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Full catalog/CLDMSK_L2_VIIRS_SNPP
CLDMSK_L2_VIIRS_SNPP·v1·dataset

Where clouds are blocking the view (VIIRS, Suomi-NPP)

VIIRS/Suomi-NPP Cloud Mask 6-Min Swath 750 m
atmosphere NASA LAADS Level 2 active NetCDF-4
In plain English

What it measures. For each spot the sensor sees, how confident the algorithm is that the view of Earth's surface is clear rather than blocked by cloud, plus an indication of shadows in the scene.

How it's made. Generated from the Suomi-NPP VIIRS instrument at 750-meter resolution by running a series of visible and infrared tests on the calibrated brightness it recorded.

How & where you'd use it. An essential filtering layer that other products use to throw out cloudy pixels. Most people rely on it indirectly when working with surface, temperature or color data that needs clear-sky views.

What's measured

ATMOSPHERE › CLOUDSATMOSPHERE › CLOUDS › CLOUD PROPERTIES › CLOUD FREQUENCYATMOSPHERE › CLOUDS › CLOUD PROPERTIES › CLOUD HEIGHTSPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › INFRARED RADIANCESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › REFLECTED INFRAREDSPECTRAL/ENGINEERING › VISIBLE WAVELENGTHS › VISIBLE RADIANCE

Coverage & cadence

  • Time span2012-03-01 → ongoing
  • Measured bySuomi-NPP (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/Suomi-NPP Cloud Mask 6-Min Swath 750m product is a Level-2 product generated at 750-m (at nadir) spatial resolutions. The algorithm employs a series of visible and infrared threshold and consistency tests to specify confidence that an unobstructed view of the Earth's surface has been observed. An indication of shadows affecting the scene is also provided. Radiometrically-accurate radiances are required, thus holes in the Cloud Mask will appear wherever the input radiances are incomplete or of poor quality assurance. For more information consult Product Page at: https://cimss.ssec.wisc.edu/MVCM/

Get the data

cldmsk_l2_viirs_snpp_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="CLDMSK_L2_VIIRS_SNPP",
    version="1",
    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.