ECO_L4G_ESI v002

ECOSTRESS Gridded Evaporative Stress Index PT-JPL Instantaneous L4 Global 70 m

PI: Simon Hook, Gregory Halverson


The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission measures the temperature of plants to better understand how much water plants need and how they respond to stress. ECOSTRESS is attached to the International Space Station (ISS) and collects data globally between 52° N and 52° S latitudes. A map of the acquisition coverage can be found on the ECOSTRESS website.

The ECOSTRESS Gridded Evaporative Stress Index PT-JPL Instantaneous L4 Global 70 m (ECO_L4G_ESI) Version 2 data product uses the Priestley-Taylor Jet Propulsion Laboratory Soil Moisture (PT-JPL-SM) model to generate estimates of both actual and potential instantaneous evapotranspiration (ET). The potential evapotranspiration (PET) estimate represents the maximum expected ET if there were no water stress to plants on the ground. The ratio of the actual ET estimate to the PET estimate forms an index representing the water stress of plants.

The ECO_L4G_ESI Version 2 data product is available globally and is projected to a globally snapped 0.0006° grid with a 70 meter spatial resolution and is distributed in HDF5. Each granule contains layers of Evaporative Stress Index (ESI), PET, cloud mask, and water mask. A low-resolution browse is also available showing daily ESI as a stretched image with a color ramp in JPEG format.

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Collection and Granule


Characteristic Description
File Size~4 MB
Temporal ResolutionVaries
Temporal Extent2018-07-09 to Present
Spatial ExtentGlobal (+/- 52 degrees latitude)
Coordinate SystemGeographic Latitude and Longitude
DatumWorld Geodetic System (WGS84)
File FormatHDF5
Geographic Dimensions400 km x 400 km


Characteristic Description
Number of Science Dataset (SDS) Layers4
Columns/Rows5400 x 5632
Pixel Size70 m

Layers / Variables

SDS Name Description Units Data Type Fill Value No Data Value Valid Range Scale Factor
ESI Evaporative Stress Index Ratio 32-bit floating point NaN N/A 0 to 1 N/A
PET Potential Evapotranspiration W/m² 32-bit floating point NaN N/A N/A N/A
cloud Cloud Mask N/A 32-bit floating point 255 N/A 0, 1 N/A
water Water Mask N/A 32-bit floating point 255 N/A 0, 1 N/A

Cloud Mask Values

Class Description
0 Clear
1 Cloudy

Water Mask Values

Class Description
0 Land
1 Water

Product Quality

Quality information for the ECO_L4G_ESI Version 2 data product is described in Section 5 of the ATBD.

Known Issues

  • Data acquisition gap: ECOSTRESS was launched on June 29, 2018, and moved to autonomous science operations on August 20, 2018, following a successful in-orbit checkout period. On September 29, 2018, ECOSTRESS experienced an anomaly with its primary mass storage unit (MSU). ECOSTRESS has a primary and secondary MSU (A and B). On December 5, 2018, the instrument was switched to the secondary MSU, and science operations resumed. On March 14, 2019, the secondary MSU experienced a similar anomaly, temporarily halting science acquisitions. On May 15, 2019, a new data acquisition approach was implemented, and science acquisitions resumed. To optimize the new acquisition approach, only Thermal Infrared (TIR) bands 2, 4, and 5 are being downloaded. The data products are the same as before, but the bands not downloaded contain fill values (L1 radiance and L2 emissivity). This approach was implemented from May 15, 2019, through April 28, 2023.

  • Data acquisition gap: From February 8 to February 16, 2020, an ECOSTRESS instrument issue resulted in a data anomaly that created striping in band 4 (10.5 micron). These data products have been reprocessed and are available for download. No ECOSTRESS data were acquired on February 17, 2020, due to the instrument being in SAFEHOLD. Data acquired following the anomaly have not been affected.

  • Data acquisition: ECOSTRESS has now successfully returned to 5-band mode after being in 3-band mode since 2019. This feature was successfully enabled following a Data Processing Unit firmware update (version 4.1) to the payload on April 28, 2023. To better balance contiguous science data scene variables, 3-band collection is currently being interleaved with 5-band acquisitions over the orbital day/night periods.

About the image

ECOSTRESS evaporative stress index (ESI) layer from ECO_L4G_ESI product, acquired over New Mexico, United States, on October 20, 2023.

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User Guide
Algorithm Theoretical Basis Document (ATBD)

Using the Data

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