An assessment of summer sensible heat flux on the Tibetan Plateau from eight data sets

Abstract

The eight datasets of the summer (June–August) surface sensible heat (SH) flux over the Tibetan Plateau (TP) are compared on the time scales of the climatology, interannual variability and linear trend during 1980–2006. These data sets include five reanalyses (National Center for Environmental Prediction reanalysis, NCEPR1 and NCEPR2, NCEP climate forecast system reanalysis, CFSR, Japanese 25-year reanalysis, JRA, and European Centre for Medium Range Weather Forecasts reanalysis, ERA40), two land surface model outputs (Noah model data of Global Land Data Assimilation System version 2, G2_Noah, and Simple Biosphere version 2 output by Yang et al., YSiB2), and estimated SH based on China Meteorological Administration (CMA) station observations, ObCh. The results suggest that the summer SH on the TP differs from one dataset to another due to different inputs and calculations. Climatologically, the ERA40 and JRA distribute rather uniformly while the other six products show similar regional disparities, that is, larger in the west than in the east and stronger in the north and the south than in the middle of the plateau. The mean magnitude of the SH averaged over the 76 stations above the TP varies considerably among each dataset with the difference of more than 20 W m−2 between the maximum (G2_Noah) and minimum (ObCh). Nevertheless, they are consistent in the interannual variability and mostly show a significant decreasing trend corresponding to the weakening surface wind speed, in spite of the distinct trend for the ground-air temperature difference among the different data sets. These two consistencies indicate the particular availability of the SH products, which is helpful to the relevant climate dynamics research.