Full catalog/OCTS_L2_IOP
OCTS_L2_IOP·v2022.0·dataset

What's floating in coastal seawater, from ocean color (ADEOS)

ADEOS-I OCTS Level-2 Regional Inherent Optical Properties (IOP) Data, version 2022.0
ocean NASA OB_CLOUD Level 2 netCDF-4
In plain English

What it measures. How seawater and the particles in it absorb and scatter light, broken down into contributions from water itself, phytoplankton, and dissolved or detrital matter, plus uncertainty estimates for each.

How it's made. Calculated from ocean-color reflectance measured by the OCTS instrument on Japan's ADEOS-I satellite, using a standard model that turns color into these optical properties.

How & where you'd use it. Helps classify water types, judge water clarity, and study ocean biology and chemistry, and makes it easier to compare measurements from different satellites.

What's measured

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

Coverage & cadence

  • Time span1996-10-31 → 1997-06-30
  • Measured byADEOS-I (OCTS)
  • Processing levelLevel 2
  • 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 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) - l2_flags — Level-2 processing flags (bitmask; see per-variable attributes for flag_masks and flag_meanings). - 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

octs_l2_iop_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="OCTS_L2_IOP",
    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.