000 to 2018 which is divided into three stages of 2000-2013, 2014, and 2015-2020 when the human visual measurement (HM), the instrumental derived measurement (IM) and the joint observation of HM and IM are adopted, respectively, the visibilities measured by HM and IM were compared and analyzed.The cold and the warm season were respectively defined as the period from November to April of the following year and from May to October.The results show that the annual average visibilities measured by IM at 08:00 and 14:00 are lower than those measured by HM.In the cold season, the measured monthly average visibility at 08:00 by IM is lower than that by HM, and the difference between two methods at 14:00 is significantly smaller than at 08:00.In the warm season, the visibility at 08:00 measured by IM is lower than that by HM, but the difference is generally lower than that in the cold season and is the smallest in May.In 2014, fog and haze occur frequently from January to April.The visibilities at 08:00 and 14:00 measured by IM are obviously less than those by HM.From May to December when there is less haze, the visibilities of more than half stations measured by IM are greater than those by HM.When the visibility is below 12 km, the measured values by IM are less than those by HM, and when the visibility is above the 12 km, the measured values by IM are greater than those by HM.When the visibility is less than 1 km, the measured values by IM are close to those by HM.There is an inverse correlation between visibility and relative humidity.When the visibility is less than 0.5 km, the relative humidities measured by IM and HM range from 93% to 96%, but with the increase of visibility, the relative humidity measured by IM is more scattered than that by HM.After the observation is changed from HM to IM, the occurrence frequencies of fog and haze increase obviously, especially for haze.The high incidence area of fog measured by IM and HM both are distributed along the Beijing-Guangzhou railway in the Beijing-Tianjin-Hebei region, but the haze high incidence area moves eastward from the shallow mountain area of the south-central Taihang Mountain to the plain to the line of Beijing-Guangzhou Railway.

Key words: Visibility, Observation method, Fog, Haze, Relative humidity

CLC Number: