| 摘 要： | This study examines spatial and temporal changes in 16 extreme temperature indices at 37 weather stations in Xinjiang and
their associations with changes in climate means during 1961–2008. Linear regression analyses reveal that significant increasing
trends in temperature were observed over Xinjiang, with the rate of 0.13 °C/decade, 0.24 °C/decade, and 0.52 °C/decade
for 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 increased
by 4.85 days/decade (1.62 days/decade). Seasonally, the frequencies of summer warm nights and days are changing more rapidly
than the corresponding frequencies for cool nights and days. However, normalization of the extreme and mean series
shows that the rate of changes in extreme temperature events are generally less than those of mean temperatures, except for
winter cold nights which are changing as rapidly as the winter mean minimum temperatures. These results indicate that there
have been seasonally and diurnally asymmetric changes in extreme temperature events relative to recent increases in temperature
means in Xinjiang.
|
