MODIS Aqua Near-Real-Time Aerosol Swath Data at 3-Kilometer Resolution

MODIS/Aqua's Near Real Time aerosol product provides a 3-kilometer spatial resolution, a significant increase from the standard 10-kilometer product for localized air quality analysis. It delivers global aerosol optical properties, including optical depth and size distribution, over ocean and land surfaces. This Level-2 swath data is produced by NASA's LANCEMODIS team using the Dark Target algorithm on observations from the Aqua satellite.

Use Cases

• Modeling localized particulate matter (PM2.5) concentrations by correlating ground sensor data with Optical_Depth_Land_And_Ocean and Aerosol_Type_Land fields.
• Tracking aerosol plume dispersion from wildfires or volcanic eruptions using the time-series of Image_Optical_Depth_Land_And_Ocean across consecutive Scan_Start_Time swaths.
• Studying aerosol radiative effects at a regional scale by analyzing Scattering_Angle and Corrected_Optical_Depth_Land parameters alongside Solar_Zenith geometry data.
• Investigating urban air pollution 'hotspots' by mapping high-resolution Optical_Depth_Ratio_Small_Land values against Land_sea_Flag classifications.
• Assessing retrieval algorithm performance over different surfaces by comparing Fitting_Error_Land and Surface_Reflectance_Land values with the Land_Ocean_Quality_Flag.

Strengths

• Provides aerosol data at a 3-kilometer spatial resolution, enabling analysis of local-scale phenomena.
• Delivers near-real-time data (NRT) for monitoring dynamic atmospheric events.
• Includes comprehensive aerosol parameters such as optical depth, size ratios, and quality flags for both land and ocean.

Limitations

• The product is less validated than the standard 10km product, with only AOD at 550 nm studied in depth.
• Known artifacts exist over urban surfaces, limiting accuracy for city-scale air quality studies.
• Aerosol-cloud interaction studies are cautioned due to unknown effects in cloud proximity.

Provenance

Source

NASA LANCEMODIS, from the MODIS instrument on the Aqua satellite.

Collection Method

Satellite remote sensing using the Dark Target (DT) aerosol retrieval algorithm on 5-minute Level-2 swath data.

Freshness

Near Real Time (NRT)

Geography

Global over ocean, near-global over land.