Find research datasets worth reusing

VIIRS/NPP Actual and Potential Evapotranspiration Gap-Filled Yearly L4 Global 500m SIN Grid V002

The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Actual and Potential Evapotranspiration product is a gap-filled yearly composite dataset produced at 500 meter (m) pixel resolution. The VIIRS ET and PET algorithm is based on the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with VIIRS remotely sensed data products such as 8-day vegetation property dynamics and daily surface albedo.The VNP16A3GF will be generated at the end of each year when the entire yearly 8-day VNP15A2H is available. Hence, the gap-filled VNP16A3GF is the improved VNP16A2, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get VNP16A3GF in near-real time because it will be generated only at the end of a given year.Provided in the VNP16A3GF product are layers for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each VNP16A3GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year.Known Issues* Please refer to the [VIIRS Land Products website](https://viirsland.gsfc.nasa.gov/Products/NASA/ET_ESDR.html) and [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS) for information about VNP16A3GF known issues.

RM-OBS/PU Potential Evapotranspiration and Supporting Forcing L4 3-hourly 0.25x0.25 degree V002 (PET_PU_3H025) at GES DISC

This is version 2 of Princeton University MEaSUREs Potential Evapotranspiration (PET) dataset, which provides a set of estimates of PET based on near surface meteorology and surface radiation data derived from a combination of reanalysis, satellite and gridded gauge data. The rationale of the project is to reduce the error from the input meteorological forcing and provide a variety of widely-used PET methods for different research and application purposes.PET is estimated using three methods: Penman open-water method (Penman), Priestley-Taylor method (PT), Reference crop evapotranspiration using the UN Food and Agricultural Organization approach (FAO). The Penman equation assumes PET occurs from an open water surface and calculates PET based on observations of surface net radiation, near-surface air temperature, wind speed, and specific humidity (Shuttleworth, 1993). The PT equation calculates PET based on surface net radiation and near-surface air temperature and does not account for the aerodynamic component (Priestley and Taylor, 1972). The FAO equation is a specific application of the Penman-Monteith equation for crop and short-grass reference surfaces and is based on surface net radiation, near-surface air temperature, wind speed, and specific humidity (Allen, 1998). As a follow-on to PET_PU_3H025 Version 1, PET_PU_3H025 Version 2 seeks to continue to reduce the error from the input meteorological forcing and provide a variety of widely-used PET methods for different research and application purposes. The modifications include the addition of the FAO tall reference crop equation, an extension of the radiation data and temporal coverage, the usage of the GLASS satellite albedo to estimate upward short-wave radiation and the estimation of ground heat flux based on diurnal phase shift of net radiation.This second version of the dataset is estimated at a 3 hourly temporal resolution and 0.25x0.25 degrees spatial resolution globally, spanning the 33-year period 1984-2016. Datasets are stored as a 3-dimensional array with dimension 720 x 1440 x 8 for each day, in NetCDF-4 format.The DOI for version 1 of the data is: 10.5067/GPZDZYELYG1A.

VIIRS/JPSS1 Actual and Potential Evapotranspiration 8-Day L4 Global 500m SIN Grid V002

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Actual and Potential Evapotranspiration product is an 8-day composite dataset produced at 500 meter (m) pixel resolution. The VJ116A2 algorithm is based on the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with VIIRS remotely sensed data products such as 8-day vegetation property dynamics and daily surface albedo.Provided in the VJ116A2 product are layers for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each VJ116A2 granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the summation of 8-day total water loss within the composite period and the pixel values for the two Latent Heat layers (LE and PLE) are the average total energy over a unit area for a day during the composite period. Note that the last acquisition period of each year is a 5 or 6-day composite period, depending on the year.Known Issues* Please refer to the [VIIRS Land Products website](https://viirsland.gsfc.nasa.gov/Products/NASA/ET_ESDR.html) and [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS) for information about VJ116A2 known issues.

MODIS/Aqua Net Evapotranspiration Gap-Filled 8-Day L4 Global 500m SIN Grid V006

The MYD16A2GF Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the [MYD16A2GF Version 6.1](https://doi.org/10.5067/MODIS/MYD16A2GF.061) data product.The MYD16A2GF Version 6 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled 8-day composite dataset produced at 500 meter (m) pixel resolution. The improved algorithm is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MYD16A2GF will be generated at the end of each year when the entire yearly 8-day [MYD15A2H](https://doi.org/10.5067/MODIS/MYD15A2H.006) is available. Hence, the gap-filled MYD16A2GF is the improved MYD16, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MYD16A2GF in near-real time because it will be generated only at the end of a given year.Provided in the MYD16A2GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MYD16A2GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum of all eight days within the composite period, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all eight days within the composite period. The last acquisition period of each year is a 5- or 6-day composite period, depending on the year.Known Issues* Operational and uncertainty issues are provided on page 13 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Aqua&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

MODIS/Terra Net Evapotranspiration Yearly L4 Global 500m SIN Grid V006

The MOD16A3 Version 6 data product was decommissioned due to unexpected errors in the input data. Users are encouraged to use the [MOD16A3GF Version 6.1 data product](https://doi.org/10.5067/MODIS/MOD16A3GF.061).The MOD16A3 Version 6 Evapotranspiration/Latent Heat Flux product is a yearly composite dataset produced at 500 meter (m) pixel resolution. The algorithm is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover. Provided in the MOD16A3 product are layers for yearly Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MOD16A3 granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year. Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Terra&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

MODIS/Aqua Net Evapotranspiration 8-Day L4 Global 500m SIN Grid V006

The MYD16A2 Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the [MYD16A2 Version 6.1](https://doi.org/10.5067/MODIS/MYD16A2.061) data product.The MYD16A2 Version 6 Evapotranspiration/Latent Heat Flux product is an 8-day composite dataset produced at 500 meter (m) pixel resolution. The improved algorithm is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover.Provided in the MYD16A2 product are layers for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MYD16A2 granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum of all eight days within the composite period, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all eight days within the composite period. Note that the last acquisition period of each year is a 5 or 6-day composite period depending on the year.Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Aqua&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

MODIS/Terra Net Evapotranspiration Gap-Filled Yearly L4 Global 500m SIN Grid V006

The MOD16A3GF Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the [MOD16A3GF Version 6.1](https://doi.org/10.5067/MODIS/MOD16A3GF.061) data product.The MOD16A3GF Version 6 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled yearly composite dataset produced at 500 meter (m) pixel resolution. The algorithm used for the MOD16 data product collection is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MOD16A3GF will be generated at the end of each year when the entire yearly 8-day [MOD15A2H](https://doi.org/10.5067/MODIS/MOD15A2H.006) is available. Hence, the gap-filled MOD16A3GF is the improved MOD16, which has cleaned the poor-quality inputs from yearly Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MOD16A3GF in near-real time because it will be generated only at the end of a given year.Provided in the MOD16A3GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MOD16A3GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year.Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Terra&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

ECOSTRESS Gridded Evapotranspiration Instantaneous and Daytime L3 Global 70 m V002

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 in Figure 2 on the [ECOSTRESS website](https://ecostress.jpl.nasa.gov/science).The ECOSTRESS Gridded Evapotranspiration Instantaneous and Daytime L3 Global 70 m (ECO_L3G_JET) Version 2 data product provides instantaneous canopy transpiration, leaf surface evaporation, and soil moisture evaporation using the Priestley-Taylor formula. This data product is mosaicked from the L3 tiled JET (ECO_L3T_JET) product, projected to a globally snapped 0.0006° grid, and has a spatial resolution of 70 meters (m).The ECO_L3G_JET Version 2 data product contains 12 layers distributed in an HDF5 format file including ETdaily, ETinstUncertainty, PTJPLSMinst, STICinst, MOD16inst, BESSinst, STICcanopy, PTJPLSMcanopy, PTJPLSMinterception, PTJPLSMsoil, cloud mask, and water mask.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 TIR bands 2, 4, and 5 are being downloaded. The data products are as previously, except 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.* Solar Array Obstruction: Some ECOSTRESS scenes may be affected by solar array obstructions from the International Space Station (ISS), potentially impacting data quality of obstructed pixels. The 'FieldOfViewObstruction' metadata field is included in all Version 2 products to indicate possible obstructions: * Before October 24, 2024 (orbits prior to 35724): The field is present but was not populated and does not reliably identify affected scenes. * On or after October 24, 2024 (starting with orbit 35724): The field is populated and generally accurate, except for late December 2024, when a temporary processing error may have caused false positives. * A [list of scenes](https://lpdaac.usgs.gov/documents/2249/obst_all.sort.gz) confirmed to be affected by obstructions is available and is recommended for verifying historical data (before October 24, 2024) and scenes from late December 2024.* The ISS native pointing information is coarse relative to ECOSTRESS pixels, so ECOSTRESS geolocation is improved through image matching with a basemap. Metadata in the L1B_GEO file shows the success of this geolocation improvement, using categorizations "best", "good", "suspect", and "poor". We recommend that users use only "best" and "good" scenes for evaluations where geolocation is important (e.g., comparison to field sites). For some scenes, this metadata is not reflected in the higher-level products (e.g., land surface temperature, evapotranspiration, etc.). While this metadata is always available in the geolocation product, to save users additional download, we have produced a [summary text file](https://lpdaac.usgs.gov/documents/2253/qa_20250423-present.txt) that includes the geolocation quality flags for all scenes from launch to present. At a later date, all higher-level products will reflect the geolocation quality flag correctly (the field name is GeolocationAccuracyQA).Improvements/Changes from Previous Version* This product utilizes a modified version of the Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) model from the ECOSTRESS Evapotranspiration PT-JPL Daily L3

MODIS/Terra Net Evapotranspiration Gap-Filled 8-Day L4 Global 500m SIN Grid V006

The MOD16A2GF Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the [MOD16A2GF Version 6.1](https://doi.org/10.5067/MODIS/MOD16A2GF.061) data product.The MOD16A2GF Version 6 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled 8-day composite dataset produced at 500 meter (m) pixel resolution. The algorithm used for the MOD16 data product collection is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MOD16A2GF will be generated at the end of each year when the entire yearly 8-day [MOD15A2H](https://doi.org/10.5067/MODIS/MOD15A2H.006) is available. Hence, the gap-filled MOD16A2GF is the improved MOD16, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MOD16A2GF in near-real time because it will be generated only at the end of a given year.Provided in the MOD16A2GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MOD16A2GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum of all eight days within the composite period, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all eight days within the composite period. The last acquisition period of each year is a 5- or 6-day composite period, depending on the year.Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Terra&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

MODIS/Terra Net Evapotranspiration Gap-Filled 8-Day L4 Global 500m SIN Grid V061

The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) MOD16A2GF Version 6.1 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled 8-day composite dataset produced at 500 meter (m) pixel resolution. The algorithm used for the MOD16 data product collection is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with MODIS remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MOD16A2GF will be generated at the end of each year when the entire yearly 8-day [MOD15A2H](https://doi.org/10.5067/MODIS/MOD15A2H.061) is available. Hence, the gap-filled MOD16A2GF is the improved MOD16, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MOD16A2GF in near-real time because it will be generated only at the end of a given year.Provided in the MOD16A2GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MOD16A2GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum of all eight days within the composite period, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all eight days within the composite period. The last acquisition period of each year is a 5 or 6-day composite period, depending on the year.Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Terra&as=61).Improvements/Changes from Previous Versions* The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.* A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).* The product uses Climatology LAI/FPAR as back up to the operational LAI/FPAR.

MODIS/Aqua Net Evapotranspiration Gap-Filled Yearly L4 Global 500m SIN Grid V006

The MYD16A3GF Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the [MYD16A3GF Version 6.1](https://doi.org/10.5067/MODIS/MYD16A3GF.061) data product.The MYD16A3GF Version 6 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled yearly composite dataset produced at 500 meter (m) pixel resolution. The improved algorithm is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MYD16A3GF will be generated at the end of each year when the entire yearly 8-day [MYD15A2H](https://doi.org/10.5067/MODIS/MYD15A2H.006) is available. Hence, the gap-filled MYD16A3GF is the improved MYD16, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MYD16A3GF in near-real time because it will be generated only at the end of a given year.Provided in the MYD16A3GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MYD16A3GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year.Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Aqua&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

SRB/GEWEX evapotranspiration (Penman-Monteith) L4 3 hour 0.5 degree x 0.5 degree V1 (WC_PM_ET_050) at GES DISC

SRB/GEWEX evapotranspiration (Penman-Monteith) L4 3 hour 0.5 degree x 0.5 degree V1 is a global, 24-year (1984-2007), satellite-derived evapotranspiration over land data set. It is based on the Penman-Monteith model. Evapotranspiration provides the critical link between the water and energy cycles within the Earth system. Better representation of the spatial distribution and temporal development of surface evapotranspiration is needed not only to improve the description of water vapor exchanges for global water budget estimation but also to advance our understanding of the climate system.Input data sets include (1) vegetation index data, i.e., Leaf Area Index (LAI), derived from the Advanced Very High Resolution Radiometer (AVHRR) sensors onboard the NOAA-7, NOAA-9, NOAA-11, NOAA-14, and NOAA-16 satellites and the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the EOS-Terra and EOS-Aqua satellites; (2) meteorology data from the latest version of the Princeton University global forcing data sets and from the Variable Infiltration Capacity (VIC) land surface model output; and (3) radiative data from the NASA Global Energy and Water Exchanges (GEWEX) Surface Radiation Budget Project.

MODIS/Aqua Net Evapotranspiration Yearly L4 Global 500m SIN Grid V006

The MYD16A3 Version 6 data product was decommissioned on July 31, 2023. Users are encouraged to use the [MYD16A3GF Version 6.1](https://doi.org/10.5067/MODIS/MYD16A3GF.061) data product.The MYD16A3 Version 6 Evapotranspiration/Latent Heat Flux product is a yearly composite dataset produced at 500 meter (m) pixel resolution. The improved algorithm is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with Moderate Resolution Imaging Spectroradiometer (MODIS) remotely sensed data products such as vegetation property dynamics, albedo, and land cover. Provided in the MYD16A3 product are layers for yearly Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MYD16A3 granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year. Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Aqua&as=6).Improvements/Changes from Previous Versions* Spatial resolution of Version 6 products has increased to nominal 500 m from nominal 1,000 m in Version 5.* Version 5 data products were previously distributed by the Numerical Terradynamic Simulation Group at the University of Montana. The Version 6 products are a continuation of this project.

VIIRS/NPP Actual and Potential Evapotranspiration 8-Day L4 Global 500m SIN Grid V002

The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Actual and Potential Evapotranspiration (VNP16A2) data product is an 8-day composite dataset produced at 500 meter (m) pixel resolution. The VNP16A2 algorithm is based on the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with VIIRS remotely sensed data products such as 8-day vegetation property dynamics and daily surface albedo.Provided in the VNP16A2 product are layers for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each VNP16A2 granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the summation of 8-day total water loss within the composite period and the pixel values for the two Latent Heat layers (LE and PLE) are the average total energy over a unit area for a day during the composite period. Note that the last acquisition period of each year is a 5 or 6-day composite period, depending on the year.Known Issues* Please refer to the [VIIRS Land Products website](https://viirsland.gsfc.nasa.gov/Products/NASA/ET_ESDR.html) and [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS) for information about VNP16A2 known issues.

RM-OBS/PU Potential Evapotranspiration and Supporting Forcing L4 3-hourly 0.25x0.25 degree V001 (PET_PU_3H025) at GES DISC

The Princeton University MEaSUREs Potential Evapotranspiration (PET) dataset provides a set of estimates of PET based on near surface meteorology and surface radiation data derived from a combination of reanalysis, satellite and gridded gauge data. The rationale of the project is to reduce the error from the input meteorological forcing and provide a variety of widely-used PET methods for different research and application purposes.PET is estimated using three methods: Penman open-water method (Penman), Priestley-Taylor method (PT), Reference crop evapotranspiration using the UN Food and Agricultural Organization approach (FAO). The Penman equation assumes PET occurs from an open water surface and calculates PET based on observations of surface net radiation, near-surface air temperature, wind speed, and specific humidity (Shuttleworth, 1993). The PT equation calculates PET based on surface net radiation and near-surface air temperature and does not account for the aerodynamic component (Priestley and Taylor, 1972). The FAO equation is a specific application of the Penman-Monteith equation for crop and short-grass reference surfaces and is based on surface net radiation, near-surface air temperature, wind speed, and specific humidity (Allen, 1998). This first version of dataset is estimated at a 3 hourly temporal resolution and 0.25x0.25 degrees spatial resolution globally, spanning the 23-year period 1984-2006. Datasets are stored as a 3-dimensional array with dimension 720 x 1440 x 8 for each day, in NetCDF-4 format.

VIIRS/NPP Actual and Potential Evapotranspiration Gap-Filled 8-Day L4 Global 500m SIN Grid V002

The NASA/NOAA Suomi National Polar-orbiting Partnership (Suomi NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) Actual and Potential Evapotranspiration product is a gap-filled 8-day composite dataset produced at 500 meter (m) pixel resolution. The VIIRS ET and PET algorithm is based on the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with VIIRS remotely sensed data products such as 8-day vegetation property dynamics and daily surface albedo.The VNP16A2GF will be generated at the end of each year when the entire yearly 8-day VNP15A2H is available. Hence, the gap-filled VNP16A2GF is the improved VNP16A2, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get VNP16A2GF in near-real time because it will be generated only at the end of a given year.Provided in the VNP16A2GF product are layers for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each VNP16A2GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the summation of 8-day total water loss within the composite period and the pixel values for the two Latent Heat layers (LE and PLE) are the average total energy over a unit area for a day during the composite period. Note that the last acquisition period of each year is a 5 or 6-day composite period, depending on the year. Known Issues* Please refer to the [VIIRS Land Products website](https://viirsland.gsfc.nasa.gov/Products/NASA/ET_ESDR.html) and [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS) for information about VNP16A2GF known issues.

MODIS/Terra Net Evapotranspiration Gap-Filled Yearly L4 Global 500m SIN Grid V061

The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) MOD16A3GF Version 6.1 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled yearly composite dataset produced at 500 meter (m) pixel resolution. The algorithm used for the MOD16 data product collection is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with MODIS remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MODIS MOD16A3GF will be generated at the end of each year when the entire yearly 8-day [MOD15A2H](https://doi.org/10.5067/MODIS/MOD15A2H.061) is available. Hence, the gap-filled MOD16A3GF is the improved MOD16, which has cleaned the poor-quality inputs from yearly Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MOD16A3GF in near-real time because it will be generated only at the end of a given year.Provided in the MOD16A3GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MOD16A3GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year.Known Issues * Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Terra&as=61).Improvements/Changes from Previous Versions* The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.* A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).* The product uses Climatology LAI/FPAR as back up to the operational LAI/FPAR.

ECOSTRESS Tiled Evapotranspiration Instantaneous and Daytime L3 Global 70 m V002

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 in Figure 2 on the [ECOSTRESS website](https://ecostress.jpl.nasa.gov/science).The ECOSTRESS Tiled Evapotranspiration Instantaneous and Daytime L3 Global 70 m (ECO_L3T_JET) Version 2 data product provides instantaneous canopy transpiration, leaf surface evaporation, and soil moisture evaporation using the Priestley-Taylor formula. This data product is tiled using a modified version of the Military Grid Reference System ([MGRS](https://hls.gsfc.nasa.gov/products-description/tiling-system/)), which divides Universal Transverse Mercator (UTM) zones into square tiles that are 109.8 km by 109.8 km with a 70 meter (m) spatial resolution.The ECO_L3T_JET Version 2 data product is provided in Cloud Optimized GeoTIFF (COG) format, and each band is distributed as a separate COG. This product contains 12 layers including ETdaily, ETinstUncertainty, PTJPLSMinst, STICinst, MOD16inst, BESSinst, STICcanopy, PTJPLSMcanopy, PTJPLSMinterception, PTJPLSMsoil, cloud mask, and water mask.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 TIR bands 2, 4, and 5 are being downloaded. The data products are as previously, except 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.* Solar Array Obstruction: Some ECOSTRESS scenes may be affected by solar array obstructions from the International Space Station (ISS), potentially impacting data quality of obstructed pixels. The 'FieldOfViewObstruction' metadata field is included in all Version 2 products to indicate possible obstructions: * Before October 24, 2024 (orbits prior to 35724): The field is present but was not populated and does not reliably identify affected scenes. * On or after October 24, 2024 (starting with orbit 35724): The field is populated and generally accurate, except for late December 2024, when a temporary processing error may have caused false positives. * A [list of scenes](https://lpdaac.usgs.gov/documents/2249/obst_all.sort.gz) confirmed to be affected by obstructions is available and is recommended for verifying historical data (before October 24, 2024) and scenes from late December 2024.* The ISS native pointing information is coarse relative to ECOSTRESS pixels, so ECOSTRESS geolocation is improved through image matching with a basemap. Metadata in the L1B_GEO file shows the success of this geolocation improvement, using categorizations "best", "good", "suspect", and "poor". We recommend that users use only "best" and "good" scenes for evaluations where geolocation is important (e.g., comparison to field sites). For some scenes, this metadata is not reflected in the higher-level products (e.g., land surface temperature, evapotranspiration, etc.). While this metadata is always available in the geolocation product, to save users additional download, we have produced a [summary text file](https://lpdaac.usgs.gov/documents/2253/qa_20250423-present.txt) that includes the geolocation quality flags for all scenes from launch to present. At a later date, all higher-level products will reflect the geolocation quality flag correctly (the field name is Geolocation

MODIS/Aqua Net Evapotranspiration Gap-Filled Yearly L4 Global 500m SIN Grid V061

The Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) MYD16A3GF Version 6.1 Evapotranspiration/Latent Heat Flux (ET/LE) product is a year-end gap-filled yearly composite dataset produced at 500 meter (m) pixel resolution. The improved algorithm is based on the logic of the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with MODIS remotely sensed data products such as vegetation property dynamics, albedo, and land cover.The MYD16A3GF will be generated at the end of each year when the entire yearly 8-day [MYD15A2H](https://doi.org/10.5067/MODIS/MYD15A2H.061) is available. Hence, the gap-filled MYD16A3GF is the improved MYD16, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get MYD16A3GF in near-real time because it will be generated only at the end of a given year.Provided in the MYD16A3GF product are layers for composited ET, LE, Potential ET (PET), and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each MYD16A3GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year.Known Issues* Operational and uncertainty issues are provided under Section 3 in the User Guide.* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Aqua&as=61).Improvments/Changes from Previous Version* The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017.* A polarization correction has been applied to the L1B Reflective Solar Bands (RSB).* The product uses Climatology LAI/FPAR as back up to the operational LAI/FPAR.

VIIRS/JPSS1 Actual and Potential Evapotranspiration Gap-Filled Yearly L4 Global 500m SIN Grid V002

The NOAA-20 Visible Infrared Imaging Radiometer Suite (VIIRS) Actual and Potential Evapotranspiration product is a gap-filled yearly composite dataset produced at 500 meter (m) pixel resolution. The VIIRS ET and PET algorithm is based on the Penman-Monteith equation, which includes inputs of daily meteorological reanalysis data along with VIIRS remotely sensed data products such as 8-day vegetation property dynamics and daily surface albedo.The VJ116A3GF will be generated at the end of each year when the entire yearly 8-day VJ115A2H is available. Hence, the gap-filled VJ116A3GF is the improved VJ116A2, which has cleaned the poor-quality inputs from 8-day Leaf Area Index and Fraction of Photosynthetically Active Radiation (LAI/FPAR) based on the Quality Control (QC) label for every pixel. If any LAI/FPAR pixel did not meet the quality screening criteria, its value is determined through linear interpolation. However, users cannot get VJ116A3GF in near-real time because it will be generated only at the end of a given year.Provided in the VJ116A3GF product are layers for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control layer. Two low resolution browse images, ET and LE, are also available for each VJ116A3GF granule.The pixel values for the two Evapotranspiration layers (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat layers (LE and PLE) are the average of all days within the defined year.Known Issues* Please refer to the [VIIRS Land Products website](https://viirsland.gsfc.nasa.gov/Products/NASA/ET_ESDR.html) and [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=VIIRS) for information about VJ116A3GF known issues.