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    • This is a Non-Federal dataset covered by different Terms of Use than Data.gov.

    SASS (Subsonics Assessment) Ozone and NOx Experiment (SONEX) Photolysis Frequencies (J-Values)

    Metadata Updated: February 22, 2025

    SONEX_jValue_AircraftInSitu_DC8_Data_1 is the photolysis frequencies (j-values) measured along the DC-8 flight by the Scanning Actinic Flux Spectroradiometers (SAFS). Data collection is complete.

    The SASS (Subsonics Assessment) Ozone and NOx Experiment (SONEX) was an international, multi-organizational mission that took place in October-November 1997. NASA was the US sponsor of SONEX that partnered with POLINAT-2 (Pollution from Aircraft Emissions in the North Atlantic Flight Corridor) funded by the German DLR (Deutsches Zentrum für Luft- und Raumfahrt) or German Aerospace Agency. NASA flew the DC-8 aircraft out of NASA/Ames Research Center. DLR operated an instrumented Falcon 20 aircraft. The staging locations for NAFC sampling were primarily Bangor, Maine (US), and Shannon, Ireland. Subsonic aircraft emissions impact several aspects of atmospheric composition: nitrogen oxides (NOx), CO, and hydrocarbons from emissions can perturb upper tropospheric/lower stratospheric (UT/LS) ozone; water vapor, soot, and sulfur oxides (SOx) emitted by aircraft may perturb clouds and aerosols, changing UT/LS radiative forcing and global temperature. In SONEX and POLINAT, flights were conducted in the vicinity of the North Atlantic Flight Coordinator (NAFC) to observe the impact of aircraft emissions on NOx and ozone (O3). The DC-8 aircraft payload (Singh et al., 1999) primarily measured in-situ CO, CO2, hydrocarbons/halocarbons, O3, aerosols (Dibb et al., 2000), OH/HO2, water vapor, nitric acid (Talbot et al., 1999), photolysis rates, temperature, pressure, winds, NOx, and NOy. Three sampling approaches were implemented during SONEX. First, special meteorological (Fuelberg et al., 2000) were developed to allow targeted sampling for air parcels affected by aircraft emissions and various meteorological events, e.g., convection, lightning (Jeker et al., 2000), stratospheric intrusions (Cho et al., 2000). Second, because the NAFC had not been extensively sampled in the past, it was important for SONEX to characterize the climatology of trace species like CN (Wang et al., 2000), NOx and NOy (Koike et al., 2000). Third, tracers (Simpson et al., 2000; Thompson et al., 1999) and model sensitivity studies (Meijer et al., 2000) were employed for Air Mass Identification. This sampling strategy answered the following questions: Where and when are air masses found with the greatest aircraft influence? When and where was stratospheric air sampled? SONEX showed a substantial impact of aircraft emissions on UT/LS NOx and CN in the vicinity of fresh aircraft emissions. However, during October-November 1997 over the NAFC, UT/LS NOx was dominated by surface emissions redistributed by convection and augmented by lightning.

    Access & Use Information

    Public: This dataset is intended for public access and use. Non-Federal: This dataset is covered by different Terms of Use than Data.gov. License: No license information was provided.

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    Dates

    Metadata Created Date February 22, 2025
    Metadata Updated Date February 22, 2025

    Metadata Source

    Harvested from nasa test json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date February 22, 2025
    Metadata Updated Date February 22, 2025
    Publisher NASA/LARC/SD/ASDC
    Maintainer
    Identifier C2662394953-LARC_ASDC
    Data First Published 1997-10-07
    Language en-US
    Data Last Modified 2025-02-19
    Category SONEX, geospatial
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 1a9174e0-4c9e-4efa-b651-fca69e696797
    Harvest Source Id a73e0c30-4684-40ef-908e-d22e9e9e5f86
    Harvest Source Title nasa test json
    Homepage URL https://doi.org/10.5067/ASDC/SUBORBITAL/SONEX_jValue_AircraftInSitu_DC8_Data_1
    Metadata Type geospatial
    Old Spatial <?xml version="1.0" encoding="UTF-8"?><gml:Polygon xmlns:gml="http://www.opengis.net/gml/3.2" srsName="EPSG:9825"><gml:outerBoundaryIs><gml:LinearRing><gml:posList>19.89 -129.403 19.89 13.023 69.127 13.023 69.127 -129.403 19.89 -129.403</gml:posList></gml:LinearRing></gml:outerBoundaryIs><gml:innerBoundaryIs></gml:innerBoundaryIs></gml:Polygon>
    Program Code 026:001
    Source Datajson Identifier True
    Source Hash 54f5412ac3653cf844cfaca5b061f7bef90b44ae29538314752581a8419df07e
    Source Schema Version 1.1
    Spatial
    Temporal 1997-10-07T00:00:00Z/1997-11-13T23:59:59.999Z

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