Assessing integrity of weather data for reference evapotranspiration estimation

Procedures and guidelines are recommended for assessing integrity, quality, and reasonableness of measured weather data and equipment calibration for automated and electronic agricultural weather stations. The procedures include calculation of hourly and 24-h clear sky envelopes for solar radiation, validation of net radiation measurements using calculation equations, and evaluation of expected trends and relationships between air vapor content and air temperature. The procedures for creating clear sky solar radiation envelopes include equations to account for the effects of atmospheric water vapor content and sun angle. Procedures for adjusting air temperature and air vapor content data are introduced to compensate for the aridity of the weather station environment. All of the guidelines are simple and straightforward, and can serve as preliminary ''filters'' by which to scrutinize weather measurements and as near real-time data flagging procedures for agricultural weather networks.