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Full catalog/ASCATB-L2-25km
ASCATB-L2-25km·vOperational/Near-Real-Time·dataset

Ocean surface wind speed and direction (MetOp-B, 25 km)

MetOp-B ASCAT Level 2 25.0km Ocean Surface Wind Vectors in Full Orbit Swath
ocean NASA POCLOUD Level 2 netCDF-4
In plain English

What it measures. The speed and direction of winds right at the ocean surface, reported as wind vectors along the satellite's orbit at about 25-km spacing.

How it's made. Retrieved from the ASCAT radar scatterometer on Europe's MetOp-B satellite, which senses surface roughness, and delivered as near-real-time orbit files about two hours after measurement.

How & where you'd use it. Feeds weather forecasting and storm tracking, and helps study ocean circulation and air-sea interaction.

What's measured

OCEANS › OCEAN WINDS › SURFACE WINDS › Ocean Surface Wind Vectors

Coverage & cadence

  • Time span2012-10-29 → ongoing
  • Measured byMETOP-B (ASCAT)
  • Processing levelLevel 2
  • Spatial extent-180, -89.6, 180, 89.6
  • FormatsnetCDF-4
  • StatusACTIVE

What you can do with it

  • Watch sea-surface temperature and marine heatwaves
  • Spot algal blooms and ocean-colour shifts
  • Support fisheries and coastal monitoring
Official description

This dataset contains operational near-real-time Level 2 ocean surface wind vector retrievals from the Advanced Scatterometer (ASCAT) on MetOp-B at 25 km sampling resolution (note: the effective resolution is 50 km). It is a product of the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) Ocean and Sea Ice Satellite Application Facility (OSI SAF) provided through the Royal Netherlands Meteorological Institute (KNMI). The wind vector retrievals are currently processed using the CMOD.n geophysical model function using a Hamming filter to spatially average the Sigma-0 data in the ASCAT L1B data. Each file is provided in netCDF version 3 format, and contains one full orbit derived from 3-minute orbit granules. Latency is approximately 2 hours from the latest measurement. The beginning of the orbit is defined by the first wind vector cell measurement within the first 3-minute orbit granule that starts north of the Equator in the ascending node. ASCAT is a C-band dual swath fan beam radar scatterometer providing two independent swaths of backscatter retrievals in sun-synchronous polar orbit aboard the MetOp-B platform. For more information on the MetOp-B mission, please visit: https://www.eumetsat.int/our-satellites/metop-series . For more timely announcements, users are encouraged to register with the KNMI scatterometer email list: scat@knmi.nl. Users are also highly advised to check the dataset user guide periodically for updates and new information on known problems and issues. All intellectual property rights of the OSI SAF products belong to EUMETSAT. The use of these products is granted to every interested user, free of charge. If you wish to use these products, EUMETSAT's copyright credit must be shown by displaying the words "copyright (year) EUMETSAT" on each of the products used.

Get the data

ascatb-l2-25km_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="ASCATB-L2-25km",
    version="Operational/Near-Real-Time",
    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 POCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.