Evaluation of Noah land-surface models in predicting soil temperature and moisture at two tropical sites in India

Abstract

Soil temperature and moisture are important initial conditions in weather and climate models. Owing to the sparsity of observations, surface and subsurface soil temperature and moisture are usually generated using land-surface models (LSMs). Hence, it is important to test the performance of LSMs in predicting these parameters. In the present study, the simulation skill of the three-dimensional Noah LSM is evaluated with respect to soil temperature and moisture at two sites in India, Kharagpur and Ranchi. The model-simulated soil temperature and soil moisture are compared with site observations for a period of 2 years, 2009–2010, at both sites. Soil moisture is reasonably well simulated by the model at all depths and at all time scales in both these sites, showing a dry bias in the monsoon and a wet bias in spring and winter. Soil temperature is usually over-predicted by the model except in the monsoon. It appears that the model has a slower infiltration rate and higher evaporation rate than the actual values.