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Description

The Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS) NASA Level-2 (L2) Cloud Mask + Sounder is a new continuity product that leverages the synergy between the VIIRS instrument’s higher spatial resolution and the Cross-track Infrared Sounder (CrIS) instrument’s higher spectral resolution. This product is the result of a data fusion process between an imager (VIIRS) and a hyperspectral sounder (CrIS), which provides improved sensitivity in nighttime and polar regions utilizing additional information content from the sounder’s absorption channels (water vapor and carbon dioxide). This continuity product is designed to sustain the long-term records of both Moderate Resolution Imaging Spectroradiometer (MODIS) and VIIRS heritages but with cloud mask performance similar to the full-resolution MODIS cloud mask.

CLDMSK_L2_VIIRS-CRIS_SNPP is the shortname for the SNPP VIIRS version of this product that is derived from the MODIS-VIIRS cloud mask (MVCM) continuity algorithm, which itself is based on the MODIS (MOD35) algorithm. The MODIS (from Terra and Aqua missions) and VIIRS (from SNPP and Joint Polar Satellite System (JPSS) missions) data-derived cloud mask products use the MVCM algorithm. Implemented to consistently handle MODIS and VIIRS inputs, the v2.0 SNPP VIIRS Cloud Mask + Sounder collection products use calibration-adjusted NASA VIIRS L1B as inputs. The nominal spatial resolution of the SNPP VIIRS L2 Cloud mask is 750 meters at nadir. The v2.0 collection starts from March 1, 2012 (2012-061). The L2 netCDF product, acquired and processed every 6 minutes.

Consult the MODIS-VIIRS Cloud Mask Product User Guide for additional information regarding the transition from the MODIS-MOD35 to the MVCM algorithm, inputs to MVCM, output files, file naming conventions, quality flags, and validation. Users are also encouraged to consult the MOD35 Algorithm Theoretical Basis Document (ATBD) and the MODIS Atmosphere QA Plan for relevant information that are applicable to the NOAA-20 VIIRS Cloud Mask product.

Version Description

SUOMI-NPP VIIRS CrIS Version 2 Data

Product Summary

Platforms
Suomi-NPP
Instruments
VIIRS ,
CrIS
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2012-03-01 to Present
Data Partner
L1 and Atmosphere Archive and Distribution System,Biospheric Information Systems Branch, Hydrospheric and Biospheric Sciences Laboratory, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASA (NASA/GSFC/SED/ESD/H ,
Space Science and Engineering Center, University of Wisconsin, Madison (UWI-MAD/SSEC)
Concept ID
C3860042255-LAADS
Data State
ACTIVE
Number of Files/Granules
772064
Processing Level
2
Published
Science Keywords
Clouds ,
Cloud Frequency ,
Cloud Height ,
Infrared Radiance ,
REFLECTED INFRARED ,
Visible Radiance

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

VIIRS Atmosphere Science Team, S. S. E. C. (2026). VIIRS-CRIS/SNPP Cloud Mask + Sounder 6-Min L2 Swath 750m [Data set]. NASA Level 1 and Atmosphere Archive and Distribution System Distributed Active Archive Center. https://doi.org/10.5067/VIIRS/CLDMSK_L2_VIIRS-CRIS_SNPP.002 Date Accessed: 2026-05-04

File Naming Convention

Syntax: ESDT.AYYYYDDD.HHMM.CCC.YYYYDDDHHMMSS.Format
Example: CLDMSK_L2_VIIRS-CRIS_SNPP.A2019001.0000.002.2025219185953.nc


ESDT Earth Science Data Type or Shortname
A Stands for Acquisition
YYYYDDD Data acquisition year and Day-of-year
HHMM Acquisition Hour and Minute
CCC Version ID of the data collection
YYYYDDDHHMMSS Processing year, Day-of-year, UTC time (hour, minutes, seconds)
Format File format suffix, which in the above case represents netCDF4

Documents

USER'S GUIDE

ALGORITHM THEORETICAL BASIS DOCUMENT (ATBD)

Publications Citing This Dataset

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