OpenET DisALEXI Monthly Evapotranspiration v2.0

OpenET/DISALEXI/CONUS/GRIDMET/MONTHLY/v2_0
Dataset Availability
2008-01-01T00:00:00Z–2023-12-01T00:00:00Z
Dataset Provider
Earth Engine Snippet
ee.ImageCollection("OpenET/DISALEXI/CONUS/GRIDMET/MONTHLY/v2_0")
Tags
evapotranspiration gridmet-derived landsat-derived monthly openet water

Description

Atmosphere-Land Exchange Inverse / Disaggregation of the Atmosphere-Land Exchange Inverse (ALEXI/DisALEXI)

DisALEXI was recently ported to Google Earth Engine as part of the OpenET framework and the baseline ALEXI/DisALEXI model structure is described by Anderson et al. (2012, 2018). The ALEXI evapotranspiration (ET) model specifically uses time differential land surface temperature (LST) measurements from geostationary or moderate resolution polar orbiting platforms to generate regional ET maps. DisALEXI then disaggregates the regional ALEXI ET to finer scales using Landsat data (30 m; biweekly) to resolve individual farm fields and other landscape features. Additional information

Bands

Resolution
30 meters

Bands

Name Units Description
et mm

DisALEXI ET value

count count

Number of cloud free values

Image Properties

Image Properties

Name Type Description
build_date STRING

Date assets were built

cloud_cover_max DOUBLE

Maximum CLOUD_COVER_LAND percent value for Landsat images included in interpolation

collections STRING

List of Landsat collections for Landsat images included in the interpolation

core_version STRING

OpenET core library version

end_date STRING

End date of month

et_reference_band STRING

Band in et_reference_source that contains the daily reference ET data

et_reference_resample STRING

Spatial interpolation mode to resample daily reference ET data

et_reference_source STRING

Collection ID for the daily reference ET data

interp_days DOUBLE

Maximum number of days before and after each image date to include in interpolation

interp_method STRING

Method used to interpolate between Landsat model estimates

interp_source_count DOUBLE

Number of available images in the interpolation source image collection for the target month

mgrs_tile STRING

MGRS grid zone ID

model_name STRING

OpenET model name

model_version STRING

OpenET model version

scale_factor_count DOUBLE

Scaling factor that should be applied to the count band

scale_factor_et DOUBLE

Scaling factor that should be applied to the et band

start_date STRING

Start date of month

Terms of Use

Terms of Use

CC-BY-4.0

Citations

Citations:
  • Anderson, M., Gao, F., Knipper, K., Hain, C., Dulaney, W., Baldocchi, D ., Eichelmann, E., Hemes, K., Yang, Y., Medellin-Azuara, J. and Kustas, W., 2018. Field-scale assessment of land and water use change over the California Delta using remote sensing. Remote Sensing, 10(6), p.889. doi:10.3390/rs10060889

  • Anderson, M.C., Norman, J.M., Mecikalski, J.R., Otkin, J.A. and Kustas, W.P., 2007. A climatological study of evapotranspiration and moisture stress across the continental United States based on thermal remote sensing: 1. Model formulation. Journal of Geophysical Research: Atmospheres, 112(D10). doi:10.1029/2006JD007506

DOIs

Explore with Earth Engine

Code Editor (JavaScript)

var dataset = ee.ImageCollection('OpenET/DISALEXI/CONUS/GRIDMET/MONTHLY/v2_0')
  .filterDate('2020-01-01', '2021-01-01');

// Compute the annual evapotranspiration (ET) as the sum of the monthly ET
// images for the year.
var et = dataset.select('et').sum();

var visualization = {
  min: 0,
  max: 1400,
  palette: [
    '9e6212', 'ac7d1d', 'ba9829', 'c8b434', 'd6cf40', 'bed44b', '9fcb51',
    '80c256', '61b95c', '42b062', '45b677', '49bc8d', '4dc2a2', '51c8b8',
    '55cece', '4db4ba', '459aa7', '3d8094', '356681', '2d4c6e',
  ]
};

Map.setCenter(-100, 38, 5);

Map.addLayer(et, visualization, 'OpenET DisALEXI Annual ET');
Open in Code Editor