Full catalog/VIIRSN_L3m_IOP_NRT
VIIRSN_L3m_IOP_NRT·v2022.0·dataset

What's floating in seawater, from ocean color (Suomi NPP, near-real-time)

Suomi-NPP VIIRS Level-3 Global Mapped Inherent Optical Properties (IOP) - Near Real-time (NRT) Data, version 2022.0
ocean NASA OB_CLOUD Level 3 active netCDF-4
In plain English

What it measures. Properties describing how seawater and whatever floats in it absorbs and scatters light, including total absorption and backscatter and contributions from phytoplankton and dissolved material. This is a near-real-time version with less-than-optimal calibration.

How it's made. Calculated from the VIIRS instrument's ocean-color reflectance on the Suomi-NPP satellite using a standard optical-properties model, then mapped globally.

How & where you'd use it. Supports classifying water types, judging water clarity, and biogeochemical studies, and allows more reliable comparisons across different satellites than basic color products.

What's measured

Oceans › Ocean Optics › AbsorptionOceans › Ocean Optics › ScatteringOceans › Ocean Optics › GelbstoffBiosphere › Ecosystems › Aquatic Ecosystems › Plankton › Phytoplankton

Coverage & cadence

  • Time span2012-01-02 → ongoing
  • Measured bySuomi-NPP (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 Inherent Optical Properties (IOP) suite provides per-pixel inherent optical properties - quantities that describe how seawater and its constituents absorb and scatter light, independent of illumination or viewing geometry. IOPs are retrieved from spectral Remote Sensing Reflectance (Rrs) using the default configuration of the Generalized Inherent Optical Properties (GIOP) model framework. These products support water-type classification, water-clarity assessment, biogeochemical studies, and forward/adjoint radiative-transfer applications, and they enable more robust cross-sensor comparisons than purely apparent (AOP) products. Geophysical variables in this suite include: - a – Total absorption coefficient (sum of pure water + phytoplankton + CDOM/detritus, m⁻¹) - bb – Total backscattering coefficient (m⁻¹) - aph_443 – Phytoplankton absorption coefficient at 443 nm (m⁻¹) - aph_unc_443 – Uncertainty in absorption due to phytoplankton at 443 nm (m⁻¹) - adg_443 – Combined CDOM + non-algal detritus absorption coefficient at 443nm; accompanied by adg_s (spectral slope, units nm⁻¹). - adg_unc_443 – Uncertainty in absorption due to gelbstoff and detrital material at 443 nm (m⁻¹). - bbp_443 – Particulate backscattering coefficient at 443nm (m⁻¹); include bbp_s (power-law slope, unitless) describing spectral shape. - bbp_unc_443 – Uncertainty in particulate backscattering at 443 nm (m⁻¹). - rrsdiff – Fractional mean Rrs difference.

Get the data

viirsn_l3m_iop_nrt_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="VIIRSN_L3m_IOP_NRT",
    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.