Prasanna H. Gowda Michael Hobbins Gabriel B. Senay George Paul Thomas Marek Dana Porter Jerry Moorhead 2015 <p><span>The National Oceanic and Atmospheric Administration (NOAA) provides daily reference evapotranspiration (ET</span>_ref<span>) maps for the contiguous United States using climatic data from North American Land Data Assimilation System (NLDAS). This data provides large-scale spatial representation of ET</span>_ref<span>, which is essential for regional scale water resources management. Data used in the development of NOAA daily ET</span>_ref<span> maps are derived from observations over surfaces that are different from short (grass — ET</span>_os<span>) or tall (alfalfa — ET</span>_rs<span>) reference crops, often in nonagricultural settings, which carries an unknown discrepancy between assumed and actual conditions. In this study, NOAA daily ET</span>_os<span> and ET</span>_rs<span> maps were evaluated for accuracy, using observed data from the Texas High Plains Evapotranspiration (TXHPET) network. Daily ET</span>_os<span>, ET</span>_rs<span> and the climatic data (air temperature, wind speed, and solar radiation) used for calculating ET</span>_ref<span> were extracted from the NOAA maps for TXHPET locations and compared against ground measurements on reference grass surfaces. NOAA ET</span>_ref<span>maps generally overestimated the TXHPET observations (1.4 and 2.2&nbsp;mm/day ET</span>_os<span> and ET</span>_rs<span>, respectively), which may be attributed to errors in the NLDAS modeled air temperature and wind speed, to which reference ET</span>_ref<span> is most sensitive. Therefore, a bias correction to NLDAS modeled air temperature and wind speed data, or adjustment to the resulting NOAA ET</span>_ref<span>, may be needed to improve the accuracy of NOAA ET</span>_ref<span> maps.</span></p> application/pdf 10.1111/1752-1688.12303 en Wiley Accuracy assessment of NOAA gridded daily reference evapotranspiration for the Texas High Plains article