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Atmospheric Chemistry Atmospheric Chemistry István Lagzi Róbert Mészáros Györgyi Gelybó Ádám Leelőssy XML to PDF by RenderX XEP XSL-FO F ormatter, visit us at http://www.renderx.com/ Atmospheric Chemistry by István Lagzi, Róbert Mészáros, Györgyi Gelybó, and Ádám Leelőssy Copyright © 2013 Eötvös Loránd University This book is freely available for research and educational purposes. Reproduction in any form is prohibited without written permission of the owner. Made in the project entitled "E-learning scientific content development in ELTE TTK" with number TÁMOP-4.1.2.A/1-11/1-2011-0073. Consortium leader: Eötvös Loránd University, Consortium Members: ELTE Faculties of Science Student Foundation, ITStudy Hungary Ltd. XML to PDF by RenderX XEP XSL-FO F ormatter, visit us at http://www.renderx.com/ Table of Contents Preface ........................................................................................................................................ vi 1. The structure and composition of the atmosphere .............................................................................. 1 1.1. Formation of the Earth atmosphere ...................................................................................... 1 1.2. A short history of the atmospheric chemistry ......................................................................... 3 1.3. Atmospheric composition .................................................................................................. 4 1.4. Vertical structure of the atmosphere ..................................................................................... 8 1.4.1. Vertical change of composition ................................................................................. 8 1.4.2. Vertical temperature changes .................................................................................... 9 1.5. The planetary boundary layer ............................................................................................ 12 2. Emission of air pollutants ........................................................................................................... 14 2.1. Source types of air pollutants ............................................................................................ 15 2.2. Natural emission sources .................................................................................................. 16 2.2.1. Terrestrial ecosystems ........................................................................................... 16 2.2.2 Aquatic Ecosystems .............................................................................................. 17 2.2.3 Forest fires .......................................................................................................... 17 2.2.4 Volcanic and tectonic activities ................................................................................ 17 2.2.5 Lightning ............................................................................................................ 17 2.3 Anthropogenic emission sources ........................................................................................ 18 2.3.1 Industrial energy production and use ......................................................................... 18 2.3.2. Transport ............................................................................................................ 19 2.3.3 Agriculture .......................................................................................................... 19 2.3.4 Waste management ................................................................................................ 20 2.3.5 Biomass burning ................................................................................................... 20 2.3.6. Anthropogenic sources of air pollutants by different sectors ......................................... 20 3. Basics of the reaction kinetics ...................................................................................................... 26 3.1. Differential rate law ........................................................................................................ 26 3.2. Integrated rate law .......................................................................................................... 27 3.3. Three-body reaction ........................................................................................................ 28 3.4. Photochemical reaction (Photolysis) ................................................................................... 28 3.5. Radicals in the atmosphere ............................................................................................... 29 3.6. Arrhenius Equation ......................................................................................................... 30 3.7. Half-life ........................................................................................................................ 31 3.8. Reaction mechanism ....................................................................................................... 31 3.9. The quasi steady-state approximation (QSSA) ..................................................................... 32 3.10. Application of a reaction mechanism ............................................................................... 33 4. Reactions of air pollutants in the atmosphere .................................................................................. 41 4.1 General notes .................................................................................................................. 41 4.2 Reactions of atmospheric oxygen ....................................................................................... 41 4.3 General reactions in the troposphere and stratosphere ............................................................. 44 5. Biogeochemical cycle of carbon ................................................................................................... 46 5.1. The natural carbon cycle .................................................................................................. 47 5.1.1. Terrestrial processes ............................................................................................. 48 5.1.2. Oceanic processes ............................................................................................... 49 5.1.3 Geological processes ............................................................................................ 52 5.2 Methane ........................................................................................................................ 53 5.2.1 Sources and sinks of atmospheric methane ................................................................. 53 5.3 Human disruption of carbon cycle ...................................................................................... 54 5.4 Carbon cycle research in Hungary ...................................................................................... 58 6. Nitrogen compounds .................................................................................................................. 60 6.1. Nitrogen fixation ............................................................................................................ 61 6.2. Nitrification ................................................................................................................... 62 6.3. Denitrification ............................................................................................................... 63 6.4. Nitrogen deposition ......................................................................................................... 63 6.5. Anthropogenic sources of nitrogen compounds ..................................................................... 64 6.6 Atmospheric reactions of nitrogen species ............................................................................ 65 iii XML to PDF by RenderX XEP XSL-FO F ormatter, visit us at http://www.renderx.com/ Atmospheric Chemistry 7. Sulphur compounds ................................................................................................................... 67 7.1. Sulphur oxides (SOx) ...................................................................................................... 70 7.1.1. Reaction sulphur dioxide in the atmosphere ............................................................... 70 7.2. Hydrogen sulphide (H2S) ................................................................................................. 71 7.3. Carbonyl sulphide (COS) ................................................................................................. 72 7.4 Carbon disulfide (CS2) ..................................................................................................... 72 8. Ozone ..................................................................................................................................... 73 8.1. Stratospheric ozone ......................................................................................................... 73 8.1.1. A short history .................................................................................................... 73 8.1.2. Natural balance of stratospheric ozone ..................................................................... 73 8.1.3. Circulation patterns in the stratosphere ..................................................................... 77 8.1.4. Gas-phase chemistry in the stratosphere .................................................................... 77 8.1.5. Polar ozone chemistry
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