Atmospheric Radiation

Professor James Coakley received his degrees in Physics: B.S. (1968) UCLA, and MA (1970) and PhD (1972) Berkeley. He entered the atmospheric sciences in 1972 as a Postdoctoral Fellow in the Advanced Study Program at the National Center for Atmospheric Research (NCAR) and stayed at NCAR in various staff scientist positions until moving to Oregon State University in 1988 where he is currently a Professor of Atmospheric Sciences in the College of Oceanic and Atmospheric Sciences. His research focuses on the problem of climate change and in particular on the remote sensing of aerosol and cloud properties from satellites, and the effects of aerosols and clouds on the Earth's energy budget and climate. Dr. Coakley is a Fellow of the American Meteorological Society and the American Association for the Advancement of Science. He has served on editorial advisory board for Tellus, as an Associate Editor for the Journal of Geophysical Research, and as Editor for the Journal of Climate. He has also served on various panels for the National Research Council and as a member for two of the Council's standing committees: Meteorological Analysis, Prediction, and Research and Climate Research. Professor Ping Yang received the B.S. (theoretical physics) and M.S. (atmospheric physics) degrees from Lanzhou, China, in 1985 and 1988, respectively, and the Ph.D. degree in meteorology from the University of Utah, Salt Lake City, USA, in 1995. He is currently a professor and the holder of the David Bullock Harris Chair in Geosciences, the Department of Atmospheric Sciences, Texas A&M University, College Station, Texas, USA. His research interests cover the areas of remote sensing and radiative transfer. He has been actively conducting research in the modeling of the optical and radiative properties of clouds and aerosols, in particular, cirrus clouds, and their applications to space-borne and ground-based remote sensing. He has co-authored more than 160 peer-reviewed publications. He received a best paper award from the Climate and Radiation Branch, NASA Goddard Space Center in 2000, the U.S. National Science Foundation CAREER award in 2003, and the Dean's Distinguished Achievement Award for Faculty Research, College of Geosciences, Texas A&M University in 2004. He is a member of the MODIS Science Team and. He currently serves as an associate editor for the Journal of Atmospheric Sciences, the Journal of Quantitative Spectroscopy & Radiative Transfer, and the Journal of Applied Meteorology and Climatology.

• Preface ix1 The Earth’s Energy Budget and Climate Change 11.1 Introduction 11.2 Radiative Heating of the Atmosphere 21.3 Global Energy Budget 31.4 The Window-Gray Approximation and the Greenhouse Effect 61.5 Climate Sensitivity and Climate Feedbacks 81.6 Radiative Time Constant 121.7 Composition of the Earth’s Atmosphere 141.8 Radiation and the Earth’s Mean Temperature Profile 191.9 The Spatial Distribution of Radiative Heating and Circulation 321.10 Summary and Outlook 35References 392 Radiation and Its Sources 412.1 Light as an Electromagnetic Wave 412.2 Radiation from an Oscillating Dipole, Radiance, and Radiative Flux 422.3 Radiometry 472.4 Blackbody Radiation: Light as a Photon 502.5 Incident Sunlight 57References 633 Transfer of Radiation in the Earth’s Atmosphere 653.1 Cross Sections 653.2 Scattering Cross Section and Scattering Phase Function 683.3 Elementary Principles of Light Scattering 713.4 Equation of Radiative Transfer 773.5 Radiative Transfer Equations for Solar and Terrestrial Radiation 80References 824 Solutions to the Equation of Radiative Transfer 854.1 Introduction 854.2 Formal Solution to the Equation of Radiative Transfer 864.3 Solution for Thermal Emission 884.4 Infrared Fluxes and Heating Rates 934.5 Formal Solution for Scattering and Absorption 1024.6 Single Scattering Approximation 1034.7 Fourier Decomposition of the Radiative Transfer Equation 1104.8 The Legendre Series Representation and the Eddington Approximation 1124.9 Adding Layers in the Eddington Approximation 1214.10 Adding a Surface with a Nonzero Albedo in the Eddington Approximation 1234.11 Clouds in the Thermal Infrared 1244.12 Optional Separation of Direct and Diffuse Radiances 1264.13 Optional Separating the Diffusely Scattered Light from the Direct Beam in the Eddington and Two-Stream Approximations 1274.14 Optional The δ-Eddington Approximation 1304.15 Optional The Discrete Ordinate Method and DISORT 1354.16 Optional Adding-Doubling Method 1384.17 Optional Monte Carlo Simulations 140References 1465 Treatment of Molecular Absorption in the Atmosphere 1495.1 Spectrally Averaged Transmissions 1495.2 Molecular Absorption Spectra 1515.3 Positions and Strengths of Absorption Lines within Vibration-Rotation Bands 1555.4 Shapes of Absorption Lines 1595.5 Doppler Broadening and the Voigt Line Shape 1625.6 Average Absorptivity for a Single, Weak Absorption Line 1635.7 Average Absorptivity for a Single, Strong, Pressure-Broadened Absorption Line 1645.8 Treatment of Inhomogeneous Atmospheric Paths 1665.9 Average Transmissivities for Bands of Nonoverlapping Absorption Lines 1695.10 Approximate Treatments of Average Transmissivities for Overlapping Lines 1715.11 Exponential Sum-Fit and Correlated k-Distribution Methods 1775.12 Treatment of Overlapping Molecular Absorption Bands 182References 1846 Absorption of Solar Radiation by the Earth’s Atmosphere and Surface 1856.1 Introduction 1856.2 Absorption of UV and Visible Sunlight by Ozone 1866.3 Absorption of Sunlight by Water Vapor 191References 2017 Simplified Estimates of Emission 2037.1 Introduction 2037.2 Emission in the 15 μmBandofCO2 2037.3 Change in Emitted Flux due to Doubling of CO2 2097.4 Changes in Stratospheric Emission and Temperature Caused by a Doubling of CO2 2137.5 Afterthoughts 215References 217Appendix A Useful Physical and Geophysical Constants 219Appendix B Solving Differential Equations 221B. 1 Simple Integration 221B. 2 Integration Factor 221B. 3 Second Order Differential Equations 223Appendix C Integrals of the Planck Function 225Appendix D Random Model Summations of Absorption Line Parameters for the Infrared Bands of Carbon Dioxide 227Reference 229Appendix E Ultraviolet and Visible Absorption Cross Sections of Ozone 231References 231Index 233