荆门市近60年日照时数变化特征及其影响因素
The Variation Characteristics and Influencing Factors of Sunshine Duration in Jingmen Municipality During 1961 to 2017
中文摘要：
对荆门市境内荆门、钟祥、京山三站1961—2017年逐月日照时数、总云量、低云量、水汽压、相对湿度、能见度资料进行统计分析，结果表明，荆门、钟祥两站年、季日照时数均为显著的减少趋势，其中减少速率最大的是日照时数，夏季减少最多，秋、冬季次之，春季最小；20世纪60—70年代日照充沛，80年代为过渡时期，90年代以后日照时数减少的趋势加剧。京山站夏季减少趋势显著，秋、冬两季为不显著的减少趋势，春季为不显著的增加趋势。年日照时数异常出现过11站次，季日照时数异常出现过33站次，均以异常偏多为主；能见度显著下降是造成年/季日照时数减少的最主要原因，总云量、相对湿度和水汽压增加也是个别季节、个别站点日照时数减少的原因；京山站日照时数下降趋势小于荆门、钟祥两站的原因，主要是由于能见度下降趋势较小，这可能与京山县的地理环境以及经济发展模式对环境的破坏较小有关。
中文关键词：
日照时数，气候倾向率，影响因子
KeyWords：
sunshine duration, climatic trend rate, influencing factors
Abstract：
Statistical analyses were done for data collected from three observational stations in Jingmen municipality from 1961 to 2017. The analyzed data include monthly sunshine duration, total cloud amount, low-level cloud amount, vapor pressure,relative humidity, and visibility. The results indicated that the sunshine duration of Jingmen station and Zhongxiang station was significantly reduced with time, with the greatest reduction rate occurring in summer when the sunshine duration was the most, followed by autumn and winter, and the lowest reduction rate in spring. The sunshine duration was abundant during the 60s and 70s. It started to decline during the 80s and decreased remarkably since the 90s. At Jingshan station, the decrease in sunshine duration was significant in summer but not significant in autumn and winter. For the spring, however, there was a slight (not significant) increase in sunshine duration. A significant decrease in visibility contributed mainly to the reduced annual/seasonal sunshine duration, while the increase of total cloud cover, relative humidity and water vapor pressure also partly explained the decrease of sunshine duration in individual seasons and stations. The lower decreasing rate of sunshine duration in Jingshan station compared to the Jingmen station and zhongxiang station was mainly attributed to the smaller decrease of visibility in Jinshan station which could be related to the geographical environment and the economic development model of Jingshan county.