What's in coastal water from its color (MERIS, full res)
What it measures. Per-pixel properties of coastal seawater that describe how the water and its contents absorb and scatter light, including signals from phytoplankton and dissolved organic matter, with uncertainty estimates.
How it's made. Retrieved from the color of the water as seen by the MERIS instrument on Europe's ENVISAT satellite, run through an optical model to separate out the different ingredients in the water.
How & where you'd use it. Supports judging water clarity, classifying water types, and biogeochemistry studies, and allows more reliable comparisons between different sensors than basic color products.
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 shap - 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_FRS_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 Full Resolution, Full Swath (FRS) Inherent Optical Properties (IOP) VIEW RELATED INFORMATION