Algorithm Descriptions
The Ocean Biology Processing Group (OBPG) produces and distributes a standard suite of ocean color products for all compatible sensors at Level-2 and Level-3, plus sea surface temperature (SST) products from MODIS and VIIRS. The OBPG also produces a suite of Level-3 evaluation products. The descriptions and references for these standard and evaluation products (provided below) are intended to satisfy the Algorithm Theoretical Basis Document (ATBD) requirement as defined by the NASA Earth Observing System Project Science Office.
Ocean Color Products
Standard
- Remote Sensing Reflectance (Rrs; sr-1)
- The at-surface spectral remote-sensing reflectances observed by the satellite instrument after atmospheric correction. The aerosol optical thickness and aerosol Ångström exponent products are also described.
- Chlorophyll a (chlor_a; mg m-3)
- The concentration of the photosynthetic pigment chlorophyll a
- Diffuse attenuation coefficient for downwelling irradiance at 490 nm (Kd_490; m-1)
- The diffuse attenuation coefficient for downwelling irradiance over the first optical attenuation layer
- Particulate Organic Carbon (POC; mg m-3)
- The concentration of particulate organic carbon
- Particulate Inorganic Carbon (PIC; mol m-3)
- The concentration of particulate inorganic carbon
- Photosynthetically Available Radiation (PAR; Einstein m-2 d-1)
- Daily mean photosynthetically available radiation at the ocean surface
- Instantaneous Photosynthetically Available Radiation (iPAR; Einstein m-2 s-1)
- PAR at the ocean surface at the time of the satellite observation
- Normalized Fluorescence Line Height (nFLH; mW cm-2 µm-1 sr-1)
- Relative measure of water-leaving radiance associated with chlorophyll fluorescence
Provisional
- Inherent Optical Properties from GIOP Algorithm (IOP, m-1)
- Spectral marine absorption and backscattering coefficients of water column constituents
- Inherent Optical Properties from GSM Algorithm (GSM; m-1)
- Spectral marine absorption and backscattering coefficients of water column constituents
- Inherent Optical Properties from QAA Algorithm (QAA; m-1)
- Spectral marine absorption and backscattering coefficients of water column constituents
- Euphotic Depth from Lee Algorigthm (ZLEE; m-1)
- Depth of the euphotic zone
- Land Reflectance from NDVI algorithm (LAND)
- Land reflectance generated from the Normalized Difference Vegetation Index (NDVI) algorithm
Special
Test
- Net Primary Productivity (NPP) from VGPM algorithm
- coming soon
- Net Primary Productivity (NPP) from VGPM/Eppley algorithm
- coming soon
- Calcite (ci2)
- Calcite concentration derived from particulate inorganic carbon
Sea Surface Temperature Products
Standard
- 11 µm Sea Surface Temperature (SST; °C)
- Sea surface temperature derived from long-wave (11-12 µm) thermal radiation
- 4 µm Sea Surface Temperature (SST4; °C)
- Sea surface temperature derived from short-wave (3-4 µm) thermal radiation
Developmental
- Aerosol correction for VIIRS SST
- Aerosol correction for sea surface temperature