Where there's snow, daily (VIIRS, NOAA-21, 375 m) — VJ210A1

In plain English

What it measures. Daily maps showing where snow is on the ground around the world, at a fine 375-meter resolution.

How it's made. Created from the VIIRS instrument on the NOAA-21 (JPSS-2) satellite, which spots snow using a brightness index plus checks to weed out false detections, then stitches the views into a daily gridded map.

How & where you'd use it. Helps with tracking seasonal snow cover for water-supply forecasting, flood risk, and climate monitoring, especially in mountains and northern regions.

What's measured

CRYOSPHERE › SNOW/ICE › SNOW COVER

Coverage & cadence

Time span2023-02-10 → ongoing
Measured byJPSS-2 (VIIRS) · NOAA-21 (VIIRS)
Processing levelLevel 3
Spatial extent-180, -90, 180, 90
FormatsHDF-EOS5
StatusACTIVE

What you can do with it

Measure sea ice, snow cover and glaciers
Watch ice-sheet elevation change
Track freeze/thaw and permafrost

Official description

This data set contains daily snow cover derived from radiance data acquired by the Visible Infrared Imaging Radiometer Suite (VIIRS) on board the Joint Polar Satellite System's second satellite (JPSS-2). The data is a gridded composite, generated from 6 minute swaths, and projected to a 375 m Sinusoidal grid. Snow cover is identified using the Normalized Difference Snow Index (NDSI) and a series of screens designed to alleviate errors and flag uncertain snow cover detections.

Get the data

vj210a1_access.py

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

results = earthaccess.search_data(
    short_name="VJ210A1",
    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 NSIDC_CPRD

Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.

What's measured

Coverage & cadence

What you can do with it

Get the data

Official links