NOAA-21 VIIRS satellite data provides a global measure of ocean color spectral shape, known as Apparent Visible Wavelength (AVW), reported in nanometers. The dataset is produced by the OB_CLOUD organization and is identified as version 2025.0. It is used for water-type classification and guiding chlorophyll retrieval algorithms.
Use Cases
- Classify water types (e.g., oligotrophic vs. productive) using the avw variable.
- Guide selection or blending of chlorophyll-a (chlor_a) retrieval algorithms based on avw values.
- Detect regional changes in ocean optical properties over time by analyzing avw time-series.
- Provide context for other variables like Kd_490 or PAR by correlating them with the avw feature.
Strengths
- Global spatial coverage from the NOAA-21 VIIRS satellite sensor.
- Includes quality flags for cloud, glint, and aerosol to aid data filtering.
- Designed for integration with related ocean-color products like chlor_a and Kd_490.
Limitations
- Interpretation of the avw variable can be ambiguous in optically complex coastal and inland waters.
- Specific row count, temporal range, and data volume are unknown.
- Requires careful review of quality flags to filter invalid observations.
Provenance
- Source
- OB_CLOUD organization, likely via NASA Earthdata (nasa_earthdata platform).
- Collection Method
- Derived from Level-4 processed data from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the NOAA-21 satellite.
- Time Range
- null
- Freshness
- null
- Geography
- Global ocean coverage.