Ozone Project 1, Part 1

Where is the Ozone Layer?

Part 1: Assumptions

We will use oxygen-only chemistry to estimate the ozone layer. Oxygen serves as both a creator and destroyer of ozone. While it is the only element that produces ozone, there are many other elements that destroy ozone. As a result, our model will overestimate the amount of ozone in the atmosphere.

We are using an altitude referencing system in which the earth's surface is defined as 0 km. We are also assuming that the path of the sunlight is perpendicular to the earth's surface. A fairly simple -- but interesting -- project extension allows you to examine the location of the ozone layer if the sunlight approaches through other angular paths.

We are using the Ideal Gas Law in this model, but air is not really an ``ideal'' gas. Ideal gases do not exist in nature, but the Ideal Gas Law is often a sufficiently close approximation to explain the behavior of many real gases.

Since oxygen, O₂, is the only component of air that produces ozone (by photochemical and chemical reactions), our model will center on the O₂ molecule. The O₂ molecule consumes light energy to form ozone, so we will build a model for light intensity (photon flux) as a function of altitude by looking at how the presence of O₂ affects incoming light intensity from the sun.

Although it is fairly obvious that temperature varies with altitude, for the purposes of this project we will assume that temperature remains constant. Specifically, we will assume that the air temperature is 285 degrees Kelvin, which is an estimate of the global average air temperature near the surface of the earth.