Potential and reference evapotranspiration (PET and RET, respectively) data are critical to quantitative hydrologic analyses. The USGS has partnered with all five State of Florida Water Management Districts to produce an annually updated product of daily, 2-km PET/RET data over the entire State from 1995 to the present (2012). The primary determinant of PET/RET is solar insolation, and the estimation of this variable is greatly facilitated by a remote sensing approach that captures the extreme variability in cloud cover over Florida. The USGS has partnered with the University of Alabama at Huntsville, which provides a calibrated solar insolation product based on the GOES satellite series. The USGS merges the solar insolation data with interpolated meteorological data from a dense network of weather stations for computation of PET and RET in a consistent statewide methodology.
Mean potential evapotranspiration (PET) over Florida during 2005 in units of millimeters per day.