SHUTTLE SOLAR BACKSCATTER UV OBSERVATIONS OF NITRIC-OXIDE IN THE UPPER-STRATOSPHERE, MESOSPHERE, AND THERMOSPHERE - COMPARISONS WITH THE HALOGEN OCCULTATION EXPERIMENT

The shuttle solar backscatter ultraviolet (SSBUV) spectrometer measure d nitric oxide (NO) gamma(1,0) and gamma(0,2) band solar fluorescence at 215 and 247 nm, respectively, over a total of four orbits in April 1993 and eight orbits in March 1994. From nadir observations the appar ent NO column abundance down to 1 mbar was inferred as a function of l atitude and longitude using modeled gamma band emission rate factors, SSBUV 5 results show a factor of 2 increase in NO from 20 degrees S-20 degrees N to 40 degrees-60 degrees S and a large variation of NO with a strong dependence on geomagnetic latitude near 52 degrees S, Nimbus 7 solar backscatter ultraviolet (SBUV) spectrometer NO gamma band flu orescence observations made between 1979 and 1986 were compared with S SBUV observations, and results from the two experiments are consistent for the latitudes observed by SSBUV. Coincident with some of the SSBU V solar fluorescence observations were absorption observations in the 5.3 mu m band of NO by the Halogen Occultation Experiment (HALOE), A o ne-dimensional model was used to adjust the HALOE density profiles inf erred from sunrise occultations to the local solar time of the SSBUV o bservations, The emission rate factor model was used to convert these density profiles to nadir intensities for direct comparison with SSBUV observations. Results show that HALOE inferred intensities are genera lly within 25% of SSBUV observations on the same day.