内江市近43年来日照时数变化趋势预测研究

Trend Prediction of Change of Sunshine Hours in Neijiangin the Recent 43 Years

利用内江市1971-2013年日照时数及气温、降水、水汽压、低云量和总云量等逐日气象统计资料,采用线性倾向估计与检验、R/S、马尔可夫链等方法分别对内江市日照时数不同时间尺度进行分析,并对影响日照时数的气象因子进行了探讨.结果表明:近43年内江市的日照时数年际变化趋势为逐渐减少;从季节变化来看,日照时数在夏季的减少趋势最为显著;日照时数月变化在43年中主要表现为夏半年高于全年平均水平.同时,R/S分析中Hurst系数均大于0.5,存在明显的Hurst现象,再次说明内江市未来日照时数将呈现持续下降趋势.经过马尔可夫链预测内江市未来日照时数维持在1001.6h-1152.9h的概率最大,周期为平均每隔2.4802a出现一次.最后通过相关分析得到内江市年日照时数与气温呈显著的正相关,与降水量和总云量呈显著的负相关,其中与总云量呈极显著的负相关.

Based on the recorded statistics including sunshine hours, temperature, precipitation, vapor pressure, low and total cloud cover, assisted by scientific methods including mainly linear trend estimate and test, R/S, and Markov chain, the a- nalysis is focused on different time scales of sunshine hours in Neijiang from 1971 to 2013, and the meteorological factors which influence the sunshine hours are compared. The results show that over the past 43 years the sunshine hours in Neijiang has gradually dropped; in terms of seasonal changes, sunshine hours in summer decreases most sharply; In terms of monthly change, sunshine hours in the summer half year are longer than that of the average level for a whole year. Apart from that, the R/S analysis finds the Hurst coefficients are all over 1/2, which shows an apparent Hurst phenomenon and indicates a further downward trend of sunshine hours in Neijiang in the future. Markov chain predicts that in the future sunshine hours in Neijiang is most likely to vary between 1001.6h to 1152.9h and the interval presents itself as 2. 4802a. Moreover, sunshine hours in Nei- jiang are significantly and positively correlated with temperature, and significantly and negatively correlated with precipitation and most significantly and negatively correlated with total cloud cover.