ERA5-Land energy-only potential evapotranspiration estimation

Knowledge graph centered on ERA5-Land energy-only potential evapotranspiration estimation with 47 nodes and 141 connections. Top connected: elevational gradients, snowpack persistence, groundwater storage dynamics, evapotranspiration, air temperature.

Method synopsis

Offline energy-only PET calculation using ERA5-Land reanalysis net radiation estimates, with optional snow albedo adjustment using MODIS observations.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Recent Upper Colorado River Streamflow Declines Driven by Loss of Spring Precipitation (2024), Geophysical Research Letters. Implementations in other papers (listed below) may differ.

1. Calculate potential evapotranspiration using PET-EO method
   Monthly PET was estimated using an offline 'energy-only' PET (PET-EO) method derived from ERA5-Land reanalysis net radiation estimates. The PET-EO method better matched in-situ measurements of non-water stressed ET than commonly used Penman-Monteith and Priestley-Taylor PET methods. While magnitudes of PET vary, the relationship between spring precipitation and PET is consistent across all methods examined.
   Quantities: Monthly PET estimates for each basinDuration: 1964-2022 periodConditions: Non-water stressed ET conditions
   Equipment: ERA5-Land reanalysis dataset
2. Adjust PET estimates for snow cover
   A second method (PET-EO-snow) adjusted the surface albedo for snow using MODIS observations of fractional snow-covered area, fSCA, on April 15 (midpoint of March-April-May) from 2001 to 2017. Snow covered grid-cells (fSCA = 1) have a surface albedo of 0.8, while snow-free grid-cells (fSCA = 0) have an albedo equal to the ERA5-Land modeled snow-free albedo value. For fSCA values between 0 and 1, albedo was calculated by combining the snow-covered and snow-free albedo in proportion to fSCA.
   Quantities: April 15 fSCA measurements from 2001-2017, albedo values 0.8 for snow-covered, variable for snow-freeDuration: 2001-2017 for MODIS dataConditions: April 15 midpoint measurements during dry versus wet springs
   Equipment: MODIS satellite observations, ERA5-Land albedo data

Typical Equipment

• ERA5-Land reanalysis dataset
• MODIS satellite observations

Output Measurements

• monthly PET estimates
• snow-adjusted PET estimates

Papers Using This Protocol (1)

Places Where Used