摘 要: | This study examines spatial and temporal changes in 16 extreme temperature indices at 37 weather stations in Xinjiang andtheir associations with changes in climate means during 1961–2008. Linear regression analyses reveal that significant increasingtrends in temperature were observed over Xinjiang, with the rate of 0.13 °C/decade, 0.24 °C/decade, and 0.52 °C/decadefor annual mean temperature, annual maximum, and minimum temperature, respectively. Annual frequency of cool nights(days) has decreased by -2.45 days/decade (-0.86 days/decade), whereas the frequency of warm nights (days) has increasedby 4.85 days/decade (1.62 days/decade). Seasonally, the frequencies of summer warm nights and days are changing more rapidlythan the corresponding frequencies for cool nights and days. However, normalization of the extreme and mean seriesshows that the rate of changes in extreme temperature events are generally less than those of mean temperatures, except forwinter cold nights which are changing as rapidly as the winter mean minimum temperatures. These results indicate that therehave been seasonally and diurnally asymmetric changes in extreme temperature events relative to recent increases in temperaturemeans in Xinjiang.
|