Earth Data School
About
Full catalog/VJ116A3GF
VJ116A3GF·v002·dataset

How much water plants use, gap-filled yearly (NOAA-20, 500 m)

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

What it measures. Yearly estimates of how much water plants and land actually use (evapotranspiration) and how much they could use under ideal conditions (potential evapotranspiration), at 500-meter detail, with gaps filled in.

How it's made. Calculated from the VIIRS sensor on the NOAA-20 satellite using a standard water-and-energy equation, combining daily weather data with satellite measurements of vegetation and surface brightness, then cleaned and gap-filled at year's end.

How & where you'd use it. Useful for tracking water use by ecosystems and crops, monitoring drought, and managing water resources, though because it's compiled yearly it isn't available in near real-time.

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 span2018-01-01 → 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 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 variables for composited Evapotranspiration (ET), Latent Heat Flux (LE), Potential ET (PET) and Potential LE (PLE) along with a quality control variable. Two low resolution browse images, ET and LE, are also available for each VJ116A3GF granule. The pixel values for the two Evapotranspiration variables (ET and PET) are the sum for all days within the defined year, and the pixel values for the two Latent Heat variables (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.

Get the data

vj116a3gf_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VJ116A3GF",
    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.