Trends in day-to-day variability of surface air temperature in China during 1961–2012

Using daily mean, maximum, and minimum surface air temperature (abbreviated as Tmean, Tmax, and Tmin, respectively) data from CN05.2 and the Met Office Hadley Centre observation data-sets for 1961–2012, the trends in day-to-day variability of Tmean, Tmax, and Tmin (abbreviated as DVTTmean, DVTTmax, and DVTTmin, respectively) are examined. It is revealed that the annual trends of DVTTmean, DVTTmax, and DVTTmin are all negative in Northeast China (NEC), and more obvious in North China than in South China. Seasonal trends of DVTTmean are also negative in NEC, except in summer. For DVTTmax, trends are generally more obvious than DVTTmin in all seasons in NEC; moreover, trends in spring are obvious in both the north and the south, but trends in summer and winter are more obvious in the southern region than in the northern part. As far as DVTTmin is concerned, except in autumn, seasonal trends are more obvious in the north than in other regions of the country