The role of changing multiscale temperature variability in extreme temperature events on the eastern and central Tibetan Plateau during 1960-2008

Variability is a very important inherent characteristic of climate and it varies on all timescales. It is also considered an important factor regarding changes of extreme events. On the basis of daily temperature records at 63 stations in the eastern and central Tibetan Plateau during 1960-2008, we examine changes of temperature mean, variability and extremes for the region, and study correlations between multiscale temperature variability and various extreme temperature events. Results show that considering the entire study region, a significantly decreasing trend is observed for intra-annual temperature variability (StdD), whereas a significantly increasing trend is observed for interannual temperature variability (IVT). Further relationships between multiscale temperature variability and temperature extremes over the past 49 years show that IVT is positively correlated with cold/warm nights (TN10/TN90) and warm days (TX90), whereas StdD is positively correlated with cold extremes (TN10/TX10) and negatively correlated with warm extremes (TN90/TX90). Nevertheless, annual mean temperature also plays an important role in the relationships between temperature variability and temperature extremes, for correlations between IVT and cold temperature extremes in two warming periods are quite different. Stations with different temperature trends for mean, variability and extremes in the two warming periods are categorized in the study region, and these temperature characteristics in each category are also affected by local effects, such as elevation, topography and urbanization. However, in strong warming periods, the change of mean temperature still has a dominant effect on extreme temperature events.