AVW (Apparent Visible Wavelength) quantifies the spectral center of water-leaving reflectance across the visible range, reported in nanometers. The dataset contains global binned Level-4 data from the ENVISAT MERIS satellite instrument, processed by OB_CLOUD. The data version is 2022.0, with a last recorded update in May 2012.
Use Cases
- Classify water types (e.g., oligotrophic vs. productive) based on the avw value.
- Guide chlorophyll-a (chlor_a) algorithm selection or blending using the avw feature as context.
- Detect regional changes in optical water properties over time by analyzing time-series of the avw geophysical variable.
- Study coastal optical complexity by interpreting avw alongside other variables like Kd_490 and IOPs.
Strengths
- Global spatial coverage for ocean color analysis.
- Provides a single, summarized geophysical variable (avw) for spectral shape.
Limitations
- Data temporal coverage ends with the last update in 2012, making it stale for contemporary analysis.
- Interpretation of the avw variable can be ambiguous in optically complex coastal and inland waters.
- Requires careful review of quality flags for cloud, glint, and aerosol contamination.
Provenance
- Source
- ENVISAT MERIS satellite instrument, processed by OB_CLOUD.
- Collection Method
- Satellite remote sensing data processed to Level-4 global binned product.
- Time Range
- null
- Freshness
- Last updated 2012-05-09; update frequency is null.
- Geography
- Global ocean coverage.