河南省极端气温时空变化特征分析

Temporal and Spatial Variation Characteristics of Extreme Temperature in Henan Province

本文利用1958~2012年河南省15个地面观测站的最高气温、最低气温等地面观测逐日平均数据,采用一元线性回归、反距离加权差值、Mann-Kendall (M-K)法对河南省极端气温时空变化以及突变进行了更加全面、准确的分析,最终得出以下结论:河南省极端高温指数整体上呈现上升趋势,热持续指数、夏日日数、暖昼日数和暖夜日数的变化倾向率分别为?0.3 d/10a、1.3 d/10a、?0.16 d/10a、2.9 d/10a,而极端低温指数则呈现显著下降趋势,冷持续指数、霜日日数、冷昼日数和冷夜日数的变化倾向率分别为?0.15 d/10a、?3.4 d/10a、?0.4 d/10a、?2.4 d/10a,在2000年以后河南省气候变暖趋势更加明显。河南省极端气温的变化呈现非对称性,与极端高温指数的上升幅度相比,极端低温指数的下降幅度更大,尤其是与夏日日数的上升趋势相比,霜日日数下降趋势十分显著。在空间变化中,暖夜日数、霜日日数和冷夜日数变化倾向率的范围和数值(绝对值)明显大于其他极端指数,空间变化对这三个极端气温指数的影响最为明显,而海拔高度的变化对夏日日数与霜日日数的影响最为显著。极端气温指数的突变主要发生在2000年前后。

The daily average data of the highest and lowest temperatures observed at 15 ground stations in Henan Province from 1958 to 2012 are used to analyze the temporal and spatial changes and ab-rupt changes of the extreme temperature in Henan Province more comprehensively and accurately by means of linear regression, inverse distance weighted difference and Mann Kendall (m-k) method. After analyzing, the conclusions are as follows: The extreme high temperature indices in Henan Province showed an upward trend as a whole. The change tendency rates of heat persistence index, summer days, the percentile value of warm day and the percentile value of warm night were ?0.3 d/10a, 1.3 d/10a, ?0.16 d/10a and 2.9 d/10a, respectively. The extremely low temperature indices showed a significant downward trend, while the cold persistence index, frost days, the percentile value of cold day and the percentile value of cold night showed a significant downward trend. The change tendency rates of the number were ?0.15 d/10a, ?3.4 d/10a, ?0.4 d/10a, ?2.4 d/10a, respectively. And the trend of climate warming in Henan Province is more obvious after 2000. The change of extreme temperature in Henan Province is asymmetric. Compared with the increase of extremely high temperature indices, the extremely low temperature indices have a larger decline. Especially compared with the rising trend of summer days, the downward trend of frost days is very significant. In the spatial variation, the range and value (absolute value) of the percentile value of warm night, frost days and the percentile value of cold night change propensity rates are significantly larger than other extreme exponents. The spatial change has the most obvious influence on the three extreme temperature indices, while the altitude changes to summer days and frost days. The impact is most pronounced. The mutation in the extreme temperature index occurred mainly around 2000.