Comparison of model results transporting the odd nitrogen family with results transporting separate odd nitrogen species

Abstract

We have developed a fast two-dimensional residual circulation stratospheric model. In order to calculate possible effects of long-term changes for trace gases for a large number of scenarios and to examine the model sensitivities to dynamical and photochemical assumptions and inputs, the model is designed to minimize computer requirements. The species continuity equations are solved using process splitting, that is, by successively applying the operators associated with advective changes with photochemical and diffusive forcing. The first study undertaken with this model concerns family chemistry approximations, in which groups of species are related by photochemical equilibrium assumptions and transported as one species.

Middle atmospheric changes caused by the January and March 2012 solar proton events

“…This model was first discussed over 20 yr ago (Douglass et al, 1989;Jackman et al, 1990) and has undergone extensive improvements over the years (e.g., Considine et al, 1994;Jackman et al, 1996;Fleming et al, 1999Fleming et al, , 2007Fleming et al, , 2011. The vertical range of the model, equally spaced in log pressure, is from the ground to approximately 92 km (0.0024 hPa) with a 1 km grid spacing.…”

Stratospheric Ozone Variations Caused by Solar Proton Events Between 1963 and 2005

“…The model has been in use since the late 1980's and has undergone extensive improvements over the years (Douglas et al, 1989;Jackman et al, 1990). The vertical range of the model, equally spaced in log pressure, is from the ground to approximately 90 km (0.0024 hPa) with approximately a 2 km grid spacing.…”

Technical note: Evaluation of the simultaneous measurements of mesospheric OH, HO<sub>2</sub>, and O<sub>3</sub> under a photochemical equilibrium assumption – a statistical approach

“…For our calculations we used the global 3-D chemical transport model (CTM) of the middle atmosphere developed by the Leibniz Institute of Atmospheric Physics (IAP; e.g., Berger, 1994;Ebel et al, 1995;Kremp et al, 1999;Berger and von Zahn, 1999;Hartogh et al, 2004Hartogh et al, , 2011Sonnemann et al, 1998Sonnemann et al, , 2006Sonnemann et al, , 2007. It was designed particularly for investigation of the spatio-temporal structure of phenomena in the MLT region and specifically in the extended mesopause region.…”

“…In 3-D chemical transport models that include a large set of physical and chemical processes with a broad spectrum of spatio-temporal scales. In particular, the chemical family concept is widely used for simulating gas-phase photochemistry of the lower and middle atmosphere (e.g., Douglass et al, 1989;Kaye and Rood, 1989;Rasch et al, 1995), when transport is taken into account only for the concentration of a chemical family, while relative concentrations of the constituent fast components are calculated from the instantaneous stable equilibrium condition. Complemented with Henry's law (e.g., Djouad et al, 2003;Tulet et al, 2006) in multiphase models, this approach markedly saves calculation time and increases the overall stability of the numerical scheme.…”