Sensitivity of simulated mesospheric transport of nitrogen oxides to parameterized gravity waves
| Autor: | Elisa Manzini, Katharina Meraner, Bernd Funke, Angela Gardini, Hauke Schmidt |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Atmospheric Science
Momentum (technical analysis) 010504 meteorology & atmospheric sciences Meteorology Sudden stratospheric warming 010502 geochemistry & geophysics Atmospheric sciences 01 natural sciences Mesosphere Atmosphere Geophysics Altitude Space and Planetary Science Stratopause Physics::Space Physics Earth and Planetary Sciences (miscellaneous) Astrophysics::Earth and Planetary Astrophysics Gravity wave Physics::Atmospheric and Oceanic Physics NOx 0105 earth and related environmental sciences |
| Zdroj: | Journal of Geophysical Research: Atmospheres. 121:12-12,061 |
| ISSN: | 2169-897X |
| DOI: | 10.1002/2016jd025012 |
| Popis: | Gravity waves strongly influence the circulation and transport processes in the middle atmosphere. We analyze the sensitivity of the simulated mesospheric transport of nitrogen oxides (NOx) to differences in a parameterization of non-orographic gravity waves. After particularly strong sudden stratospheric warming (SSW) events as in January 2009, satellite instruments measured a strong mesospheric descent of NOx. However, this downward transport is in general underestimated in models covering this altitude range. We use simulations of the atmospheric general circulation and chemistry model HAMMONIA (Hamburg Model of Neutral and Ionized Atmosphere) to discuss both differences in a homogeneous background gravity wave source and a source related to frontal activity. The results show that the transport of NOx is highly sensitive to such differences. With a stronger gravity wave source, less NOx is transported after the SSW to the mesosphere and the elevated stratopause descends more rapidly to its climatological altitude. We observe the opposite by weakening the gravity wave sources yielding a better agreement with the observations. The amount of the transported NOx is controlled by the altitude at which momentum is deposited in the atmosphere. The higher the altitude where the momentum is deposited in the upper mesosphere, the stronger is the descent of NOx. A small wave amplitude favors the transition to turbulence at a higher altitude due to the exponential increase of the amplitude with height. |
| Databáze: | OpenAIRE |
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