Comparison of seasonal surface temperature trend, spatial variability, and elevation dependency from satellite-derived products and numerical simulations over the Tibetan Plateau from 2003 to 2011

Land surface temperature (LST) and near-surface air temperature products have been commonly used in the studies of global climate change. In this work, we compare satellite-observed LST from Advanced Along-Track Scanning Radiometer (AATSR) and surface skin temperature and 2m air temperature (T2) simulated from High Asian Refined analysis (HAR) to provide an independent overview of the surface/air temperature trend over Tibetan Plateau (TP) region in 2003-2011. We investigate the seasonal trend, spatial variability, and the elevation dependency of LST and air temperature over TP for the last decade. Linear regression method is applied to all data sets to illustrate the warming and cooling trends and variability of temperature over the study area. Our analysis shows that an overall warming slope is 0.04Kyear(-1) in the day trend and 0.05Kyear(-1) in the night and the trend slope is stronger in the simulated HAR data sets than that in the AATSR LST, especially for the night air temperature. However, in regions with elevation above 4000m, the proportion of areas with the warming trend is less than 50% except in autumn from HAR data sets. The Namco and Qomolangma sites show an apparent trend of warming and cooling, respectively. The results from both satellite observations and numerical outputs show that warming trend over the entire TP was not obvious during last decade and the cooling trend was even found in the northeast TP.