Mesospheric HOx chemistry from diurnal microwave observations of HO2, O3, and H2O

摘要: Microwave (λ ∼1.2 mm) spectral emission line observations of HO2, O3, and H218O from the upper stratosphere mesosphere (45–80 km) were obtained in April 1992, January 1993, December 1996, using Kitt Peak National Radio Astronomy Observatory (NRAO). Significant improvements to this, only method for making mesospheric HO2 measurements, have been made with hardware upgrades allowing observation a stronger than described previous work. Data analysis has improved by (1) recalibration (primarily astronomical) instrument atmospheric studies, (2) incorporation updated laboratory spectroscopic work, (3) use an photochemical model. Diurnal data analyses employing 30 min 2 hour show measured abundances at 50–80 km altitude are 23–47% higher model values mid day, agree prior 0900 local time (LT), exceed mixing ratios 70–100% immediately after sunset. Coordinated diurnal measurements O3 find deficit consistent underprediction ozone seen all comparable sets. critical understanding chemistry, that simultaneous underpredictions this ozone-destroying species place stringent constraints on proposed sources error. The 0900–1800 simultaneously resolved 40% reduction rate coefficient k(HO2 + O → OH O2). We review other modeling studies change, indicating it negligible effect lower improves diverse set results mesopause.