EARTH SCIENCE > ATMOSPHERE > ATMOSPHERIC WINDS > BOUNDARY LAYER WINDS
1. The layer of fluid near a boundary that is affected by friction against that
boundary surface, and possibly by transport of heat and other variables (such
as winds) across that surface.
In meteorology, this is the atmospheric boundary layer. 2. In a physical or
mathematical system, a region over which some property or term in the equations
varies rapidly, that is, over its full range; conversely, a region outside of
which certain terms may be neglected.
American Meteorological Society Glossary of Meteorology Online: