Several types of chemical models are used by our group to estimate the effects of atmospheric trace gases on the chemical composition of the troposphere. One-dimensional models study the vertical interactions and distributions of chemical constituents. Point models determine a single snapshot in time and space of the atmospheric chemical composition. These are often used to analyze in-situ field data in which only a few atmospheric trace gases are actually measured, as they can fill in some of the missing atmospheric chemical constituents and provide a more complete picture of the atmospheric makeup. Box models determine an overall general chemical composition of the troposphere by treating the vertical distribution as a single cell.