PACE-PAX CIRPAS Twin Otter Facility Instrument Data

PACE-PAX_CIRPAS-Facility_AircraftInSitu_CIRPAS-TO_Data is the facility instrument data collected onboard the Twin Otter aircraft flying the CIRPAS suite of instruments during the Plankton, Aerosol, Cloud, ocean Ecosystem Postlaunch Airborne eXperiment (PACE-PAX) campaign. Data from the Cloud and Aerosol Spectrometer (CAS), Cloud Imaging Probe (CIP), and the Passive-Cavity Aerosol Spectrometer Probe (PCASP) instruments are featured in this collection. Data collection for this product is complete.

The PACE-PAX campaign was conducted in September 2024 to gather data for the validation and refinement of data products generated by the PACE satellite mission. PACE-PAX obtained measurements over Southern and Central California and nearby coastal regions. Scheduled for roughly 9 months after the launch of PACE, sixty flight hours were planned for each of the two aircraft, NASA’s ER-2 high-altitude aircraft, and the CIRPAS Twin Otter aircraft (in situ sampling). Based out of their respective home airports (NASA Armstrong Flight Research Center for the ER-2 and Marina Municipal Airport for the Twin Otter), flights were coordinated between the two aircraft, PACE satellite overpasses, and ground and ocean-based observations. With a robust suite of in situ and remote sensing instruments, and ground-based observations, PACE-PAX validated and refined PACE data products and identified any potential errors or biases in the measurements, which is essential for ensuring the accuracy and reliability of the PACE data products and maximizing the scientific value of the mission. The following were validation objectives for PACE-PAX: Validate new retrieval parameters; Assess spatial and temporal scale impact on validation; Validate within the instrument swath of all PACE instruments; Validate radiometric and polarimetric properties; Target specific geometries, season, and time of day; and focus on specific processes or phenomena (e.g., high-aerosol loads over land and ocean, multiple aerosol layers).

Data and Resources

Additional Info

Field	Value
Maintainer	Earthdata Forum
Last Updated	June 22, 2026, 22:50 (UTC)
Created	June 3, 2026, 02:04 (UTC)
accessLevel	public
bureauCode	{026:00}
catalog_conformsTo	https://project-open-data.cio.gov/v1.1/schema
harvest_object_id	d7a4b765-0164-4085-80b1-3dbfcb330761
harvest_source_id	b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title	Science Discovery Engine
identifier	10.5067/ASDC/SUBORBITAL/PACE-PAX/CIRPAS-TO/CIRPAS-Facility_AircraftInsitu_1
license	https://www.usa.gov/government-works
modified	2026-06-15T22:16:00Z
programCode	{026:000}
publisher	NASA/LARC/SD/ASDC
resource-type	Dataset
source_datajson_identifier	true
source_hash	7fddef37d9443f55737bfdf63ae172e4dc973be20167ad4adfdb12c969d0dcff
source_schema_version	1.1
spatial	["CARTESIAN", [{"NorthBoundingCoordinate": 38.11, "WestBoundingCoordinate": -125.33, "EastBoundingCoordinate": -116.98, "SouthBoundingCoordinate": 33.49}]]
temporal	2024-08-29/2024-09-28
theme	{"Earth Science"}