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 ›› 2022, Vol. 38 ›› Issue (3): 112-118.doi: 10.3969/j.issn.1673-503X.2022.03.013

• Articles • Previous Articles     Next Articles

Low visibility classification based on CART decision tree in Hebei province

Qi YOU1(),Xiao-li QU1,2,*(),Zeng-bao ZHAO1,Jie WANG1,Di ZHANG1,Lin-han YANG1   

  1. 1. Hebei Meteorological Service Centre, Shijiazhuang 050021, China
    2. Key Laboratory of Meteorological and Ecological Environment of Hebei Province, Shijiazhuang 050021, China
  • Received:2021-04-08 Online:2022-06-28 Published:2022-07-23
  • Contact: Xiao-li QU E-mail:369956658@qq.com;hebqx_quxiaoli@126.com

Abstract:

Based on the hourly observation data of 142 national weather stations in Hebei province from 2016 to 2019, a visibility forecast model was constructed for low visibility and high-frequency areas using Empirical Orthogonal Function and CART decision tree classification and regression methods, and a fitting test was carried out.The results show that except in Zhangjiakou, Chengde, and Qinhuangdao, fog days most appear in the areas south of 40°N, with the average peak of annual fog days more than 50 days.The relative humidity, surface temperature, wind speed, and other meteorological factors are significantly correlated with visibility.High correlation factors act as input variables to the forecast model, which is proved to have a good effect on the winter forecast with high accuracies.In summer, the false alarm rates are lower and the differences between day and night are less obvious, with little differences between the three indexes.Whereas in winter, the accuracy rates and false alarm rates are significantly superior to those in the daytime, and the missing alarm rates are slightly higher.The fitting results of three heavy fog processes on December 7-10, 2019, at Shijiazhuang station are good without any fogy time missed.

Key words: Visibility, CART decision tree, Fitting prediction

CLC Number: