Global Validation of MODIS Near-Surface Air and Dew Point Temperatures

This analysis is the first global validation of the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived near-surface air temperature and dew point estimates, which both serve as crucial input data in models of energy, water, and carbon exchange between terrestrial ecosystems and the atmosphere. By hypsometrically interpolating the MOD07 Level-2 atmospheric profile product to surface pressure level, we obtained near-surface air temperature and dew point observations at 5 km pixel resolution. We compared these daily data, retrieved over a 14-year record, to corresponding measurements from 109 ground meteorological stations (FLUXNET). Our results show strong agreement between satellite and in situ near-surface air temperature measurements (R-2 = 0.89, root-mean-square error = 3.47 degrees C, and bias = -0.19 degrees C) and dew point observations (R-2 = 0.76, root-mean-square error = 5.04 degrees C, and bias = 0.79 degrees C) with insignificant differences in error across climate zones. This validation is among the earliest assessments of the reprocessed, crosstalk-corrected Collection 6.1 Terra MODIS data and provides support for widespread applications of near-surface atmospheric data.