Knowledge Bank

The Smithsonian Astrophysical Observatory far-infrared spectrometer (FIRS-2) measures vertical mixing ratio profiles in the stratosphere from a ballon platform. The FIRS-2 is a high-resolution $(0.004cm-1unapodized)$ two-beam Fourier transform spectrometer which measures thermal emission in the regions $80-210cm-1$ and $350-700cm-1$. Observations are made at various elevation angles, with absolute pointing referenced to a gyroscope and accelerometer-stabilized single-axis platform. Molecules currently measured include $OH,HO2,H2O,H2O2,O3P,O2,O3,HCl,HF,HBr,HOCl,HOBr,CO,CO2,N2O,NO2,HNO3,andHCN$. The measurements, the development of the relevant spectroscopy, and the application of the measurments to improving models of the photochemistry of the ozone layer are discussed.