Saturday, April 17, 2010

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.




Friday, April 9, 2010

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.

Friday, April 2, 2010

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.