Characteristics of Interdecadal Variability in the Difference Between Surface Temperature and Surface Air Temperature in Southeast and Northwest China

The characteristics of the interdecadal variability in the differences between surface temperature (T_s) and surface air temperature (T_a) are analyzed, using daily-observed surface temperature and surface air temperature data from 1960 to 2006. Analysis results show that there is a clear interdecadal variability in T_s-T_a in Southeast and Northwest China. Before the late 1970s, the T_s-T_a anomalies were mostly positive in Southeast China, but they mostly became negative after this period. In contrast, in Northwest China, the T_s-T_a anomalies were mostly negative in spring and summer before the late 1970s, but became largely positive after this time. The opposite trend can be seen in the variability of T_s-T_a in Northwest China in the winter. However, in the autumn in Northwest China, the interdecadal variability of T_s-T_a was not as clear as during the other seasons. The analyzed results of T_s and T_a over the study period show that their contributions to interdecadal variability of in T_s-T_a differed between different seasons.