Global Land Data Assimilation System data assessment using a distributed biosphere hydrological model

• Published in: Journal of hydrology (Amsterdam) Vol. 528; pp. 652 - 667
• Main Authors: Qi, Wei, Zhang, Chi, Fu, Guangtao, Zhou, Huicheng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2015
• Subjects: Accuracy; Data assimilation; Energy cycle; Fluxes; GLDAS; Grounds; Heat flux; Land; Land surface temperature; Meteorological data; MODIS; Spatial distribution; Water cycle; WEB-DHM; Meteorological data; WEB-DHM; Energy cycle; GLDAS; MODIS; Water cycle
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2015.07.011

•Both input and output data of GLDAS are evaluated.•GLDAS downward solar radiation and wind speed data are overestimated.•Correction equations are developed to revise solar radiation and wind speed.•GLDAS land surface temperatures are highly accurate.•Seasonal and spatial distributions of fluxes are accurate after corrections. Observed water and energy fluxes are sparse in many regions of the world. The overall aim of this study is to demonstrate the applicability of Global Land Data Assimilation System–Noah (GLDAS/Noah) data for basin scale water and energy studies in terms of input, output, seasonal and spatial distributions. A Water and Energy Budget-based Distributed Hydrological Model (WEB-DHM) is employed to evaluate the output of GLDAS/Noah and the simulations of seasonal and spatial distributions of fluxes after calibration with discharges and MODIS land surface temperatures (LSTs) in a semiarid catchment. GLDAS/Noah air temperatures and humidity agree well with observations, but GLDAS/Noah overestimates downward solar radiation and wind speed. LSTs and upward long wave radiation from GLDAS/Noah and WEB-DHM are comparable, but GLDAS/Noah shows larger upward shortwave, net radiation, latent heat, sensible heat fluxes and smaller ground heat flux amplitude. Two correction functions are developed for downward solar radiation and wind speed. The accuracy of discharges and LSTs is improved after corrections. The simulated seasonal and spatial distributions of water and energy fluxes and states (LSTs, evapotranspiration, surface, root, deep soil wetness, ground heat flux, latent heat flux, sensible heat flux, upward long wave radiation and upward shortwave radiation) show high accuracy using corrected GLDAS/Noah data. The findings provide an insight into the applicability of GLDAS/Noah.