Chemical reaction pathways affecting stratospheric and mesospheric ozone
| Autor: | Peter Mieth, Ralph Lehmann, Ulrike Langematz, Benedikt Steil, J. Lee Grenfell |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Atmospheric Science
Ozone 010504 meteorology & atmospheric sciences Soil Science Aquatic Science Oceanography Atmospheric sciences 7. Clean energy 01 natural sciences Mesosphere Troposphere Atmosphere chemistry.chemical_compound Geochemistry and Petrology 0103 physical sciences Earth and Planetary Sciences (miscellaneous) 010303 astronomy & astrophysics Stratosphere NOx 0105 earth and related environmental sciences Earth-Surface Processes Water Science and Technology Null cycle Ecology Photodissociation Paleontology Forestry Geophysics chemistry 13. Climate action Space and Planetary Science Climatology Environmental science |
| Zdroj: | Journal of Geophysical Research. 111 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/2004jd005713 |
| Popis: | Catalytic cycles and other chemical pathways affecting ozone are normally estimated empirically in atmospheric models. In this work we have automatically quantified such processes by applying a newly developed analysis package called the Pathway Analysis Program (PAP). It used modeled chemical rates and concentrations as input. These were supplied by the Module Efficiently Calculating the Chemistry of the Atmosphere MECCA box model, itself initialized by the Free University of Berlin Climate Middle Atmosphere Model with Chemistry. We analyzed equatorial, midlatitude and high-latitude locations over 24-hour periods during spring in both hemispheres. We present results for locations in the lower stratosphere, upper stratosphere and midmesosphere. Oxygen photolysis dominated (>99%) in situ ozone production in the equatorial lower stratosphere, in the upper stratosphere and in the mesosphere. In the lower stratosphere midlatitudes the ozone smog cycle (already established in the troposphere) rivaled oxygen photolysis as an in situ ozone source in both hemispheres. However, absolute ozone production rates in midlatitudes were rather slow compared with at the equator, typically 1650 ppt ozone/day. In the equatorial lower stratosphere, five catalytic sinks were important (each contributing at least 5% to chemical ozone loss): a HOx cycle, a HOBr cycle and its HOCl analog, a water-HOx cycle and a mixed chlorine-bromine cycle. Important in midlatitudes were the HOx cycle, a NOx cycle, the HOBr cycle and the mixed chlorine-bromine cycle. In lower-stratosphere high latitudes, the chlorine dimer cycle and the mixed chlorine-bromine cycle dominated in both hemispheres. A variant on the latter, involving BrCl formation, also featured. In the upper stratosphere high latitudes (where strong negative ozone trends are observed), a nitrogen cycle, a chlorine cycle, and a mixed chlorine-nitrogen cycle were found. In the mesosphere, three closely related HOx cycles dominated ozone loss. |
| Databáze: | OpenAIRE |
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