The study of changing characteristics of the winter temperature and extreme cold events in China over the past six decades

摘要

By using winter (December-February) daily temperature at 1629 meteorological stations over China during 1960/61-2017/18, spatial-temporal changes and probability distribution characteristics of winter temperature and extreme cold events in China were analysed, with a special emphasis on the warming hiatus in China. The results are as follows: (1) the winter temperature in China showed an overall upward trend during the past six decades. However, since the winter of 2006 (so-called the warming hiatus period), the winter temperature in China has remained stable and even decreased slightly. (2) There is an obvious difference in winter temperature between South China and North China. North China witnessed a more obvious temperature rise during the warm period (1986-2005) than South China did. However, since 2006, winter temperature in most parts of North China has dropped slightly, with a marked increase in extreme cold events. In contrast, South China did not undergo an obvious temperature drop during the hiatus period. (3) The range of temperature change in North China is larger than that in South China. The range of minimum temperature is also wider than that of maximum temperature, with a noticeable increase in extreme low temperature events since 2006. In such situation, North China is more likely to encounter extreme low temperature events, such as cold wave and low temperature weather. (4) China has experienced an increase in extreme cold events during the hiatus period. There is an obvious upward trend in regional long-lasting extreme cold events (3-5 and 11-20 days duration). Consequently, this study has revealed that winter temperature and frequency of extreme cold events in China was not only influenced by global warming, with a persistent warming, but also showed an obvious inter-decadal variation which is associated with the natural forcing. It indicates that the natural forcing factor is also a main factor influencing and modulating the winter temperature change at the inter-decadal scale at the regional scale as China even in the era of the global warming caused by anthropogenic forcing.