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Full catalog/VJ116A2
VJ116A2·v002·dataset

How much water plants use (NOAA-20, 8-day, 500 m)

VIIRS/JPSS1 Actual and Potential Evapotranspiration 8-Day L4 Global 500m SIN Grid V002
atmosphere NASA LPCLOUD Level 4 active HDF-EOS5
In plain English

What it measures. Estimates of how much water the land loses to the air through evaporation and plant transpiration for each 500-meter patch, including both the actual water lost and the maximum that could be lost under ideal conditions, summed over 8-day periods.

How it's made. Calculated by the VIIRS instrument on the NOAA-20 satellite using a standard water-and-energy equation that combines weather data with satellite measurements of vegetation and surface brightness.

How & where you'd use it. Useful for managing irrigation and water supplies, monitoring drought, and studying how land and atmosphere exchange water and energy.

What's measured

ATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROCESSES › EVAPOTRANSPIRATIONATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROCESSES › EVAPORATIONATMOSPHERE › PRECIPITATION › PRECIPITATION PROFILES › LATENT HEAT FLUX

Coverage & cadence

  • Time span2025-01-01 → ongoing
  • Measured byNOAA-20 (VIIRS)
  • Processing levelLevel 4
  • Spatial extent-180, -90, 180, 90
  • FormatsHDF-EOS5
  • StatusACTIVE

What you can do with it

  • Map air pollutants — NO₂, aerosols, ozone
  • Track greenhouse gases and Earth's energy budget
  • Feed weather and air-quality analysis
Official description

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.

Get the data

vj116a2_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ116A2",
    version="002",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from LPCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.