IMOS - NOAA20 VIIRS: Diffuse Attenuation Coefficient (Kd490) Daily Data

IMOS provides satellite-derived ocean data from the NOAA20 platform's VIIRS sensor. The dataset contains daily estimates of the diffuse attenuation coefficient at 490nm wavelength (Kd490), which indicates light penetration in the water column. The algorithm is based on a semi-empirical model using water-leaving radiances at 490nm and 555nm, as described by NASA's Ocean Color team.

Use Cases

• Modeling primary productivity in ocean ecosystems based on light attenuation data.
• Monitoring coastal water quality and turbidity changes over time using satellite-derived Kd490.
• Calibrating and validating bio-optical models for remote sensing of ocean properties.
• Studying the spatial distribution of particulate matter in the water column based on the diffuse attenuation coefficient.

Strengths

• Data is derived from the NOAA20 satellite's VIIRS sensor, a recognized source for ocean color observations.
• The algorithm for Kd490 is documented by NASA's Ocean Color team, providing methodological transparency.
• The dataset was last updated on 2026-07-10, suggesting ongoing maintenance.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and total data size are unknown, which may limit suitability assessment.
• The description metadata is limited; actual data quality and spatial coverage require manual inspection.

Provenance

Source

Australian Ocean Data Network (AODN) via the Integrated Marine Observing System (IMOS).

Collection Method

Satellite remote sensing via the VIIRS sensor on the NOAA20 platform, processed using a semi-empirical algorithm.

Freshness

Last updated 2026-07-10 02:30:19.739586; freshness should be verified.

Geography

Likely covers ocean areas observed by the NOAA20 satellite, but specific spatial coverage is not detailed.