What's in coastal water from its color (MERIS, coarse)
What it measures. Describes how seawater and the stuff in it absorbs and scatters light, broken into contributions from phytoplankton, dissolved organic matter and particles. These properties don't depend on lighting or viewing angle.
How it's made. Calculated from ENVISAT's MERIS ocean-color sensor by feeding its reflectance measurements into a model that separates out the different optical components.
How & where you'd use it. Used to classify water types, judge water clarity, study ocean biology and chemistry, and compare measurements across different satellites.
What's measured
Coverage & cadence
- Time span2002-03-21 → 2012-05-09
- Measured byENVISAT (MERIS)
- 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
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="MERIS_L2_RR_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. Official links
- Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. GET DATA
- View the version history of this product. VIEW RELATED INFORMATION
- NASA's Ocean Color Web - Data Distribution Site GET DATA
- ENVISAT Homepage VIEW RELATED INFORMATION
- MERIS Homepage VIEW RELATED INFORMATION
- Satellite data procesing can be difficult. We're here to help! Visit the Oceandata Help Hub to navigate learning content for accessing visualizing, and analyzing data products. VIEW RELATED INFORMATION
- Algorithm Theoretical Basis Document for Reduced Resolution (RR) Inherent Optical Properties (IOP) VIEW RELATED INFORMATION