1 – Introduction and Overview

Publisher Summary This chapter provides an overview of the optical properties, composition, and vertical structure of the Earth's atmosphere; the major wind systems; and the climatological-mean distribution of precipitation. The chapter introduces some of the terminology and conventions that will be used in performing calculations involving amounts of mass and rates of movement. The Earth's atmosphere is relatively transparent to incoming solar radiation and opaque to outgoing radiation emitted by the Earth's surface. The blocking of outgoing radiation by the atmosphere, popularly referred to as the “greenhouse effect,” keeps the surface of the Earth warmer than it would be in the absence of an atmosphere. Much of the absorption and reemission of outgoing radiation are due to air molecules, but cloud droplets also play a significant role. The radiation emitted to space by air molecules and cloud droplets provides a basis for remote sensing of the three-dimensional distribution of temperature and various atmospheric constituents using satellite borne sensors. The atmosphere is composed of a mixture of gases in different proportions, where fractional concentration by volume is the same as that based on numbers of molecules, or partial pressures exerted by the gases.