Contents -- Preface -- Chapter 1 Introduction and Overview -- 1.1 General Introduction -- 1.2 Basic Properties of the Earth's Atmosphere -- 1.2.1 Thermal structure -- 1.2.2 Composition -- 1.2.3 Energy balance -- 1.3 What is LTE? -- 1.4 Non-LTE Situations -- 1.5 The Importance of Non-LTE -- 1.6 Some Historical Background -- 1.7 Non-LTE Models -- 1.8 Experimental Studies of Non-LTE -- 1.9 Non-LTE in Planetary Atmospheres -- 1.10 References and Further Reading -- Chapter 2 Molecular Spectra -- 2.1 Introduction -- 2.2 Energy Levels in Diatomic Molecules -- 2.2.1 The Born-Oppenheimer approximation -- 2.2.2 Rotation of diatomic molecules -- 2.2.3 Vibrations of diatomic molecules -- 2.2.4 Breakdown of the Born-Oppenheimer approximation -- 2.3 Energy Levels in Polyatomic Molecules -- 2.3.1 General -- 2.3.2 Rotation of polyatomic molecules -- 2.3.3 Vibration of polyatomic molecules -- 2.4 Transitions and Spectral Bands -- 2.4.1 The vibration-rotation band -- 2.4.2 Hot bands -- 2.4.3 Overtone bands -- 2.4.4 Isotope bands -- 2.4.5 Combination bands -- 2.5 Properties of Individual Vibration-Rotation Lines -- 2.5.1 Spectral line strength -- 2.5.2 Widths and shapes of spectral lines -- 2.6 Interactions between Energy Levels -- 2.6.1 Fermi resonance -- 2.6.2 Coriolis interaction -- 2.6.3 Vibration-vibration transfer -- 2.7 References and Further Reading -- Chapter 3 Basic Atmospheric Radiative Transfer -- 3.1 Introduction -- 3.2 Properties of Radiation -- 3.3 The Radiative Transfer Equation -- 3.4 The Formal Solution of the Radiative Transfer Equation -- 3.5 Thermodynamic Equilibrium and Local Thermodynamic Equilibrium -- 3.6 The Source Function in Non-LTE -- 3.6.1 The two-level approach -- 3.6.2 The Einstein relations -- 3.6.3 Radiative processes.

3.6.4 Thermal collisional processes: the statistical equilibrium equation -- 3.6.5 Non-thermal processes -- 3.6.6 The multilevel case -- 3.7 Non-LTE Situations -- 3.7.1 The classical case of non-LTE -- 3.7.2 Non-classical non-LTE situations -- 3.8 References and Further Reading -- Chapter 4 Solutions to the Radiative Transfer Equation in LTE -- 4.1 Introduction -- 4.2 Integration of the Radiative Transfer Equation over Height -- 4.2.1 The RTE in the plane-parallel approach -- 4.2.2 Solar radiation -- 4.2.3 Atmospheric sphericity -- 4.2.4 The radiative equilibrium temperature profile -- 4.2.5 Heating and cooling rates -- 4.2.6 The 'cooling-to-space' approximation -- 4.2.7 The opaque approximation -- 4.3 Integration of the Radiative Transfer Equation over Frequency -- 4.3.1 Special line-by-line integration techniques -- 4.3.2 Spectral band models -- 4.3.3 Independent-line and single-line models -- 4.3.4 Band models with overlapping lines -- 4.3.5 The regular or Elsasser model -- 4.3.6 Random band models -- 4.3.7 Empirical models -- 4.3.8 The 'sum of exponentials' method -- 4.3.9 Inhomogeneous optical paths -- 4.4 Integration of the Radiative Transfer Equation over Solid Angle -- 4.5 References and Further Reading -- Chapter 5 Solutions to the Radiative Transfer Equation in Non-LTE -- 5.1 Introduction -- 5.2 Simple Solutions for Radiative Transfer under Non-LTE -- 5.2.1 Weak radiative field -- 5.2.2 Strong external radiative source -- 5.2.3 Non-thermal collisional and chemical processes -- 5.3 The Full Solution of the Radiative Transfer Equation in Non-LTE -- 5.4 Integration of the RTE in Non-LTE -- 5.4.1 Integrations over frequency and solid angle -- 5.4.2 Integration over altitude -- 5.4.3 Specific non-LTE formulations -- 5.5 Intercomparison of Non-LTE Codes.

5.6 Parameterizations of the Non-LTE Cooling Rate -- 5.7 The Curtis Matrix Method -- 5.8 References and Further Reading -- Chapter 6 Non-LTE Modelling of the Earth's Atmosphere I: CO2 -- 6.1 Introduction -- 6.2 Useful Approximations -- 6.2.1 Induced emission -- 6.2.2 Rotational LTE -- 6.2.3 Resonant levels -- 6.2.4 Line overlapping -- 6.3 Carbon Dioxide CO2 -- 6.3.1 Adoption of a reference atmosphere -- 6.3.2 Boundary layers -- 6.3.3 Radiative processes -- 6.3.4 Collisional processes -- 6.3.5 Solution of the multilevel system -- 6.3.6 Non-LTE populations -- 6.4 References and Further Reading -- Chapter 7 Non-LTE Modelling of the Earth's Atmosphere II: Other Infrared Emitters -- 7.1 Introduction -- 7.2 Carbon Monoxide CO -- 7.2.1 Radiative processes -- 7.2.2 Collisional processes -- 7.2.3 Non-LTE populations -- 7.2.4 Uncertainties in the CO(1) population -- 7.3 Ozone O3 -- 7.3.1 Non-LTE model -- 7.3.2 Chemical recombination -- 7.3.3 Collisional relaxation -- 7.3.4 Other excitation processes -- 7.3.5 Solution of the system -- 7.3.6 Non-LTE populations -- 7.4 Water Vapour H2O -- 7.4.1 Radiative processes -- 7.4.2 Collisional processes -- 7.4.3 Non-LTE populations -- 7.4.4 Uncertainties in the H2O populations -- 7.5 Methane CH4 -- 7.5.1 Radiative processes -- 7.5.2 Collisional processes -- 7.5.3 Non-LTE populations -- 7.5.4 Uncertainties in the CH4 populations -- 7.6 Nitric Oxide NO -- 7.6.1 Radiative processes -- 7.6.2 Collisional relaxation of the rotational and spin states -- 7.6.3 Vibrational-translational collisions and chemical production -- 7.6.4 Non-LTE populations -- 7.7 Nitrogen Dioxide NO2 -- 7.7.1 Excitation and relaxation processes -- 7.7.2 Non-LTE populations -- 7.7.3 Uncertainty in the NO2 populations -- 7.8 Nitrous Oxide N2O -- 7.8.1 Collisional processes -- 7.8.2 Non-LTE populations.

7.8.3 Uncertainties in the N2O populations -- 7.9 Nitric Acid HNO3 -- 7.10 Hydroxyl Radical OH -- 7.11 Molecular Oxygen Atmospheric Infrared Bands -- 7.12 Hydrogen Chloride HC1 and Hydrogen Fluoride HF -- 7.13 NO+ -- 7.14 Atomic Oxygen O(3P) at 63µm -- 7.15 References and Further Reading -- Chapter 8 Remote Sensing of the Non-LTE Atmosphere -- 8.1 Introduction -- 8.2 The Analysis of Emission Measurements -- 8.2.1 Limb observations -- 8.2.2 The limb radiance under optically thin conditions -- 8.2.3 Summary of observations -- 8.3 Observations of Carbon Dioxide in Emission -- 8.3.1 Observations of the CO2 15µm emission -- 8.3.2 Observations of the CO2 10µm emission -- 8.3.3 CO2 4.3µm emission observed by rockets -- 8.3.4 CO2 4.3µm. emission observed by Nimbus 7 SAMS -- 8.3.5 CO2 4.3µm emission observed by UARS ISAMS -- 8.4 Observations of Ozone in Emission -- 8.5 Observations of Water Vapour in Emission -- 8.6 Observations of Carbon Monoxide in Emission -- 8.7 Observations of Nitric Oxide in Emission -- 8.8 Observations of Other Infrared Emissions -- 8.9 Rotational non-LTE -- 8.10 Absorption Measurements -- 8.10.1 The ATMOS experiment -- 8.10.2 CO2 V2 vibrational temperatures -- 8.10.3 CO2 abundance -- 8.11 Simulated Limb Emission Spectra at High Resolution -- 8.12 Simulated Nadir Emission Spectra at High Resolution -- 8.13 Non-LTE Retrieval Schemes -- 8.14 References and Further Reading -- Chapter 9 Cooling and Heating Rates -- 9.1 Introduction -- 9.2 C02 15µm Cooling -- 9.2.1 Cooling rate profiles -- 9.2.2 Global distribution -- 9.3 O3 9.6µm Cooling -- 9.4 H2O 6.3µm Cooling -- 9.5 NO 5.3µm Cooling -- 9.6 O(3P1) 63µm Cooling -- 9.7 Summary of Cooling Rates -- 9.8 CO2 Solar Heating -- 9.8.1 Thermalization of the O(1D) energy -- 9.8.2 Uncertainties in the heating rates -- 9.8.3 Global distribution.

9.9 References and Further Reading -- Chapter 10 Non-LTE in Planetary Atmospheres -- 10.1 Introduction -- 10.2 The Terrestrial Planets: Mars and Venus -- 10.3 A Non-LTE Model for the Martian and Venusian Atmospheres -- 10.3.1 Radiative processes -- 10.3.2 Collisional processes -- 10.4 Mars -- 10.4.1 Reference atmosphere -- 10.4.2 Night-time populations of CO2 and CO -- 10.4.3 Daytime populations -- 10.4.4 Variability and uncertainties in the populations of CO2 -- 10.4.5 Cooling rates -- 10.4.6 Variability and uncertainties in the cooling rates -- 10.4.7 Heating rates -- 10.4.8 Variability and uncertainties in the heating rates -- 10.4.9 Radiative equilibrium temperature -- 10.5 Venus -- 10.5.1 Reference atmosphere -- 10.5.2 Night-time populations of CO2 -- 10.5.3 Daytime populations of CO2 -- 10.5.4 Cooling rates -- 10.5.5 Heating rates -- 10.5.6 Radiative equilibrium temperature -- 10.5.7 Variability and uncertainties -- 10.6 Outer Planets -- 10.7 Titan -- 10.8 Comets -- 10.9 References and Further Reading -- Appendix A List of Symbols Abbreviations and Acronyms -- A.1 List of Symbols -- A.2 List of Abbreviations and Acronyms -- A.3 List of Chemical Species -- Appendix B Physical Constants and Useful Data -- B.1 General and Universal Constants -- B.2 Planetary Characteristics -- Appendix C Terminology and Units -- Appendix D The Planck Function -- Appendix E Conversion Factors and Formulae -- Appendix F CO2 Infrared Bands -- Appendix G O3 Infrared Bands -- Figure Credits -- Bibliography -- Index.