Aqua Satellite Atmospheric Water Vapor Measurements at 1km and 5km Resolution

Total precipitable water vapor amounts derived from the MODIS instrument aboard NASA's Aqua satellite. Data is provided in 5-minute Level 2 swaths at two spatial resolutions: 1 km from a near-infrared algorithm for daytime land areas and 5 km from an infrared algorithm for day and night. The product is generated by the MODIS Adaptive Processing System (MODAPS) and distributed by LAADS.

Use Cases

• Model regional humidity and moisture transport by analyzing the 5-km infrared-derived precipitable water vapor profiles across day and night cycles.
• Compare algorithm performance by evaluating water-vapor estimates from the 1-km near-infrared retrievals over clear land against the 5-km infrared data.
• Study diurnal cycles of atmospheric water content by leveraging the infrared algorithm's day-and-night capability.
• Analyze spatial patterns of water vapor over sun glint areas of the ocean using the specialized near-infrared retrievals for those regions.
• Integrate Aqua platform MYD05_L2 data with Terra platform MOD05_L2 data for multi-satellite analysis of global water vapor trends.

Strengths

• Provides data at two distinct spatial resolutions: 1 km for near-infrared and 5 km for infrared retrievals.
• Infrared algorithm enables water vapor profile derivation during both daytime and nighttime.
• Collection 6.1 represents an improved version addressing issues in prior Collection 6 Level-1B data.

Limitations

• Near-infrared algorithm retrievals are limited to daytime over specific surfaces and are no longer being updated by NASA for Collection 6.1.
• Infrared algorithm requires at least nine cloud-free field of views to generate data at 5-km resolution, potentially reducing coverage in cloudy regions.
• Sample size, temporal range, and specific data volume metrics are not provided in the description.

Provenance

Source

NASA Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument on the Aqua satellite.

Collection Method

Derived using two algorithms: a near-infrared algorithm for daytime land/cloud areas and an infrared algorithm for day/night profiles.

Time Range

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Freshness

Data is provided in 5-minute swaths; update frequency is tied to satellite overpasses.

Geography

Global coverage from satellite swaths.