Background
Ocean color products produced from the Ocean and Land Colour Instrument (OLCI) on Sentinel-3 A/3B are available through the Ocean Biology Distributed Active Archive Center (OB.DAAC). They include Level 2 (300 m resolution) and Level 3 (global 1.2 km resolution) data products, as derived using standard NASA ocean color algorithms and the NASA vicarious calibration approach. The goal is to minimize bias between OLCI products and the standard ocean color time-series derived from the Sea-viewing Wide Field of View Sensor (SeaWIFS), the Moderate Resolution Imaging Spectroradiometer (MODIS), and the Visible Infrared Imaging Radiometer Suite (VIIRS) instruments.
The datasets were reprocessed in 2022 to further improve the quality and consistency of the OLCI products (additional information is available on Sentinel-3A and Sentinel-3B reprocessing). The Level 2 and Level 3 processing capability is also distributed as open source software through the Sea, earth, atmosphere Data Analysis System (SeaDAS) software package.
These products are used by agencies including NASA, the National Oceanic and Atmospheric Administration (NOAA), the Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), and U.S. Army Corps of Engineers (USACE), as well as various state agencies. The data are used for applications such as assessment of water quality, detection of harmful algal blooms in coastal and inland waters (e.g., Cyanobacteria Assessment Network (CyAN)), management of fisheries and aquaculture health, and detection of macroalgae for its impact on coastal tourism (e.g., Sargassum Watch).
Status: Available Now
The solution has been fully implemented with data available through OB.DAAC and EarthDataCloud. Forward stream production continues as new Level 1B data is acquired, with periodic reprocessing as needed to maintain data quality. The next reprocessing and update to forward stream is in development to incorporate the latest (recalibrated) Level 1B version 4 updates from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).
Solution Characteristics
| Products | Ocean Color Data (OC) | Inherent Optical Properties (IOP) | Chlorophyll (CHL) | Diffuse Attenuation Coefficient for Downwelling Irradiance (KD) | Remote Sensing Reflectance |
|---|---|---|---|---|---|
| Number of available products | 6 | 14 | 8 | 8 | 8 |
| Platform | Sentinel-3A/B | Sentinel-3A/B | Sentinel-3A/B | Sentinel-3A/B | Sentinel-3A/B |
| Instrument | OLCI | OLCI | OLCI | OLCI | OLCI |
| Sensor Type | Visible/Near-Infrared Imaging Spectrometer | Visible/Near-Infrared Imaging Spectrometer | Visible/Near-Infrared Imaging Spectrometer | Visible/Near-Infrared Imaging Spectrometer | Visible/Near-Infrared Imaging Spectrometer |
| Processing Level | 2 | 2 and 3 | 3 | 3 | 3 |
| Temporal Coverage | Sentinel-3A: April 25, 2016 to Present Sentinel-3B: April 25, 2018 to Present | Sentinel-3A: April 25, 2016 to Present Sentinel-3B: April 25, 2018 to Present | Sentinel-3A: April 25, 2016 to Present Sentinel-3B: April 25, 2018 to Present | Sentinel-3A: April 25, 2016 to Present Sentinel-3B: April 25, 2018 to Present | Sentinel-3A: April 25, 2016 to Present Sentinel-3B: April 25, 2018 to Present |
| Revisit Time | Less than 2 days Note: Sentinel-3A/B combined for OLCI | Less than 2 days Note: Sentinel-3A/B combined for OLCI | Less than 2 days Note: Sentinel-3A/B combined for OLCI | Less than 2 days Note: Sentinel-3A/B combined for OLCI | Less than 2 days Note: Sentinel-3A/B combined for OLCI |
| Latency | Near real-time (NRT)*: 1-4 days Final: Approximately 45 days | NRT*: 1-4 days Final: Approximately 45 days | NRT*: 1-4 days Final: Approximately 45 days | NRT*: 1-4 days Final: Approximately 45 days | NRT*: 1-4 days Final: Approximately 45 days |
| Spatial Coverage | Global | Global | Global | Global | Global |
| Spatial Resolution | 300 m and 1200 m (original swath) | L2: 300 m and 1200 m (original swath) L3: 4.6 km (binned) or 4 km and 9 km (mapped) | 4.6 km (binned) or 4 km and 9 km (mapped) | 4.6 km (binned) or 4 km and 9 km (mapped) | 4.6 km (binned) or 4 km and 9 km (mapped) |
| Data Format | NetCDF4 | NetCDF4 | NetCDF4 | NetCDF4 | NetCDF4 |
* NRT is not available for 300 m (full resolution) L2 OC and IOP products
Societal Impact
Ocean color data provides crucial insights into marine ecosystems and the effects of ocean acidification. This Satellite Needs Working Group (SNWG) solution supports the monitoring and management of coastal water quality and marine protected areas, providing essential information for protecting human and ecosystem health and for aquatic ecosystem modeling.
Solution Resources
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