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Full catalog/VIIRSJ2_L3m_POC_NRT
VIIRSJ2_L3m_POC_NRT·v2025.0·dataset

Carbon in tiny ocean particles (NOAA-21, near-real-time)

NOAA-21 VIIRS Level-3 Global Mapped Particulate Organic Carbon (POC) - Near Real-time (NRT) Data, version 2025.0
ocean NASA OB_CLOUD Level 3 active netCDF-4
In plain English

What it measures. The concentration of carbon held in tiny organic particles floating in surface seawater, mapped globally. Being a near-real-time product, its calibration is rougher than the final version.

How it's made. Derived from ocean-color reflectance measured by the VIIRS instrument on the NOAA-21 satellite, quickly processed into a global gridded map.

How & where you'd use it. Used to estimate how much carbon is stored in surface ocean particles and to support studies of ocean carbon cycling and transport to deeper water.

What's measured

Oceans › Ocean Chemistry › Organic CarbonOCEANS › OCEAN CHEMISTRY › CARBONOCEANS › OCEAN OPTICS

Coverage & cadence

  • Time span2022-11-10 → ongoing
  • Measured byNOAA-21 (VIIRS)
  • 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 Ocean Biology DAAC produces near real-time (NRT) products using the best-available combination of ancillary data from meteorological and ozone data. As such, the inputs and the calibration used are less than optimal. Near real-time products provide a snapshot of the data during a short time period within a single orbit. The Particulate Organic Carbon (POC) data suite includes product of particulate organic carbon concentration from ocean-color reflectance. POC is widely used to quantify surface carbon stocks, support biogeochemical and export-flux studies, and provide ecological context alongside chlor_a, bbp, Kd_490, and SST. Geophysical variables in this suite include: - poc - Particulate Organic Carbon (mg C m⁻³), D. Stramski, 2007 (443/555 version)

Get the data

viirsj2_l3m_poc_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VIIRSJ2_L3m_POC_NRT",
    version="2025.0",
    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.