定陶日照时数变化特征及影响因子分析

Variation Characteristics of Sunshine Hours and Its Influencing Factors in Dingtao

采用气候倾向率方法,对定陶1970~2015年年、季节、月日照时数序列随时间变化的线性趋势以及对日照有影响的总云量、低云量、相对湿度和雾日数等资料进行了统计分析,结果表明:近46年定陶日照时数年、年代际、季节、月变化均呈显著减少趋势,年日照时数气候变化倾向率为?110.7 h/10a。最高值为2631.1 h,出现在1976年,最低值为1891.5 h,出现在2003年,极值差为739.6 h。年日照百分率倾向率为?2.619/10a,季节日照时数存在明显的差异性,季节间日照时数平均值排列为夏季 >春季 >秋季 >冬季,春季变化最小,夏季变化最大。月平均日照时数变化特征为低-高-低,其中5月的日平均日照时数最高,为8.1 h, 2月最低,为4.9 h,极值差为3.2 h。4、5、6月的日平均日照时数较高,7、8、9月逐渐减少。各月日平均日照时数变化趋势存在很大差异,其中1月减少的最多,3月减少的最少。污染物、气溶胶浓度的增加,云量、相对湿度、雾日数的增多,年平均风速的减小、是影响定陶日照时数减少的重要气候因子。云量、相对湿度、雾日数与日照时数存在明显的负相关,年平均风速与日照时数存在正相关。

Using the climate trend rate method, the linear trend of the time series of Dingtao’s year, season, and month, and the total amount of cloud, low cloud amount, relative humidity, and foggy days that affected the sunshine were analyzed. Statistical analysis shows that the number, duration, season, and month of sunshine change in fixed pottery in the last 46 years have all significantly decreased, and the climate change tendency of annual sunshine hours is –110.7 h/10a. The highest value was 2631.1 h, which appeared in 1976, and the lowest value was 1891.5 h. It appeared in 2003, and the extreme value difference was 739.6 h. The percentage tendency of annual sunshine rate was –2.619 h/10a. There was a significant difference in seasonal sunshine hours. The mean value of sunshine hours during the season was summer >spring >autumn >winter, with the smallest change in spring and the greatest change in summer. The change of monthly mean sunshine hours was low-high-low, with the highest average daily sunshine hours in May, 8.1 hours, the lowest in Febru-ary, 4.9 hours, and the extreme difference was 3.2 hours. The average daily sunshine hours in April, May and June were relatively high and gradually decreased in July, August and September. There is a big difference in the daily average daily sunshine hours in each month, with the most reduction in January and the least in March. The increase of pollutants and aerosol concentrations, the increase of cloud cover, relative humidity, and the number of days of fog, and the decrease of annual average wind speed are important climatic factors that affect the decrease of sunshine hours in Dingtao. There was a significant negative correlation between cloud amount, relative humidity, and the number of days of fog and sunshine hours, and there was a positive correlation between annual average wind speed and sunshine hours.