1961-2010年河北省日照变化分析

Analysis on Change of Sunshine Duration in Hebei Province during the Period from 1961 to 2010

利用EOF、最大熵谱分析、Lepage突变性检验等方法,分析河北省1961-2010年日照时数的变化情况。结果表明:河北省日照时数空间分布差异较大,整体上表现为由北向南呈递减趋势,各区日照时数普遍呈下降趋势,其中中南大部地区下降趋势较为明显,而北部地区日照时数下降趋势相对较小,年日照时数下降趋势异常显著;空间分布上既有"一致型",也存在"南中北型";从时间变化上看,除个别月份外,其他年、季、月日照时数下降趋势均异常显著;Lepage突变性分析结果显示,在1972年和2001年有较为显著的突变现象发生。分析结果还显示,河北省年日照时数具有非常明显的年际变化特征,4.2 a左右的年际变化周期比较明显。影响河北省日照时数减少的主要因子有云量和雾,浮尘并不是引起河北省日照时数下降的主要原因。

In this paper, the change of annual sunshine duration in Hebei Provinc during the period of 1961 - 2010 was analyzed using EOF, maximum entropy spectrum and Lepage test. The results showed that the difference of spatial distribution of annual sunshine duration was significant in the province. Holistically, annual sunshine duration was decreased from the north to the south of the province, it was in a downtrend in most areas of the province, the downtrend was more obvious in most parts of the central-southern area than that in most parts of the northern area, and the downtrend of annual sunshine duration was extremely significant. The spatial distribution of annual sunshine duration was not only similar, but also varied from the south to the north. Temporally, the decrease of annual, seasonal and monthly sunshine duration was extremely significant except that in few months. Lepage test revealed that there was a sharp change of annual sunshine duration in 1972 and 2001. The analyzed results also showed that the there was a significant change and 4.2-year periodicity of annual sunshine duration in the province. The further analyzed results revealed that the main factors resulting in the reduction of annual sunshine duration was cloud cover and fog, and floating dust was not the main reason causing the reduction of annual sunshine duration.