SPADE ER-2 Aircraft In-Situ Trace Gas Data

SPADE had four scientific objectives. The first objective of SPADE was to study chemical processes potentially affecting ozone at altitudes most strongly influenced by stratospheric aviation. This was accomplished by making comprehensive measurements of radicals and reservoir species (HOx radicals, NO2, NO, NOy, ClO, O3, HCL, sulfate aerosols, UV, and visible irradiances).

The second objective was examining distributions of tracers whose concentrations in the lower stratospheres vary on time scales ranging from months to years. Thirdly, SPADE aimed to determine the effects of heterogeneous chemistry on concentrations of radicals and reservoir species. This was done by obtaining data for various stages of decay of the Mt.

Pinatubo aerosol, as well as examining morning-evening differences. Finally, SPADE had the objective of laying the groundwork for future 1994 field missions of the High-Speed Research Program (HSRP) and NASA’s Upper Atmosphere Research Program (UARP). In order to complete its objectives, the SPADE field team deployed the NASA ER-2 aircraft and balloon sondes.

The ER-2 was equipped with 12 instruments to collect various atmospheric measurements. Among these instruments, the High-Sensitivity Fast-Response CO2 Analyzer (Harvard CO2) collected in-situ measurements of CO2, while the Airborne Tunable Laser Absorption Spectrometer (ATLAS) recorded in-situ measurements of N2O, CH4, CO, and ozone. Another in-situ instrument was the Aircraft Laser Infrared Absorption Spectrometer (ALIAS), which collected data on N2O, H2O isotopes, H2O, CO, CH4, CO2 isotopes, and HCl.

The Airborne Chromatograph for Atmospheric Trace Species (ACTAS) instrument, a gas chromatographer, was used to collect measurements of CFCl3, SF6, N2O, CHCl3, and CH4 among others. The ER-2 was also equipped with the O3 Photometer (NOAA O3) and the Meteorological Measurement System (MMS). The NOAA O3 measured ozone in the atmosphere, while the MMS analyzed meteorological variables such as temperature, turbulence, altitudes, true air speeds, and 3D wind.

The balloon sondes were responsible for collecting measurements on temperature, geopotential, wind direction, wind speed, and dew point depression.