Boundary Layer Definition
and Scale
Definition:

- The earth's surface is the lower boundary on the atmospheric domain and
hence, interacts with the lower part of the earth's atmosphere
- The Boundary Layer can be defined as: "that
part of the troposphere that is directly influenced by the presence of the
earth's surface and responds to surface forcings with a time
scale of about an hour or less."
Scale:
- Boundary layer depth is variable, however, it is typically between
100-3000 m deep (see Fig. 1.1)
- Note that the tropospheric depth is on one order of magnitude greater that
boundary layer depth
- ratio of tropospheric depth to radius of earth: 10 km/6400 km = 0.001
or .1%
- ratio of boundary layer depth to radius of earth: 1 km/6400 km =
0.0001 or 0.01% !!!!!!