VIIRS/NPP Land Aerosol Optical Thickness: Daily Global 750m Grid

VNP19A2 Version 2 is a NASA/NOAA Suomi NPP satellite data product providing daily global land aerosol optical depth (AOD) at a 750-meter pixel resolution. The product includes layers for AOD, uncertainty, quality assurance, smoke plume injection height, and various atmospheric and view geometry parameters. It is produced by LPCLOUD using the VIIRS instrument and the MAIAC atmospheric correction algorithm.

Use Cases

• Monitoring daily atmospheric pollution levels based on Aerosol Optical Depth (AOD) measurements.
• Analyzing smoke plume dispersion and height based on the injection height layer.
• Studying aerosol particle size distribution over oceans based on the Angstrom Exponent layer.
• Assessing data reliability near coastlines based on the provided AOD quality assurance (QA) flags.
• Investigating the fraction of fine particulate matter based on the fine mode fraction data.

Strengths

• Provides daily global coverage, enabling time-series analysis of atmospheric aerosols.
• Offers a 750-meter spatial resolution, which is relatively high for global satellite aerosol products.
• Includes multiple derived layers such as AOD uncertainty, QA, and fine mode fraction for comprehensive analysis.

Limitations

• Known reduced accuracy at high solar zenith angles (> 78°) due to algorithmic assumptions.
• May contain artifacts and over-detected cloud masks within 1-3 pixels of coastlines.
• The ice mask is described as unreliable, and aerosol retrieval over snow uses area-averaged estimates that may not capture local variability.
• Description metadata is limited; actual data quality and column definitions require manual inspection after download.

Provenance

Source

NASA/NOAA Suomi NPP satellite, Visible Infrared Imaging Radiometer Suite (VIIRS) instrument.

Collection Method

Satellite remote sensing data processed with the Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm.

Time Range

Daily product; specific date range is unknown.

Freshness

Daily production frequency.

Geography

Global land coverage.