Decadal variations of land surface temperature anomalies observed over the Tibetan Plateau by the Special Sensor Microwave Imager (SSM/I) from 1987 to 2008

In this paper, we analyze the standardized anomalies of land surface temperature (LST) retrieved from the Special Sensor Microwave Imager (SSM/I) vertically polarized 37 GHz ($T^v_{B,37~{\rm GHz}}$) brightness temperature over the Tibetan Plateau for the period 1987 to 2008. A radiative transfer model is used to derive LST from SSM/I $T^v_{Bv,37~{\rm GHz}}$, which is calibrated and validated using time series of field measured soil surface temperatures. Additional Plateau-scale verification is performed with monthly LST products from the Moderate Resolution Imaging Spectroradiometer, the Noah land surface model and air temperature measured by Chinese Meteorological Administration. Trend analysis shows that the annual and monthly standardized anomalies are increasing at an averaged rate of 0.5 decade − 1. The highest positive trends are noted over the central part of the Plateau, which is on average 0.80 decade − 1 with a maximum of 1.44 decade − 1. Conversely, a negative trend in the anomalies is found for the Taklamakan desert and the Himalayan foothills with a rate of −0.27 decade − 1 and reaching a maximum of −1.4 decade − 1. In addition, we find that LST anomaly trends on the Plateau are seasonally dependent and increase with the elevation. These observed trends are in agreement with previous studies conducted with in-situ measurements, which demonstrates the use of long-term earth observation programmes for climate studies as has also been articulated in the 2007 IPCC report.