Alpha Jet Atmopsheric eXperiment Meteorological Measurement System (MMS) Data

The Alpha Jet Atmospheric eXperiment (AJAX) is a partnership between NASA's Ames Research Center and H211, L.L.C., facilitating routine in-situ measurements over California, Nevada, and the coastal Pacific in support of satellite validation. The standard payload complement includes rigorously-calibrated ozone (O3), formaldehyde (HCHO), carbon dioxide (CO2), and methane (CH4) mixing ratios, as well as meteorological data including 3-D winds. Multiple vertical profiles (to ~8.5 km) can be accomplished in each 2-hr flight. The AJAX project has been collecting trace gas data on a regular basis in all seasons for over a decade, helping to assess satellite sensors' health and calibration over significant portions of their lifetimes, and complementing surface and tower-based observations collected elsewhere in the region.

AJAX supports NASA's Orbiting Carbon Observatory (OCO-2/3) and Japan's Greenhouse Gases Observing Satellite (GOSAT) and GOSAT-2, and collaborates with many other research organizations (e.g. California Air Resources Board (CARB), NOAA, United States Forest Service (USFS), Environmental Protection Agency (EPA)). AJAX celebrated its 200th science flight in 2016, and previous studies have investigated topics as varied as stratospheric-to-tropospheric transport, forest fire plumes, atmospheric river events, long-range transport of pollution from Asia to the western US, urban outflow, and emissions from gas leaks, oil fields, and dairies.

Data and Resources

Additional Info

Field	Value
Maintainer	Earthdata Forum
Last Updated	September 15, 2026, 02:54 (UTC)
Created	April 1, 2025, 14:18 (UTC)
accessLevel	public
bureauCode	{026:00}
catalog_conformsTo	https://project-open-data.cio.gov/v1.1/schema
harvest_object_id	1c316d36-29fa-4c83-a9dc-7f114c27bfcb
harvest_source_id	b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title	Science Discovery Engine
identifier	10.5067/ASDC/AJAX_MMS
license	https://www.usa.gov/government-works
modified	2026-09-07T22:16:02Z
programCode	{026:000}
publisher	NASA/LARC/SD/ASDC
resource-type	Dataset
source_datajson_identifier	true
source_hash	eff800b37fb11a601a515d525ea8a75fc8d0b0cbd82a18b10eafd2917e3e6f06
source_schema_version	1.1
spatial	["CARTESIAN", [{"NorthBoundingCoordinate": 42, "SouthBoundingCoordinate": 34, "EastBoundingCoordinate": -105.2, "WestBoundingCoordinate": -125.39}]], Maximum Altitude, 8.5 km
temporal	2013-06-20/2019-07-19
theme	{"Earth Science"}