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Full catalog/WATVP_D3_VIIRS_SNPP
WATVP_D3_VIIRS_SNPP·v1·dataset

Water vapor in the air column, daily (Suomi-NPP, 0.5 deg)

VIIRS/SNPP Water Vapor Level-3 daily 0.5 x 0.5 degree grid
atmosphere NASA LAADS Level 3 active netCDF-4
In plain English

What it measures. Daily global maps of the total amount of water vapor in the air column (how much moisture is overhead), at half-degree detail.

How it's made. Made by merging infrared and microwave water-vapor measurements from the VIIRS, CrIS, and ATMS instruments on the Suomi-NPP satellite, then averaging them into daily grid cells.

How & where you'd use it. Supports weather analysis and forecasting and continues a long record of global moisture monitoring begun with the MODIS instruments.

What's measured

ATMOSPHERE › ATMOSPHERIC WATER VAPORATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR INDICATORSATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR INDICATORS › HUMIDITYATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR INDICATORS › TOTAL PRECIPITABLE WATERATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR INDICATORS › WATER VAPORATMOSPHERE › ATMOSPHERIC WATER VAPOR › WATER VAPOR PROFILES

Coverage & cadence

  • Time span2012-05-01 → ongoing
  • Measured bySuomi-NPP (VIIRS)
  • Processing levelLevel 3
  • Spatial extent-180, -90, 180, 90
  • FormatsnetCDF-4
  • StatusCOMPLETE

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/SNPP Water Vapor Level-3 daily 0.5 x 0.5 degree grid Product provide total column water vapor (TPW) properties from merged VIIRS infrared measurements and Cross-track Infrared Sounder (CrIS) plus Advanced Technology Microwave Sounder (ATMS) water vapor soundings to continue the depiction of global moisture at a higher spatial resolution started with MODIS on the Terra and Aqua platforms. Level-3 global 0.5 degree by 0.5 degree spatial resolution daily mean data products (called WATVP_D3_VIIRS_SNPP) is derived by using a gridding software (called Yori) developed at the University of Wisconsin, Madison, Space Science and Engineering Center (Veglio et al., 2018), and implemented by the NASA VIIRS Atmosphere Science Investigator-led Processing System (SIPS). The Yori has been adapted for the VIIRS TPW products and is processed using the VIIRS Level-2 Water Vapor products (WATVP_L2_VIIRS_SNPP) separated by day and night. The mean and the standard deviation of each Level-2 water vapor product are calculated for each grid cell. The sum, the square of the sum of each product, and the number of pixels in the cells are also stored in the Level-3 (daily) output files for further aggregation purposes.

Get the data

watvp_d3_viirs_snpp_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="WATVP_D3_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.