地理因子在北疆极端气温趋势变化中的作用

论文利用1961-2017年北疆地区37个观测站的逐日气温资料以及高程数据,选取了3类(冷指数、暖指数和极值指数)15项极端气温指数,采用相关分析和灰色关联度统计分析方法,研究了地理因子在北疆极端气温趋势变化中的作用.结果 表明:①北疆地区气候变暖显著,极端气温冷指数呈非常显著的下降趋势,暖指数及极值指数呈显著或非常显...

Possible impacts of geographical factors on long-term trends of extreme temperature indices over northern Xinjiang,China

Based on the daily temperature data of 37 stations in northern Xinjiang from 1961 to 2017 and elevation, 15 extreme temperature indices of 3 categories (cold indices, warm indices, and extreme indices) were selected to explore the possible impacts of geographical factors on long-term trends of extreme temperature indices over northern Xinjiang by means of correlation analysis and grey correlation degree. The results show that: 1) Climate warming is significant in northern Xinjiang, the extreme temperature cold indices show a very significant downward trend, and the warm and extreme indices show a significant or very significant upward trend; climate warming is mainly reflected in the decrease of extreme cold event frequency, and the rise of night temperature and extreme low temperature, which has the characteristics of asymmetry of daytime and nighttime changes and imbalance of low and high temperature changes. 2) The trends of extreme temperature indices in the central basin area of northern Xinjiang are the strongest, while relatively small in the mountainous areas. The influence of topography on the long-term trends of warm indices is greater than that of cold indices. Altitude has a great influence on the frequency of extreme temperature events. 3) The meridional distribution of the trends of extreme temperature indices is the dominant pattern of their spatial distribution. The tendency variations of extreme temperature indices in northern Xinjiang are greater in the north than in the south, and greater in the west than in the east. The biggest difference of tendency variation between the north and the south is in the central part of Northern Xinjiang, and the difference has a negative correlation with altitude, which indicates that latitude has little influence on the long-term trends of the extreme temperature indices in mountainous areas, while it is an important factor in the basin. In the meridional direction, the increasing trend of hot nights has a lower correlation with altitude, while the other indices have a higher correlation with latitude in the east than in the west of northern Xinjiang. 4) Geographical factors have significant influences on long-term trends of extreme temperature indices (the grey correlation degrees are greater than 0.6, which means a high correlation), and the influences of geographical factors on warm indices are greater than cold indices. The influences of geographical factors on the cold indices are stronger in the mountainous and hilly areas, while the influences on the warm indices are mainly manifested in the hilly and basin areas with relatively flat terrain.