The existence of a tertiary ozone maximum in the high‐latitude middle mesosphere

Abstract

Abstract. Modeling and observations provide evidence of the existence of a tertiary ozone maximum in the middle mesosphere restricted to winter high-latitudes. This local maximum occurs at approximately 72 km altitude, at latitudes just equatorward of the polar night terminator. Model analysis indicates that this maximum is the result of a decrease in atomic oxygen losses by catalytic cycles involving the odd-hydrogen species OH and HO2. In the middle mesosphere, at high latitudes, the atmosphere becomes optically thick to ultra-violet radiation at wavelengths below 185 nm. Since photolysis of water vapor is the primary source of oddhydrogen, reduced ultra-violet radiation results in less oddhydrogen and consequently lower oxygen loss rates. The consequent increase in atomic oxygen results in higher ozone because atomic oxygen recombination remains the only significant source of ozone in the mesosphere.

Solar particle effects on minor components of the Polar atmosphere

“…In a similar way it is possible to explain the existence of the so-called "third ozone maximum" (Marsh et al, 2001;Degenstein et al, 2005) in the mesospheric winter hemisphere at high latitudes and at about 72 km of altitude. In fact, during the night state, the reduced production of HO x components (see Introduction) facilitates the increase in the ozone concentration, but during the "day" such an increase is prevented.…”

Retrieval of stratospheric ozone profiles from MIPAS/ENVISAT limb emission spectra: a sensitivity study

“…This is the tertiary ozone maximum just equatorward of the polar night terminator as described by Marsh et al (2001). 71 individual ozone profiles, which cover a range of atmospheric conditions, namely the Arctic pre-vortex, northern fall and southern spring mid-latitudes, the tropics and the final stage of the Antarctic vortex, were derived from orbit 8597.…”

Comparison of ozone profiles and influences from the tertiary ozone maximum in the night-to-day ratio above Switzerland

“…Sonnemann et al, 2007;Hartogh et al, 2004) also known as the tertiary ozone maximum (e.g. Sofieva et al, 2009;Degenstein et al, 2005;Marsh et al, 2001). Sonnemann et al (2007) reported that the MMM is a phenomenon that occurs at high latitudes close to the polar night terminator at around 72 km altitude during nighttime in winter and extends into middle latitudes with decreasing amplitude.…”

“…Sonnemann et al (2007) reported that the MMM is a phenomenon that occurs at high latitudes close to the polar night terminator at around 72 km altitude during nighttime in winter and extends into middle latitudes with decreasing amplitude. Marsh et al (2001) interpreted the tertiary peak by considering that in the middle mesosphere during winter, with a solar zenith angle close to 90 • , the atmosphere becomes optically thick to UV radiation at wavelengths below 185 nm, and, since photolysis of water vapour (Reaction R1) is the primary source of odd hydrogen, reduced UV radiation results in less odd hydrogen. The lack of odd hydrogen needed for the catalytic depletion of odd oxygen (Reactions R2, R3, and R4), in conjunction with an unchanged rate of odd-oxygen production (Reaction R5), leads to an increase in odd oxygen.…”