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Full catalog/VIIRSJ1_L2_OC
VIIRSJ1_L2_OC·v2022.0·dataset

Ocean color and tiny plant life (VIIRS, NOAA-20)

NOAA-20 VIIRS Level-2 Regional Ocean Color (OC) Data, version 2022.0
ocean NASA OB_CLOUD Level 2 active netCDF-4
In plain English

What it measures. A bundle of ocean-color measurements for stretches of sea, including how much sunlight bounces back off the water, how clear or murky it is, and estimates of chlorophyll (a stand-in for tiny floating plant life called phytoplankton), plus particles and carbon in the water.

How it's made. Derived from the VIIRS instrument on the NOAA-20 satellite, with the raw light measurements cleaned up to remove the haze of the atmosphere before the ocean values are calculated.

How & where you'd use it. Helps scientists watch phytoplankton blooms, gauge ocean productivity, follow water clarity, and study how carbon cycles through the upper ocean.

What's measured

Oceans › Ocean Optics › Ocean ColorOceans › Ocean Optics › ReflectanceAtmosphere › Aerosols › Aerosol Optical Depth/ThicknessAtmosphere › Aerosols › Aerosol Optical Depth/Thickness › Angstrom ExponentOceans › Ocean Optics › Chlorophyll › Chlorophyll ConcentrationOceans › Ocean Optics › Attenuation/TransmissionOceans › Ocean Chemistry › Organic CarbonOceans › Ocean Chemistry › Inorganic CarbonOceans › Ocean Optics › FluorescenceOceans › Ocean Optics › Photosynthetically Active Radiation

Coverage & cadence

  • Time span2017-11-29 → ongoing
  • Measured byNOAA-20 (VIIRS)
  • Processing levelLevel 2
  • Spatial extent-180, -90, 180, 90
  • 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

The Ocean Color (OC) data suite provides calibrated, atmospherically corrected ocean-optics measurements and derived biogeophysical products. This data suite includes the Apparent Optical Properties (AOP) and provides satellite-derived measures of the interaction between solar radiation and the upper ocean. AOPs are “apparent” because they depend not only on the inherent optical properties (IOPs) of seawater and its constituents but also on the ambient light field. These variables are critical for studying light penetration, primary productivity, and biogeochemical cycling. Geophysical variables in this suite include: - Kd_490 - Diffuse attenuation coefficient at 490 nm, KD2 algorithm (m⁻¹) - Rrs - Remote sensing reflectance (sr⁻¹) - angstrom - Aerosol Angstrom exponent, 443 to 865 nm - chlor_a - Chlorophyll Concentration, OCI Algorithm (mg m⁻³) - l2_flags - Level-2 Processing Flags - aot_868 - Aerosol optical thickness at 868 nm - par - Photosynthetically Available Radiation, R. Frouin (einstein m⁻² day^⁻¹) - pic - Calcite Concentration, Balch and Gordon (mol m⁻³) - poc - Particulate Organic Carbon, D. Stramski, 2007 (443/555 version) (mg m⁻³)

Get the data

viirsj1_l2_oc_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VIIRSJ1_L2_OC",
    version="2022.0",
    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 OB_CLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.