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Full catalog/SeaWiFS_L3b_PAR
SeaWiFS_L3b_PAR·v2022.0·dataset

Sunlight reaching the sea for photosynthesis (SeaWiFS)

OrbView-2 SeaWiFS Level-3 Global Binned Photosynthetically Available Radiation (PAR) Data, version 2022.0
ocean NASA OB_CLOUD Level 3 netCDF-4
In plain English

What it measures. How much sunlight in the range plants can use for photosynthesis reaches the ocean surface, expressed as the daily amount of usable light energy arriving on each patch of sea.

How it's made. Estimated from ocean-color observations by the SeaWiFS instrument on the OrbView-2 satellite and binned into global maps.

How & where you'd use it. Used to estimate how much the ocean's tiny plants grow (marine primary production), interpret phytoplankton blooms, and feed ecosystem models.

What's measured

Oceans › Ocean Optics › Photosynthetically Active Radiation

Coverage & cadence

  • Time span1997-09-04 → 2010-12-11
  • Measured byOrbView-2 (SeaWiFS)
  • Processing levelLevel 3
  • Spatial extent-180, -90, 180, 90
  • FormatsnetCDF-4
  • StatusCOMPLETE

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 Photosynthetically Available Radiation (PAR) data suite provides satellite-based estimates of the downwelling solar radiation in the 400–700 nm range that is available for photosynthesis at the ocean surface. These products quantify the daily or instantaneous amount of usable light energy, expressed in moles of photons m⁻² (commonly noted as “Einstein m⁻²”), and are widely used to estimate marine primary production, interpret phytoplankton bloom dynamics, provide context for optical and biogeochemical measurements,and support ecosystem models and education on light–biology interactions. Geophysical variables in this suite include: - par — Daily photosynthetically available radiation (mol photons m⁻² d⁻¹)

Get the data

seawifs_l3b_par_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SeaWiFS_L3b_PAR",
    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.