Regional ocean data from the NOAA-20 satellite's VIIRS sensor provides per-pixel inherent optical properties (IOPs) in near real-time. The Ocean Biology DAAC produces these products using the best-available ancillary meteorological and ozone data for a snapshot within a single orbit. Retrieved IOPs describe how seawater absorbs and scatters light, supporting water-type classification and biogeochemical studies.
Use Cases
- Water-type classification based on retrieved inherent optical properties (IOPs) like absorption and backscattering coefficients.
- Water-clarity assessment based on the total absorption and backscattering coefficients (a and bb).
- Biogeochemical studies using phytoplankton and CDOM/detritus absorption coefficients (aph_445 and adg_445).
- Forward/adjoint radiative-transfer applications based on per-pixel IOPs that are independent of illumination geometry.
- Cross-sensor comparison of ocean color data using the more robust IOP framework compared to apparent optical properties.
Strengths
- Provides near real-time (NRT) data products, offering a snapshot of ocean conditions within a single orbit.
- Derives multiple geophysical variables, including total absorption (a), total backscattering (bb), and component-specific coefficients at 445 nm.
- Includes uncertainty estimates for key variables like aph_unc_445 and bbp_unc_445, supporting data quality assessment.
- Uses the Generalized Inherent Optical Properties (GIOP) model framework for retrieval, enabling more robust cross-sensor comparisons.
Limitations
- Description metadata is limited; actual data quality requires manual inspection after download.
- Row count is unknown, which may limit suitability assessment.
- The inputs and calibration used for NRT products are described as 'less than optimal' compared to standard products.
Provenance
- Source
- Ocean Biology DAAC (OB_CLOUD) via NASA's Earthdata platform, using data from the NOAA-20 satellite's VIIRS sensor.
- Collection Method
- Satellite remote sensing; IOPs are retrieved from spectral Remote Sensing Reflectance (Rrs) using the Generalized Inherent Optical Properties (GIOP) model framework.
- Freshness
- Near real-time (NRT); update frequency is not specified.
- Geography
- Regional coverage (specific regions not defined); data is per-pixel from satellite observations.