AJAX: California and Nevada Atmospheric Trace Gas Profiles from Aircraft

Over a decade of routine in-situ atmospheric measurements from the Alpha Jet Atmospheric eXperiment (AJAX) partnership between NASA Ames and H211, L.L.C. The project celebrated its 200th science flight in 2016 and collects calibrated ozone, formaldehyde, carbon dioxide, and methane mixing ratios, plus meteorological data, during 2-hour flights reaching ~8.5 km altitude over California, Nevada, and the coastal Pacific.

Use Cases

• Validate satellite sensor calibration and health for OCO-2/3 and GOSAT based on in-situ trace gas measurements.
• Analyze pollution transport events, such as long-range transport from Asia or urban outflow, based on vertical profile data.
• Study specific atmospheric phenomena like forest fire plumes or atmospheric rivers based on multi-species gas and wind measurements.
• Complement surface and tower-based air quality observations with vertical profile data from aircraft.

Strengths

• Data collected for over a decade across all seasons, providing long-term temporal coverage.
• Includes rigorously-calibrated measurements for multiple key trace gases (O3, HCHO, CO2, CH4) and 3-D winds.
• Supports major satellite validation efforts for NASA and Japanese missions.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is geographically focused on California, Nevada, and the coastal Pacific.

Provenance

Source

National Aeronautics and Space Administration (NASA) Ames Research Center in partnership with H211, L.L.C.

Collection Method

Routine in-situ measurements collected via instrumented Alpha Jet aircraft during 2-hour science flights.

Time Range

Over a decade of data, with operations including a 200th flight milestone in 2016.

Freshness

Last updated 2026-03-13 06:01:11.624414; freshness should be verified.

Geography

California, Nevada, and the coastal Pacific.