Comparison of mesospheric ozone abundances measured by the Solar Mesosphere Explorer and model calculations

Abstract

Ozone observations in the mesosphere obtained by the near infrared and ultraviolet spectrometers onboard the Solar Mesosphere Explorer (SME) satellite are compared to two dimensional model calculations for the month of January. In general, the model calculated abundances are somewhat smaller than those measured, but exhibit similar trends with respect to altitude and latitude. The possible causes of discrepancies include the mesospheric H2O content and photochemical reaction rates, particularly the rate of O2 photolysis.

Seasonal variability of CO in the terrestrial mesosphere

“…At this time we are unaware of any reported seasonal variations for other chemical constituents in the earth's upper mesosphere with the exception of ozone [Barth et al, 1983], which was thought to be primarily influenced by the seasonal dependence of solar insolation and atmospheric temperature [e.g., Solomon et al, 1983] fel, 1970;Offerman, 1974;Alcaydg et al, 1974]. The seasonal variation of these constituents may be explained by global circulation between the northern and southern hemispheres [Kasting and Roble, 1981].…”

Stratospheric and mesospheric HO<sub>2</sub> observations from the Aura Microwave Limb Sounder

“…However, Canty et al (2006) concluded that, at least between 25 and 60 km, the HO x Microwave Limb Sounder (MLS) and FIRS-2 observations were reasonably well described by photochemical models. In addition to these modelling discrepancies (a problem known as the HO x dilemma), models have consistently underpredicted the amounts of O 3 at such altitudes, an issue known as the O 3 deficit problem (Crutzen and Schmailzl, 1983;Solomon et al, 1983;Eluszkiewicz and Allen, 1993;Summers et al, 1997;Varandas, 2004;Siskind et al, 2013).…”

Nighttime mesospheric hydroxyl enhancements during SEP events and accompanying geomagnetic storms: Ionization rate modeling and Aura satellite observations

“…The main mechanism is through ionization by precipitating high-energy particles, e.g., protons with~5 MeV deposit their maximum energy at~75 km altitude, which leads to an efficient ionization of atmosphere at this altitude [Turunen et al, 2009;Wissing and Kallenrode, 2009]. Among other effects, SEPs create odd hydrogen (HO x , primarily hydroxyl OH and HO 2 ) species through ion chemistry and cause ozone (O 3 ) destruction in the mesosphere [Solomon et al, 1981[Solomon et al, , 1983Jackman et al, 2005Jackman et al, , 2006Jackman et al, , 2011Verronen et al, 2006Verronen et al, , 2007Damiani et al, 2008Damiani et al, , 2010Verkhoglyadova et al, 2015]. For example, tertiary ozone maximum observed in wintertime high-latitude mesosphere around that altitude range [Marsh et al, 2001] is strongly affected by SEPs [Seppälä et al, 2006;Sofieva et al, 2009].…”