| Based on air temperature, air vapour pressures, relative humidity, precipitation, radiation, foggy day and thunderstorm day data of Nanjing meteorological station form 1961 to 2005. The influence of urbanization on Nanjing's urban climate was particularity investigated. The conclusion can be drawn as follows:1. The influence to temperature because of urbanization in Nanjing can be drawn as follows: (1) Nanjing has the obvious urban heat island effect. (2)The UHI intensity of Nanjing is about 0.5℃generally, the high value of UHI intensity manifests in the lowest air temperature and its extreme may reaches about 6℃. (3)The UHI effect in Nanjing has obvious seasonal and daily change characteristics; UHI intensity of summer half year is higher than that of winter half year and that in nighttime is higher than in daytime. (4)Along with urban scale development, UHI intensity of Nanjing is increasing, and is most obvious in the 20th century 80-90 ages, The UHI effect had the distinct improvement after 2000 because of enhancement of Nanjing urban construction level and virescence level.2. The influence to air vapour pressure and relative humidity because of urbanization in Nanjing can be drawn as follows: (1) Nanjing has the obvious urban dry island and urban moisture island effect. (2) It exhibiting the obvious urban dry island effect on annual mean air vapour pressures and relative humidity, the center of urban dry island is Nanjing and Jiangning area. (3) The grades intensity of urban dry island and urban moisture island of Nanjing is lesser, It's dominant by feebleness dry island and feebleness moisture Island. (4) Urban dry island intensity of Nanjing has obvious seasonal characteristics, it is stronger in spring and autumn while is weakest in summer. (5) The daily change characteristics of urban dry island intensity is obvious, it's strongest at 14 o'clock but weakest at 02 o'clock. In summer, it has bigger probability stronger intensity of urban dry island and moisture island than other three seasons at 4 observations time. (6) Generally with the expending of urban dimension, Urban Dry Island intensity of Nanjing is increasing.3. The influence to precipitation because of urbanization in Nanjing can be drawn as follows: (1) The precipitation has the weak increase tendency along with the age in Nanjing seven station, and the tendency is not salience. The precipitation is biggest in 80's and 90's, the statistics of year precipitation data indicated that it not has obvious urban rain island effect in Nanjing.(2) The precipitation has remarkable difference only between Nanjing and Liuhe. Humanity behavior obvious influence the precipitation difference between urban and suburb, precipitation Occurred on the working day must be more than on Sunday , and the influence is more district in the urban than in the suburb. (3) The probability of occurred faintness rain, big and especially big rainstorm is increase, and the probability of happened Strong precipitation is more in the urban than in the suburb, while the light rain is contrary.4. The influence to solar radiation, fog days and thunderstorm days because of urbanization in Nanjing can be drawn as follows: (1) The direct solar radiation and global radiation in Nanjing has obvious reductive tendency, but the turbidity factor is increases along with the city development. (2) The number of fog days is more in the urban station than in the suburb station, and it is reduced between in the urban station and in the suburb station after 80's, but the number of flog days is enhancive after 2000 in the urban station. The difference of the number of flog days between in the urban station and in the suburb is obvious increases from 1975 to 1990, while is reduced after 1990. (3) The number of thunderstorm days has obvious wavy reduce tendency, the drop speed in the urban station is more rapidness than in the in the suburb station.
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