The Response Of Soil Surface Temperature To Global Warming In China

We examined the spatiotemporal variation in maximum soil surface temperature, minimum soil surface temperature and diurnal soil surface temperature range and discussed the relationship with maximum and minimum air temperature, sunshine duration, precipitation, total cloud cover, based on data from 421 weather stations from 1965 to 2014. Main conclusion is:1. During the whole study period, the maximum soil surface temperature, minimum soil surface temperature showed increased significantly, increased at the rate of 0.66℃/10a, 0.43℃/10a, respectively, and the increase rate of the maximum and minimum soil surface temperature is higher than maximum and minimum air temperature. Results showed that the diurnal soil surface temperature range decreased significantly (-0.23℃/decade) due to the increase rate of minimum soil surface temperature is faster than maximum soil surface temperature.2. We found the maximum and minimum soil surface temperature had different breakpoints. Maximum soil surface temperature showed significant increases only from 1989 to 1998(0.80℃/10a), there were no obvious change during 1965 to 1987 and 1999 to 2014 periods. Minimum soil surface temperature experienced two significant increasing periods: minimum soil surface temperature showed a significant increasing (0.33℃/10a) during 1965 to 1998, this change is consistent with the minimum air temperature and the rate of increasing is lower than minimum air temperature; and since 1999 minimum air temperature increased rapidly even as increases in air temperature slowed, this is different maximum soil surface temperature, so the diurnal soil surface temperature range declined significantly(-1.24℃/10a) during 1999 to 2014.3. Spatially, maximum and minimum soil surface temperature with rates increasing became slower from north to south. Maximum soil surface temperature increased significantly is highest in Tibetan Plateau (0.65℃/10a), and followed by northeast of China. Minimum soil surface temperature showed increasing significant in 8 climate regions, and had the highest increase rate in northeast of China. Diurnal soil surface temperature range decreased significantly in northeast China, north China plain, east China, southeast China and northwest China, and decrease rate is highest in northeast China.4. Seasonally, maximum and minimum soil surface temperature showed increasing significant in all seasons. Maximum soil surface temperature with the largest warming during spring, minimum soil surface temperature with the largest warming during winter, and the increase of rate is faster others seasons. Diurnal soil surface temperature range largest cooling during winter, and followed by autumn. Spatially with the same latitude, seasonal trend of soil surface temperature is similar with annual trend, and with rates increasing became slower from north to south.5. During the whole study period, indicating that air temperature is dominant effect on maximum and minimum soil surface temperature. After 1999, the total cloud cover increased significantly and regional precipitation played an important role in minimum soil surface temperature and diurnal soil surface temperature range.