Energetic particle precipitation in ECHAM5/MESSy1 – Part 1: Downward transport of upper atmospheric NO<sub>x</sub> produced by low energy electrons
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Published:2009-04-24
Issue:8
Volume:9
Page:2729-2740
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ISSN:1680-7324
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Container-title:Atmospheric Chemistry and Physics
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language:en
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Short-container-title:Atmos. Chem. Phys.
Author:
Baumgaertner A. J. G.,Jöckel P.,Brühl C.
Abstract
Abstract. The atmospheric chemistry general circulation model ECHAM5/MESSy1 has been extended by processes that parameterise particle precipitation. Several types of particle precipitation that directly affect NOy and HOx concentrations in the middle atmosphere are accounted for and discussed in a series of papers. In the companion paper, the ECHAM5/MESSy1 solar proton event parametrisation is discussed, while in the current paper we focus on low energy electrons (LEE) that produce NOx in the upper atmosphere. For the flux of LEE NOx into the top of the model domain a novel technique which can be applied to most atmospheric chemistry general circulation models has been developed and is presented here. The technique is particularly useful for models with an upper boundary between the stratopause and mesopause and therefore cannot directly incorporate upper atmospheric NOx production. The additional NOx source parametrisation is based on a measure of geomagnetic activity, the Ap index, which has been shown to be a good proxy for LEE NOx interannual variations. HALOE measurements of LEE NOx that has been transported into the stratosphere are used to develop a scaling function which yields a flux of NOx that is applied to the model top. We describe the implementation of the parametrisation as the submodel SPACENOX in ECHAM5/MESSy1 and discuss the results from test simulations. The NOx enhancements are shown to be in good agreement with independent measurements. Ap index data is available for almost one century, thus the parametrisation is suitable for simulations of the recent climate.
Publisher
Copernicus GmbH
Subject
Atmospheric Science
Reference32 articles.
1. Baumgaertner, A. J G., Jöckel, P., Riede, H., Brühl, C., Stiller, G., and Funke, B.: Energetic Particle Precipitation in ECHAM5/MESSy1, Part 2: Solar Proton Events, in preparation, Atmos. Chem. Phys. Discuss., 2009. 2. Brasseur, G P. and Solomon, S.: Aeronomy of the Middle Atmosphere, D. Reidel Publishing Company, 2nd revised edn., 1986. 3. Brühl, C., Steil, B., Stiller, G., Funke, B., and Jöckel, P.: Nitrogen compounds and ozone in the stratosphere: comparison of MIPAS satellite data with the chemistry climate model ECHAM5/MESSy1, Atmos. Chem. Phys., 7, 5585–5598, 2007. 4. Callis, L B. and Lambeth, J D.: NOy formed by precipitating electron events in 1991 and 1992: Descent into the stratosphere as observed by ISAMS, Geophys. Res. Lett., 25, 1875–1878, \\doi10.1029/98GL01219, 1998. 5. Callis, L B., Natarajan, M., Lambeth, J D., and Baker, D N.: Solar - atmospheric coupling by electrons (SOLACE). 2. Calculated stratospheric effects of precipitating electrons, 1979–1988, J. Geophys. Res., 103, 28421–28438, \\doi10.1029/98JD02407, 1998.
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