Nitric acid column densities derived from atmospheric infrared spectral emission data measured from the NSF USARP Cl30 research aircraft in the Spring of 1978 are presented, summarized by latitude. An increase of the column density with latitude is noted, along with a longitudinal asymmetry in the latitudinal dependence. Column densities range in values from 1.2¿0.2¿1020 molecules m-2 at 53 ¿S latitude to 3.4¿0.7¿1020 molecules m-2 at 89 ¿S latitude. Also, the liquid helium cooled spectral radiometer used to obtain the data and the associated calibration procedures are described.