Solar energy deposition rates in the mesosphere derived from airglow measurements: Implications for the ozone model deficit problem

Abstract

Abstract. We derive rates of energy deposition in the mesosphere due to the absorption of solar ultraviolet radiation by ozone. The rates are derived directly from measurements of the 1.27-gin oxygen dayglow emission, independent of knowledge of the ozone abundance, the ozone absorption cross sections, and the ultraviolet solar irradiance in the ozone Hartley band. Fifty-six months of airglow data taken between 1982 and 1986 by the near-infrared spectrometer on the Solar-Mesosphere Explorer satellite are analyzed. The energy deposition rates exhibit altitude-dependent annual and semi-annual variations. We also find a positive correlation between temperatures and energy deposition rates near 90 kin at low latitudes. This correlation is largely due to the semiannual oscillation in temperature and ozone and is consistent with model calculations. There is also a suggestion of possible tidal enhancement of this correlation based on recent theoretical and observational analyses. The airglow-derived rates of energy deposition are then compared with those computed by multidimensional numerical models. The observed and modeled deposition rates typically agree to within 20%. This agreement in energy deposition rates implies the same agreement exists between measured and modeled ozone volume mixing ratios in the mesosphere. Only in the upper mesosphere at midlatitudes during winter do we derive energy deposition rates (and hence ozone mixing ratios) consistently and significantly larger than the model calculations. This result is contrary to previous studies that have shown a large model deficit in the ozone abundance throughout the mesosphere. The climatology of solar energy deposition and heating presented in this paper is available to the community at the Middle Atmosphere Energy Budget Project web site at http://heat-budget.gats-inc.com.

A search for an anticorrelation between H2O and O3 in the lower mesosphere

“…Since the new data of Conway et al [2000] invalidate this suggestion, we will use the standard JPL value for . Our residual deficit of 5–10% is in agreement with the recent analysis of Solar Mesosphere Explorer ozone of Mlynczak et al [2000] given the 20% systematic uncertainty they place on their result. One exception to this pattern is at 0.1 mbar for SR conditions where the model falls 30% below the data.…”

Comparison of a photochemical model with observations of mesospheric hydroxyl and ozone

“…It is likely that the model ozone deficit is in the 10%–50% range which, as noted by Mlynczak et al . [], is much smaller than the first analyses in the 1980s [ Rusch and Eckman , ]. However, as we have shown, a model ozone deficit appears to be remarkably persistent across a diverse range of observations.…”

“…As has been pointed out [Huang et al, 2008], there are large systematic uncertainties in mesospheric ozone measurements, and this complicates a precise model-measurement comparison. It is likely that the model ozone deficit is in the 10%-50% range which, as noted by Mlynczak et al [2000], is much smaller than the first analyses in the 1980s [Rusch and Eckman, 1985]. However, as we have shown, a model ozone deficit appears to be remarkably persistent across a diverse range of observations.…”

SABER observations of the OH Meinel airglow variability near the mesopause

“…Interestingly, the same diffusive mechanism was used to explain variations in mesospheric ozone [ Garcia and Solomon , 1985], since both ozone and OH emission depend critically on the distribution of atomic oxygen. More recently it was suggested that tides could play an important role in mesospheric ozone variability [ Mlynczak et al , 2000; Marsh et al , 2002]. It follows that the topic of ozone variability should also be revisited using SABER observations and three‐dimensional models.…”