UARS MLS: Daily Vertical Profiles of Stratospheric Chemistry

NASA's UARS Microwave Limb Sounder (MLS) Level 3AL dataset provides daily vertical profiles of atmospheric constituents and temperature. Data cover altitudes from 10 to 85 km with a 2.5 km resolution, collected between latitudes 34°S–80°N and 80°S–34°N on alternating 36-day yaw cycles. The product includes nine daily granules for temperature, geopotential height, and concentrations of O3, H2O, CH3CN, ClO, HNO3, and SO2, processed primarily with the version 5 algorithm.

Use Cases

• Tracking chlorine monoxide (ClO) and ozone (O3) concentrations to study polar ozone destruction cycles.
• Analyzing vertical water vapor (H2O) profiles to understand stratospheric humidity and transport.
• Investigating sulfur dioxide (SO2) distributions following volcanic eruptions for atmospheric chemistry modeling.
• Using temperature and geopotential height profiles for validating atmospheric dynamics models.

Strengths

• Provides high vertical resolution (~2.5 km) profiles across a wide altitude range (10–85 km).
• Contains multiple key atmospheric species (e.g., O3, ClO, HNO3) from a single, calibrated satellite instrument.
• Offers daily temporal resolution with global coverage between 34°S–80°N and 80°S–34°N.

Limitations

• Metadata completeness is low; specific column names, row counts, and file sizes are not provided.
• H2O and O3 data from the 183 GHz radiometer are only available until April 15, 1993, due to instrument failure.
• Conflicting 'last updated' dates (1999 vs. 2026) across platforms create uncertainty about metadata freshness.

Provenance

Source

National Aeronautics and Space Administration (NASA), Upper Atmosphere Research Satellite (UARS) mission.

Collection Method

Satellite remote sensing via the Microwave Limb Sounder (MLS) instrument measuring at 63, 183, and 205 GHz.

Time Range

Data collection began with the UARS mission; specific start and end dates are not provided.

Freshness

2026-04-09 21:18:00.576437

Geography

Global coverage, alternating between latitudes 34°S to 80°N and 80°S to 34°N every ~36 days.