Global Ocean Apparent Visible Wavelength from ENVISAT MERIS Satellite

AVW (Apparent Visible Wavelength) quantifies the spectral center of water-leaving reflectance in nanometers, indicating ocean water type from blue, clear waters to green/brown, productive waters. The dataset is a Level-4 global mapped product derived from the ENVISAT MERIS satellite sensor, processed by the OB_CLOUD organization. The last recorded update for this version was in May 2012.

Use Cases

• Classify global ocean water types using the avw value to distinguish oligotrophic from productive waters.
• Guide algorithm selection for chlorophyll-a (chlor_a) retrieval by using avw as a contextual indicator of optical complexity.
• Detect regional changes in marine ecosystems by analyzing temporal trends in the avw geophysical variable.
• Correlate avw with other ocean-color products like Kd_490 and PAR for integrated studies of light attenuation and primary production.

Strengths

• Provides a single, globally mapped geophysical variable (avw) for ocean color analysis.
• Derived from the ENVISAT MERIS satellite, a dedicated mission for land and ocean observation.

Limitations

• Data recency is limited, with the last update noted in 2012, potentially missing recent trends.
• Interpretations of the avw metric can vary in optically complex coastal and inland waters, as noted in the description.

Provenance

Source

ENVISAT MERIS satellite sensor, processed by OB_CLOUD.

Collection Method

Satellite remote sensing, Level-4 processing (gridded and mapped).

Time Range

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Freshness

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Geography

Global ocean coverage.