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Full catalog/OLCIS3A_L3m_ERR_CHL
OLCIS3A_L3m_ERR_CHL·v2022.0·dataset

Tiny ocean plants (chlorophyll) (Sentinel-3A)

Sentinel-3A OLCI Level-3 Global Mapped Earth-observation Reduced Resolution (ERR) Chlorophyll (CHL) Data, version 2022.0
ocean NASA OB_CLOUD Level 3 active netCDF-4
In plain English

What it measures. This maps the concentration of chlorophyll-a in surface ocean water worldwide, which stands in for how many tiny floating plants (phytoplankton) are present. More chlorophyll usually means more phytoplankton.

How it's made. It comes from the OLCI ocean-color instrument on Europe's Sentinel-3A satellite, processed into a gridded global product of chlorophyll concentration.

How & where you'd use it. Useful for tracking ocean ecosystems and fisheries, spotting unusual blooms, and studying long-term ocean health. Readings in murky coastal or inland waters carry more uncertainty.

What's measured

Oceans › Ocean Optics › Chlorophyll › Chlorophyll ConcentrationBIOSPHERE › VEGETATION › CHLOROPHYLLOCEANS › OCEAN CHEMISTRY › CHLOROPHYLLOCEANS › OCEAN CHEMISTRY › PIGMENTS › CHLOROPHYLLTERRESTRIAL HYDROSPHERE › WATER QUALITY/WATER CHEMISTRY › WATER CHARACTERISTICS › CHLOROPHYLL CONCENTRATIONSBIOSPHERE › ECOSYSTEMS › AQUATIC ECOSYSTEMS › PLANKTON › PHYTOPLANKTON

Coverage & cadence

  • Time span2016-04-05 → ongoing
  • Measured bySentinel-3A (OLCI)
  • Processing levelLevel 3
  • 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 Chlorophyll-a data suite provides global, gridded composites of surface chlorophyll-a concentration (a proxy for phytoplankton biomass). CHL supports time-series and climatologies, anomaly detection, ecosystem and fisheries applications, and teaching/training, and pairs well with AVW, PAR, Kd(490), SST, and winds for environmental context. Note: retrievals in optically complex coastal/inland waters may carry higher uncertainty—refer to the mission/algorithm documentation (e.g., OCx/OCI) for details. This activity was informed by the Satellite Needs Working Group (SNWG), an interagency effort of the U.S. Government dedicated to identifying and addressing Earth observation needs across U.S. civilian federal agencies. Geophysical variables in this suite include: - chlor_a — Chlorophyll-a concentration (mg m⁻³)

Get the data

olcis3a_l3m_err_chl_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="OLCIS3A_L3m_ERR_CHL",
    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.