Radiative Transfer

If you are following this primer on infrared spectroscopy and global warming you already have some of the basics of radiative transfer.  The previous post in this series develops a simple multi-layer model of the carbon dioxide in the troposphere.  It leaves out many important features but shows conceptually how absorption and emission behave in layers of the troposphere.

The current post is intended to wrap up the topic and touch upon a few issues that were not discussed. It is possible to teach a year-long course in radiative transfer (or even multiple courses); so of course this post does not do the topic justice, but perhaps it provides some basic principles that give the reader a cursory understanding of the topic.

A Multi-Layer Model of Carbon Dioxide

I have put together a simple multi-layer model of  carbon dioxide in the troposphere.  It is based upon the same principles as the two-layer model and the three-layer model.  It accounts for the temperature and pressure profiles from the  previous post and it is part of a primer on infrared spectroscopy and global warming.  Just like those other models there are still caveats; this model is intended to be illustrative of concepts and therefore it is conceptually simple.

A Three-Layer Model

This post is part of a primer on infrared spectroscopy and global warming. The previous post introduces a two-layer model  and is a necessary prerequisite to understanding this post.  In this post I start with the following assumptions.  There is a source of infrared radiance that has emissivity of 1, i.e., it radiates as a perfect blackbody at a temperature of  288 K.  The radiance from that layer is I₀

There is a layer of air 1000 m thick with 380 ppm carbon dioxide at a temperature of 278 K.  There is another layer of air 1000 m thick with 380 ppm carbon dioxide at 268 K.  All layers are at a constant pressure of one atmosphere.

A Two-Layer Model

This post is part of a primer on infrared spectroscopy and global warming. The previous post discusses the issue of saturation in the 14-micron band of carbon dioxide in a single-layer model.   The post before that discusses Beer's Law, and is a necessary prerequisite to understanding this post.  This post starts to look beyond the single-layer model, by discussing a two-layer model, and beginning a discussion of radiative transfer.

A Note On Saturation of the Carbon Dioxide 15-micron Band

This post is part of a primer on infrared spectroscopy and global warming. The previous post discusses Beer's Law, and is a necessary prerequisite to understanding this post.  The previous post also introduced the idea of saturation of a single layer model.  This post looks more deeply at the single-layer model and the saturation of the 15-micron band of carbon dioxide.

Infrared Spectra of Molecules of Interest

This post is part of a primer on infrared spectroscopy and global warming. The previous post concludes a three-post series that looks at molecules and radiation and discusses how molecules give rise to infrared spectra.  This post discusses the infrared spectra of some molecules of interest.

 Figure Source