1 -- INTRODUCTION

A number of characteristics can be used to describe Earth's atmosphere. These include temperature, pressure, and chemical composition as well as physical and chemical processes. In this lecture, we will explore these topics. The atmosphere also has a complicated, multi-faceted dynamical structure involving horizontal and vertical motions of the air. While a detailed exploration of this structure is made in Lecture 6, a general overview of the "general circulation" pattern is presented in this lecture. We study these varied aspects of temperature, pressure, chemical composition, and general circulation because all are responsible for the observed distribution of stratospheric ozone.

1.1 Lecture Objectives

When you complete the reading of this discussion you should be able to understand

• the chemical composition of the atmosphere and categorization of atmospheric components, with emphasis on the trace constituents
• the role of temperature, pressure, and density in atmospheric studies
• the vertical structure of Earth's atmosphere and how it relates to temperature changes with height
• seasonal and latitudinal variations in temperature, both at the surface and higher up
• characteristics of the zonal wind
• effects of temporal atmospheric variations such as El Nino-Southern Oscillation on ozone levels
• relationship of atmospheric dynamics to geostrophic balance (geostrophic and thermal winds) and conserved quantities (potential temperature and vorticity)
• types of waves in the atmosphere.