Altitude distribution of stratospheric NO₃: 1. Observations of NO₃ and related species

Abstract

Five balloon‐borne observations of the vertical profile of stratospheric NO3 and ozone were performed between 1981 and 1985 by using the star and planet occultation technique at 662 nm. During the last two flights, NO2 was also measured by the same technique at 440 nm. The latest available laboratory determination of the 662‐nm absorption cross section of NO3 has been used for the data analysis. This gives NO3 concentrations that are about a factor of 2 lower than those previously reported. The concentration of NO3 increases with altitude, from about 1×107 molecules cm−3 around 22 km, to 2×107 molecules cm−3 at 38 km in September. A maximum value of 4×107 molecules cm−3 was observed at 38 km in May 1982. Ozone and NO2 results obtained from the same flights as NO3 are also presented. A companion paper provides details on the comparison between observed and modeled NO3 vertical profiles.

Nocturnal vertical distribution of stratospheric O3, NO2 and NO3 from balloon measurements

“…Measurements of these species had been previously made by our group with the CMS (Compos6s Minoritaires Stratosph6riques)instrument and the same experiment technique [Rigaud et al, 1983;Naudet et al, 1989]. Contrary to AMON, this instrument was not able to measure simultaneously NO2, NO3, and ozone.…”

Retrieval of vertical profiles of NO3 from zenith sky measurements using an optimal estimation method

“…There are very few other vertically resolved measurements in the stratosphere. Naudet et al [1989] retrieved five separate profiles using a combination of stellar and planetary occultation from a balloon‐borne instrument. Their measurements range in height from 22 to 38 km and the variability in concentration, indicated by the error bars in Figure 2, agrees with the single profile of Smith and Solomon [1990].…”

“…Here, the available data have been averaged across their height bin to provide an average a priori profile, x a , and where sufficient data are available, the entire range of data within each height bin is used to estimate the a priori error, rather than the variance. This approach is possible from the ground to 3 km and also between 22 and 39 km where the balloon based measurements of Naudet et al [1989] are available. Above 40 km the a priori error was set to be equal to the variability at 39 km, when expressed as a mixing ratio.…”

Heterogeneous reactions of suspended parathion, malathion, and fenthion particles with NO3 radicals

“…The concentration of NO 3 radicals is reported to reach values of up to 4.0 Â 10 7 molecules cm À3 in the stratosphere (Naudet et al, 1989) and 2.0 Â 10 9 molecules cm À3 in the troposphere at nighttime (Platt et al, 1980). Despite these significant concentrations, few studies on the heterogeneous reactions of airborne OPPs with NO 3 radicals have hitherto been performed .…”