DOI: 10.5066/p1fwgebu
title: SSEBop Evapotranspiration from Landsat, 2000-2020 CONUS Monthly Actual ET (ETa)

description: USGS Evapotranspiration estimates provide useful information for a range of land use applications, from calculating a basin’s water budget to assessment of water consumption for crop yield and drought monitoring. This USGS data release is a result of using the OpenET Google Earth Engine (GEE) implementation of the USGS EROS Operational Simplified Surface Energy Balance (SSEBop) Evapotranspiration (ET) model (Version 0.2.6) to create monthly actual ET at 30-m spatial resolution, driven by land surface temperature from the Landsat thermal band. The results are Landsat-based monthly products generated from satellite imagery with <60% cloud cover and made available as a raster image collection from 2000-2020 for the conterminous United States (CONUS).
Raster data are organized into folders by Military Grid Reference System (MGRS) zones or tiles. Inside each folder exists two sets of files representing per month data products from 2000-01-01 to 2020-12-31 as follows:

[MGRSzone]_[YYYYMMDD]_[YYYYMMDD].tif files are monthly total model results. These are available in a Cloud Optimized GeoTIFF file format each containing two bands:

	
"et" band: Model actual ET (ETa) expressed as a monthly sum for the given month. Units: mm/month
"count" band: Total clear-sky satellite observations used within the model for the given month. Units: unitless


​[MGRSzone]_[YYYYMMDD]_[YYYYMMDD]_properties.json files include model properties information available in JSON file format for machine readability.

Users are advised to refer to the Supplemental Information in the metadata record for further information on this data.

These model ET products were developed using Landsat-based overpass ET fraction (ETf) images multiplied by a gridded daily grass reference ET (ETo) to estimate actual ET (ETa) on a daily basis. Time-integrated monthly products (total sum, mm/month) were derived with per-pixel linear interpolation and aggregation methodologies. For details about the algorithms and the data please refer to the data creation process and reference sections of this metadata. The complete data collection is approximately 3 TB in size, with individual rasters generally less than 1 GB each.
Access to Dataset


Data files for this data release are large and cannot be easily downloaded through standard protocols. Therefore, the data files are provided via a Globus Access Portal (linked under Related External Resources). Globus* is a fast, secure, and reliable way to move large data files and will automatically resume transfers when there are network disruptions. Learn more at https://www.globus.org/data-transfer. 

Note, in order to access the files, you will need to log in with an existing Globus account or create one and then perform a file transfer. If you are transferring the files to your local computer, you will also want to install and set up Globus Connect Personal to turn your local machine into an available Globus endpoint. There is no cost for a Globus account. Once Globus is set up, you are ready to access the raw product files.
Data access is available through a Globus access portal here: https://app.globus.org/file-manager?origin_id=02b2a4a7-6314-4b57-b857-249e9571c5c2&origin_path=%2F.

Non-USGS Source Code Disclaimer
(https://github.com/Open-ET/openet-ssebop)
This software is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The software has not received final approval by the U.S. Geological Survey (USGS). No warranty, expressed or implied, is made by the USGS or the U.S. Government as to the functionality of the software and related material nor shall the fact of release constitute any such warranty. The software is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the software.

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.