Exoplanet Atmospheres: Physical Processes

by Sara Seager

Overview

Over the past twenty years, astronomers have identified hundreds of extrasolar planets--planets orbiting stars other than the sun. Recent research in this burgeoning field has made it possible to observe and measure the atmospheres of these exoplanets. This is the first textbook to describe the basic physical processes--including radiative transfer, molecular absorption, and chemical processes--common to all planetary atmospheres, as well as the transit, eclipse, and thermal phase variation observations that are unique to exoplanets.


In each chapter, Sara Seager offers a conceptual introduction, examples that combine the relevant physics equations with real data, and exercises. Topics range from foundational knowledge, such as the origin of atmospheric composition and planetary spectra, to more advanced concepts, such as solutions to the radiative transfer equation, polarization, and molecular and condensate opacities. Since planets vary widely in their atmospheric properties, Seager emphasizes the major physical processes that govern all planetary atmospheres.


Moving from first principles to cutting-edge research, Exoplanet Atmospheres is an ideal resource for students and researchers in astronomy and earth sciences, one that will help prepare them for the next generation of planetary science.

• The first textbook to describe exoplanet atmospheres


• Illustrates concepts using examples grounded in real data


• Provides a step-by-step guide to understanding the structure and emergent spectrum of a planetary atmosphere


• Includes exercises for students

Product Details

ISBN-13:	9781400835300
Publisher:	Princeton University Press
Publication date:	08/02/2010
Series:	Princeton Series in Astrophysics , #18
Sold by:	Barnes & Noble
Format:	eBook
Pages:	264
File size:	8 MB

About the Author

Sara Seager is professor of planetary science and physics at the Massachusetts Institute of Technology.

Table of Contents

Preface xi
Chapter 1: Introduction 1
1.1 Exoplanets from Afar 1
1.2 Two Paths to Observing Exoplanet Atmospheres 2
1.3 Types of Planets 4


Chapter 2: Intensity and Flux 9
2.1 Introduction 9
2.2 Intensity 9
2.3 Flux and Other Intensity Moments 10
2.4 Surface Flux 11
2.5 Observed Flux 14
2.6 Luminosity and Outgoing Energy 16
2.7 Incident Flux and Incident Energy 17
2.8 Black Body Intensity and Black Body Flux 19
2.9 Lambert Surface 20
2.10 Summary 22


Chapter 3: Temperature, Albedos, and Flux Ratios 25
3.1 Introduction 25
3.2 Energy Balance 25
3.3 Planetary Temperatures 27
3.4 Planetary Albedos 32
3.5 Planet-Star Flux Ratios 40
3.6 Planetary Phase Curves 45
3.7 Summary 47


Chapter 4: Composition of a Planetary Atmosphere 51
4.1 Introduction 51
4.2 Composition of Earth's and Jupiter's Atmospheres 51
4.3 Chemical Composition 56
4.4 Basic Cloud Physics 66
4.5 Atmospheric Escape 72
4.6 Atmospheric Evolution 81
4.7 Summary 83


Chapter 5: Radiative Transfer I: Fundamentals 87
5.1 Introduction 87
5.2 Opacity 87
5.3 Optical Depth 91
5.4 Local Thermodynamic Equilibrium 93
5.5 The Source Function 96
5.6 The Equation of Radiative Transfer 96
5.7 Summary 100


Chapter 6: Radiative Transfer II: Solutions 103
6.1 Introduction 103
6.2 A Conceptual Description of the Emergent Spectrum 103
6.3 An Introduction to Line Formation 108
6.4 Approximate Solutions to the Plane-Parallel Radiative Transfer Equation 113
6.5 Monte Carlo Radiative Transfer 125
6.6 Summary 127


Chapter 7: Polarization 133
7.1 Introduction 133
7.2 Description of Polarized Radiation 134
7.3 Polarization Calculations 138
7.4 Polarization from Planets 140
7.5 Summary 143


Chapter 8: Opacities 145
8.1 Introduction 145
8.2 Energy Levels in Atoms and Molecules 146
8.3 Molecular Absorption Cross Sections 161
8.4 Rayleigh Scattering 166
8.5 Condensate Opacities 167
8.6 Summary 176


Chapter 9: Vertical Thermal Structure of a Planetary Atmosphere 181
9.1 Introduction 181
9.2 Earth's Vertical Atmospheric Structure 181
9.3 Hydrostatic Equilibrium and the Pressure Scale Height 183
9.4 Surface Temperature for a Simplified Atmosphere 186
9.5 Convection versus Radiation 190
9.6 The Radiative Equilibrium Temperature Profile 192
9.7 The Adiabatic Temperature Profile 200
9.8 The One-Dimensional Temperature-Pressure Profile 202
9.9 Temperature Retrieval 205
9.10 Summary 207
10.Atmospheric Circulation 211
10.1 Introduction 211
10.2 Radiative and Advective Timescales 213
10.3 Large-Scale Flow and Patterns 215
10.4 Atmospheric Dynamics Equations 218
10.5 Connection to Observations 223
10.6 Summary 225
11.Atmospheric Biosignatures 229
11.1 Introduction 229
11.2 Earth's Biosignatures 229
11.3 The Ideal Biosignature Gas 230
11.4 Prospects 231
11.5 Summary 234
A. Planetary Data 237
Index 241

What People are Saying About This

Mark Marley

This book fills an important gap between astronomy and planetary science. I am quite sure it will become the standard text for any course covering exoplanet atmospheres.
— Mark Marley, NASA Ames Research Center

Turner

Exoplanet Atmospheres is a major scholarly contribution to an exciting, scientifically important, and rapidly expanding area of research in astrophysics, written by one of its intellectual leaders. Seager pulls together a comprehensive and meticulously organized set of scientific results and techniques. This book will be a bible for students and professionals interested in exoplanet atmospheres.
— Edwin L. Turner, Princeton University

From the Publisher

"This book fills an important gap between astronomy and planetary science. I am quite sure it will become the standard text for any course covering exoplanet atmospheres."—Mark Marley, NASA Ames Research Center

"Exoplanet Atmospheres is a major scholarly contribution to an exciting, scientifically important, and rapidly expanding area of research in astrophysics, written by one of its intellectual leaders. Seager pulls together a comprehensive and meticulously organized set of scientific results and techniques. This book will be a bible for students and professionals interested in exoplanet atmospheres."—Edwin L. Turner, Princeton University

Editorial Reviews

"The author, an acknowledged leader in the field, has written a text intended for advanced undergraduates, graduate students, and professional astronomers. The book is organized topically, and could easily be used alone or as part of a more general course in thermodynamics or radiation astrophysics. . . . This is an excellent resource. . . . The author's clear explanations are easy to follow."—-April S. Whitt, Planetarian

"As a basic textbook for an introductory course in atmospheric physics for undergraduates this book is fine; it's nicely and clearly written and includes model exam questions."—-F. W. Taylor, Observatory

"The book will certainly provide a useful starting point for what I suspect will be the increasing number of scientists wishing to work on the physics of exoplanets."—-Jonathan Tennyson, Contemporary Physics

From the Publisher

"Seager provides an excellent contribution to the Princeton Series in Astrophysics, which will appeal to graduate students and working professionals in astronomy."

Choice

The book will certainly provide a useful starting point for what I suspect will be the increasing number of scientists wishing to work on the physics of exoplanets.

Contemporary Physics - Jonathan Tennyson

As a basic textbook for an introductory course in atmospheric physics for undergraduates this book is fine; it's nicely and clearly written and includes model exam questions.

Observatory - F. W. Taylor

The author, an acknowledged leader in the field, has written a text intended for advanced undergraduates, graduate students, and professional astronomers. The book is organized topically, and could easily be used alone or as part of a more general course in thermodynamics or radiation astrophysics. . . . This is an excellent resource. . . . The author's clear explanations are easy to follow.

Planetarian - April S. Whitt

As a basic textbook for an introductory course in atmospheric physics for undergraduates this book is fine; it's nicely and clearly written and includes model exam questions.

Observatory - F.W. Taylor

The book will certainly provide a useful starting point for what I suspect will be the increasing number of scientists wishing to work on the physics of exoplanets.
— Jonathan Tennyson

Contemporary Physics

As a basic textbook for an introductory course in atmospheric physics for undergraduates this book is fine; it's nicely and clearly written and includes model exam questions.
— F. W. Taylor

Observatory

The author, an acknowledged leader in the field, has written a text intended for advanced undergraduates, graduate students, and professional astronomers. The book is organized topically, and could easily be used alone or as part of a more general course in thermodynamics or radiation astrophysics. . . . This is an excellent resource. . . . The author's clear explanations are easy to follow.
— April S. Whitt

Planetarian