Long-Term Surface Air Temperature Trends Over Mainland China

Based on a dataset of national reference and basic stations, which have been quality controlled and inhomogeneity processed, updated surface air temperature (SAT) series of the past 67 (1951–2017) and 113 (1905–2017) years for mainland China are constructed and analyzed. The new temperature series show significant warming trends of 0.24°C/10yr and 0.09°C/10yr respectively for the two periods. The rapid regional warming generally begins from the mid-1980s, about a decade later than the northern hemisphere average SAT change. Warming during the period of 1951–2017 is larger and more significant in the northeast, north, northwest and the Qinghai-Tibetan Plateau, and the most significant SAT increase usually occurs in winter and spring except for the Qinghai-Tibetan Plateau where winter and autumn undergo the largest warming. The slowdown of the warming can be clearly detected after 1998, especially for autumn and winter. The effect of urbanization on trends of the region averaged annual and seasonal mean SAT as calculated from the national reference and basic stations has not been adjusted, despite it being generally large and significant. In north China, the increasing trend of annual mean SAT induced by urbanization for the national stations is 0.10°C/10yr for the period 1961–2015, accounting for at least 31% of the overall annual mean warming. The contribution of urbanization to the overall warming of the past half century in Mainland China has also been summarized and discussed referring to the previous studies.