Accession Number : ADA311245

Title :   The Lowest Atmosphere: Atmospheric Boundary Layer Including Atmospheric Surface Layer.

Descriptive Note : Final rept. May 94-Nov 95,

Corporate Author : INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA

Personal Author(s) : Bauer, Ernest

PDF Url : ADA311245

Report Date : APR 1996

Pagination or Media Count : 67

Abstract : The Atmospheric Boundary Layer (ABL) is the lowest portion of the Earth's atmosphere which is affected significantly by the properties of the Earth's (land or ocean) surface. The ABL may show a large daily variation in wind, temperature, and stability or turbulence. The ABL is typically 0.5-1 km deep, representing roughly 10 percent of the total mass of the atmosphere. The lowest 10 percent of the ABL, or 50-150 m elevation, is called the Atmospheric Surface Layer (ASL); this is the region we live in, and some of its characteristics are important for a variety of applications. This document provides the basic physics background for applications such as the spreading of tracer clouds in the atmosphere, forest fires, optical refraction near the surface (mirages), etc. It is becoming customary to use the term Atmospheric (vs. Planetary) Boundary Layer (and Surface Layer) to distinguish from the comparable Oceanic Layers. Note that the top of the ABL is normally placed at 0.5-1 km, which is appropriate for mid-latitude conditions. However, at some low-latitude locations, such as the Persian Gulf or central Texas, the top of the ABL frequently reaches 3-4 km in the daytime in summer.

Descriptors :   *GEOSTROPHIC WIND, *EARTH ATMOSPHERE, PRESSURE GRADIENTS, OCEAN SURFACE, ATMOSPHERIC TEMPERATURE, BOUNDARY LAYER, TEMPERATURE GRADIENTS, CLIMATE, WIND DIRECTION, CLEAR AIR TURBULENCE, WIND VELOCITY, SOLAR RADIATION, BAROMETRIC PRESSURE, AIR WATER INTERACTIONS, WIND STRESS, AIR MASS ANALYSIS, CONVECTION(ATMOSPHERIC), THUNDERSTORMS, JET STREAMS, HURRICANES.

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE