ENVIRSC 1C03 Lecture Notes - Lecture 14: Solar Irradiance, Humid Continental Climate, Subtropics
Document Summary
An air mass is an extremely large body of air whose temperature and humidity are uniform both horizontally and vertically. The areas of the globe where air masses form are called source regions. Large bodies of air must remain over a source region for a substantial length of time for an air mass to form. Air masses affect vast areas and their temperature and humidity characteristics will reflect that of the source region. Air masses are classified by their origin in terms of latitude and surface type. These characteristics are categorized using a lowercase letter for the surface type and an upper case letter for the latitude. The latitude indicates the temperature of the air mass whereas the surface type indicates the moisture content. A source region is an area from which an air mass originates and usually has a flat and uniform composition and light surface winds.