Accuracy assessment of NOAA gridded daily reference evapotranspiration for the Texas High Plains

Journal of the American Water Resources Association
By: , and 

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Abstract

The National Oceanic and Atmospheric Administration (NOAA) provides daily reference evapotranspiration (ETref) 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 ETref, which is essential for regional scale water resources management. Data used in the development of NOAA daily ETref maps are derived from observations over surfaces that are different from short (grass — ETos) or tall (alfalfa — ETrs) reference crops, often in nonagricultural settings, which carries an unknown discrepancy between assumed and actual conditions. In this study, NOAA daily ETos and ETrs maps were evaluated for accuracy, using observed data from the Texas High Plains Evapotranspiration (TXHPET) network. Daily ETos, ETrs and the climatic data (air temperature, wind speed, and solar radiation) used for calculating ETref were extracted from the NOAA maps for TXHPET locations and compared against ground measurements on reference grass surfaces. NOAA ETrefmaps generally overestimated the TXHPET observations (1.4 and 2.2 mm/day ETos and ETrs, respectively), which may be attributed to errors in the NLDAS modeled air temperature and wind speed, to which reference ETref is most sensitive. Therefore, a bias correction to NLDAS modeled air temperature and wind speed data, or adjustment to the resulting NOAA ETref, may be needed to improve the accuracy of NOAA ETref maps.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Accuracy assessment of NOAA gridded daily reference evapotranspiration for the Texas High Plains
Series title Journal of the American Water Resources Association
DOI 10.1111/1752-1688.12303
Volume 51
Issue 5
Year Published 2015
Language English
Publisher Wiley
Contributing office(s) Earth Resources Observation and Science (EROS) Center
Description 10 p.
First page 1262
Last page 1271
Country United States
State Texas