The Stratospheric Photochemistry, Aerosols and Dynamics Expedition (SPADE) campaign was a field mission conducted by NASA from October 1992 to October 1993. SPADE’s primary goal was to quantify key chemical reaction rates affecting ozone production and loss. 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.

ER-2 Instruments:

Instrument	Full Name	Contact Person	Team	Type	Measurements
Harvard CO2	HIgh-Sensitivity Fast-Response CO2 Analyzer	Steven C. Wofsy	HUPCRS	Spectrometer (in situ)	CO2
HOx	Harvard Hydroxyl Experiment	James Anderson	Harvard H2O	Fluorescence, Laser absorption	OH, HO2
MMS	Meteorological Measurement System	T. Paul Bui	MMS		3D Wind, Turbulence, Temperature, Position, Velocities, Attitudes, True-Airspeed, Potential Temperature
ACATS	Airborne Chromatograph For Atmospheric Trace Species	James W. Elkins	PANTHER/UCATS	Gas chromatography	CFCl3, CF2Cl2, CF2ClCFCl2, CH3CCl3, CCl4, Halon-1211, CHCl3, CH4, H2, N2O, SF6
FPCAS	FSSP-300 Aerosol Spectrometer				Aerosol Scattering Ratio
Lyman Alpha-Hygrometer	Lyman Alpha-Hygrometer	Ken Kelly	NOAA UASO3
ATLAS	Airborne Tunable Laser Absorption Spectrometer	Max Loewenstein	ATLAS	Spectrometer (in situ)	N2O, CH4, CO, O3
CPFM	Composition and Photo-Dissociative Flux Measurement	C. Thomas McElroy	CPFM	Radiometer, Spectrometer (in situ)	Solar flux
NOAA O3	O3 Photometer (NOAA)	Troy Thornberry	NOAA UASO3	Photometer	O3
ClO/BrO	Multiple Axis Resonance Fluorescence Chemical Conversion Detector for ClO and BrO	James Anderson	Harvard Halogen	Fluorescence	ClO, BrO
ALIAS	Aircraft Laser Infrared Absorption Spectrometer	Lance Christensen	ALIAS	Laser absorption, Spectrometer (in situ)	N2O, H2O isotopes, H2O, CO, CH4, CO2 isotopes, HCl
CNC	Condensation Nuclei Counter	James Wilson	FCAS / NMASS	CN counter	CCN