Characteristics of Hot Weather and Its Influence Factors from 1951 to 2015 in Hangzhou of Zhejiang Province
Based on daily meteorological data during 1951-2015 and global solar radiation observations during 1993-2014 in Hangzhou of Zhejiang Province,three indicators including high temperature,warming night and heat index,were calculated to study the characteristics of hot weather in recent 65 years.A simple hot weather forecasting model was established based on 08:00 BST data such as solar radiation,air temperature and relative humidity.The results are as follows:(1)The occurring days of high temperature,warming night and hot weather increased gradually from 1951 to 2015,and the increasing rate changed considerably after the year 2000.High temperature weather occurred mainly in July and August with the frequency of 86.8%.The heat index showed the impact of humidity on human body,and air temperature corresponding to heat threshold descended with increase of relative humidity.(2)Air temperature,relative humidity and global solar radiation at 08:00 BST presented a significant correlation with high temperature weather.And high temperature weather tended to occur when air temperature was more than 28.0 ℃,relative humidity was less than 70.0%and global solar radiation was more than 0.8 MJ·m-2.(3)The hot weather forecasting model was established based on three associated factors using Logic regression,and the accuracy rate of historical forecast reached 87.0%.
Hangzhouhigh temperature weathervariation characteristicsmeteorological factors