Satellite observations of daytime and nighttime ozone in the mesosphere and lower thermosphere

Abstract

[1] The global distribution of mesospheric and lower thermospheric ozone 9.6 mm infrared emissions was measured by the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment during two Space Shuttle missions in November 1994 and August 1997. The radiances measured by CRISTA have been inverted to O 3 number densities in the 50-95 km range by using a nonlocal thermodynamic equilibrium model. A detailed sensitivity study of retrieved O 3 number densities has been carried out. The ozone abundance profiles show volume mixing ratios of 1-2 ppmv at the stratopause, 0.5 ppmv or less around 80 km, and typically 1 ppmv during daytime and 10 ppmv during nighttime at the secondary maximum. The agreement with other experiments is typically better than 25%. The global distribution of upper mesospheric ozone shows significant latitudinal gradients and an enhancement in the equatorial upper mesosphere. At the polar night terminator a third ozone maximum is observed. Three-dimensional model results indicate that the latitudinal gradients are significantly influenced by solar tides.

Electron density profiles in the quiet lower ionosphere based on the results of modeling and experimental data

“…Measurements (Zommerfields et al, 1989;Fussen et al, 2000;Kaufmann et al, 2003;Polyakov et al, 2005) and theoretical investigations Laird, 1970, 1972;Thomas and Bowman, 1972;Zadorozhny, 1982;Rodrigo et al, 1986;Sandor et al, 1997) show substantial diurnal variations of ozone concentration with maximum values at nighttime. Theoretical values of ozone numerical density are rather close to experimental values.…”

On the quality of the Nimbus 7 LIMS version 6 ozone for studies of the middle atmosphere

“…Those so-called, non-LTE radiances affect the retrieved ozone mixing ratio slightly at even lower altitudes, due to the associated, non-linear effects for the retrieval from the optically-thick, strong ozone lines of the upper stratosphere [15]. For example, analogous non-linear, non-LTE processes have been shown to affect the limb infrared retrieval of daytime radiances of water vapor in the 6 to 7 µm region even down to the upper stratosphere [16].…”

The influence of ozone concentration on the lower ionosphere – modelling and measurements during the 29–30 October 2003 solar proton event

“…The height distribution of the O 3 -density in the mesosphere, its seasonal and diurnal variations and the secondary peak have been explained by theoretical investigations and by modelling Laird, 1970, 1972;Ogawa and Shimazaki, 1975;Swider et al, 1978;Keneshea et al, 1979;Thomas and Bowman, 1985;Rodrigo et al, 1986;Sandor et al, 1997;Marsh et al, 2003;Jackman et al, 1995Jackman et al, , 2005. The primary chemical production mechanism for odd oxygen in the thermosphere and mesosphere is photodissociation of molecular oxygen.…”

“…Figure 1 presents examples of the height distribution of the O 3 concentration in the mesosphere during daytime, obtained from measurements and as a result of theoretical studies. Measurements show substantial diurnal variations at mesospheric altitudes with maximum concentrations at nighttime and a secondary peak above 80 km (Llewellyn and Witt, 1977;Weeks et al, 1972Weeks et al, , 1978Wilson and Schwartz, 1981;Ulwick et al, 1987;Zommerfields et al, 1989;Zhou et al, 1998;Sandor et al, 1997;Gumbel et al, 1998;Fussen et al, 2000;Kaufmann et al, 2003;Polyakov et al, 2005;Kyrölä et al, 2006).…”