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Full catalog/AERDT_L2_VIIRS_NOAA20
AERDT_L2_VIIRS_NOAA20·v2·dataset

Haze, dust and smoke over dark areas (VIIRS, NOAA-20)

VIIRS/NOAA20 Dark Target Aerosol 6-Min L2 Swath 6 km
atmosphere NASA LAADS Level 2 active netCDF-4
In plain English

What it measures. This measures how much haze, dust and smoke is in the air over darker land and ocean surfaces, reporting the thickness of the airborne particle layer and, over the ocean, clues about particle size.

How it's made. Derived from the VIIRS sensor on the NOAA-20 satellite using the same long-standing 'Dark Target' method first developed for MODIS, delivered as 6-minute strips along the orbit.

How & where you'd use it. Used to monitor air quality, smoke and dust events, and to study how airborne particles affect climate, weather and health.

What's measured

ATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESSATMOSPHERE › AEROSOLS › AEROSOL OPTICAL DEPTH/THICKNESS › ANGSTROM EXPONENTATMOSPHERE › AEROSOLSATMOSPHERE › AEROSOLS › AEROSOL PARTICLE PROPERTIES

Coverage & cadence

  • Time span2018-02-17 → ongoing
  • Measured byNOAA-20 (VIIRS)
  • Processing levelLevel 2
  • Spatial extent-180, -90, 180, 90
  • FormatsnetCDF-4
  • 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 VIIRS/NOAA20 Dark Target Aerosol L2 6-Min Swath 6 km product provides satellite-derived measurements of Aerosol Optical Thickness (AOT) and their properties over land and ocean, and spectral AOT and their size parameters over oceans every 6 minutes, globally. The NOAA-20 - formerly the Joint Polar Satellite System-1 (JPSS-1) - Visible Infrared Imaging Radiometer Suite (VIIRS) incarnation of the dark target (DT) aerosol product is based on the same DT algorithm that was developed and used to derive products from the Terra and Aqua mission's MODIS instruments. Two separate and distinct DT algorithms exist. One helps retrieve aerosol information over ocean (dark in visible and longer wavelengths), while the second aids retrievals over vegetated/dark-soiled land (dark in the visible). This orbit-level product (Short-name: AERDT_L2_VIIRS_NOAA20) has an at-nadir resolution of 6 km x 6 km, and progressively increases away from nadir given the sensor's scanning geometry and Earth's curvature. Viewed differently, this product's resolution accommodates 8 x 8 native VIIRS moderate-resolution (M-band) pixels that nominally have ~750 m horizontal pixel size. Hence, the Level-2 Dark Target Aerosol Optical Thickness data product incorporates 64 (750 m) pixels over a 6-minute acquisition. This Version-2 set of products is the first collection of the Level-2 Dark Target Aerosol derived from the NOAA-20 VIIRS source. Hence, it bears outlining the differences between the products derived from NOAA-20 VIIRS as against the Suomi National Polar-orbiting Partnership (SNPP) VIIRS. For more information consult LAADS [product description page](https://ladsweb.modaps.eosdis.nasa.gov/missions-and-measurements/products/AERDT_L2_VIIRS_NOAA20) or [Dark Target aerosol team page](https://darktarget.gsfc.nasa.gov/).

Get the data

aerdt_l2_viirs_noaa20_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="AERDT_L2_VIIRS_NOAA20",
    version="2",
    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 LAADS
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.