Contributions of surface solar radiation and precipitation to the spatiotemporal patterns of surface and air warming in China from 1960 to 2003

Although global warming has been attributed to increases in atmospheric greenhouses gases, the mechanisms underlying spatiotemporal patterns of warming trends remain under debate. Herein, we analyzed surface and air warming observations recorded at 1977 stations in China from 1960 to 2003. Our results showed a significant spatial pattern for the warming of the daily maximum surface (Ts-max) and air (Ta-max) temperatures, and the pattern was stronger in northwest and northeast China and weaker or negative in South China and the North China Plain. These warming spatial patterns were attributed to surface shortwave solar radiation (R-s) and precipitation (P), which play a key role in the surface energy budget. During the study period, R-s decreased by -1.50 +/- 0.42 W m(-2) 10 yr(-1) in China, which reduced the trends of Ts-max and Ta-max by about 0.139 and 0.053 degrees C 10 yr(-1), respectively. More importantly, the decreasing rates in South China and the North China Plain were stronger than those in other parts of China. The spatial contrasts in the trends of Ts-max and Ta-max in China were significantly reduced after adjusting for the effect of R-s and P. For example, after adjusting for the effect of R-s and P, the difference in the Ts-max and Ta-max values between the North China Plain and the Loess Plateau was reduced by 97.8 and 68.3 %, respectively; the seasonal contrast in Ts-max and Ta-max decreased by 45.0 and 17.2 %, respectively; and the daily contrast in the warming rates of the surface and air temperature decreased by 33.0 and 29.1 %, respectively. This study shows that the land energy budget plays an essential role in the identification of regional warming patterns.