A system analysis approach for atmospheric observations and models: Mesospheric HO_x dilemma

Abstract

[1] A systematic consistency analysis and optimization procedure is applied to models of representative ozone, OH, and HO 2 observations in the mesosphere and upper stratosphere. The approach considers both measurement and rate parameter uncertainties. The results show some data point inconsistencies and the inability of the accepted photochemical mechanism to predict observations without unfavored large alterations of many rate constants from their consensus values. Optimization results do favor larger rate constants for OH + O and photolytic ozone and OH production.Citation: Smith, G. P., M. Frenklach, R. Feeley, A. Packard, and P. Seiler (2006), A system analysis approach for atmospheric observations and models: Mesospheric HO x dilemma,

SMILES observations of mesospheric ozone during the solar eclipse

“…The decreasing trend in the exponents of the power law at altitudes less than about 64 km results from a rapid increase in the HO X production rate through reaction (R9), and a moderate decrease through reaction (R8) [Allen et al, 1984]. Finally, we note that as described in section 1, there have been some papers reporting discrepancies between observed and modeled O 3 concentrations in the mesosphere [e.g., Sandor et al, 1997;Siskind et al, 2013;Smith et al, 2006]. Although optimization of the kinetic parameters for photochemical reactions involving O x and HO x has been suggested to solve the unsettled issue, no firm conclusion has been reached.…”

“…Finally, we note that as described in section 1, there have been some papers reporting discrepancies between observed and modeled O 3 concentrations in the mesosphere [e.g., Sandor et al ., ; Siskind et al ., ; Smith et al ., ]. Although optimization of the kinetic parameters for photochemical reactions involving O x and HO x has been suggested to solve the unsettled issue, no firm conclusion has been reached.…”

“…In the mesosphere, chain reactions involving HO X (H, OH, and HO 2 ) radicals are believed to be a dominant driver of O X loss [e.g., Allen et al, 1984;Brasseur and Solomon, 2005]. Although the mesospheric O X photochemistry seems to be relatively simple, and the chemical lifetime of O X is much shorter (≤1 h) [Brasseur and Solomon, 2005] than characteristic transport lifetimes, discrepancies between observed and modeled O 3 concentrations have been reported [e.g., Sandor et al, 1997;Siskind et al, 2013;Smith et al, 2006].…”

Uncertainty quantification: Making predictions of complex reaction systems reliable

“…The methodology tests consistency among data and models [8], explores sources of inconsistency [8], discriminates among differing models [10], makes model interval predictions [7,11], and analyzes sensitivity of uncertainty propagation [12]. Applications to date of the Data Collaboration methodology include combustion science [7,8,12,13] and engineering [14], atmospheric chemistry [15], and system biology [10,16,17].…”

Superconducting integrated receiver development for TELIS

“…The fact that TELIS can retrieve almost all species appearing in the catalytic ozone depletion cycles will put the existing atmospheric chemistry models to stringent tests. In the upper stratosphere chemistry models are less accurate: ozone concentrations are underpredicted, HO 2 is underpredicted, and OH is overpredicted [17,18]. Observing all species simultaneously will shed light on the production and loss mechanisms of HO x and the partitioning between OH and HO 2 .…”