Local winds
Air absorbs very little heat from the sun's rays. It is indirectly heated by contact with
warm surfaces. It also relies on contact with cooling surfaces to lose heat.
A local, anabatic wind can be set up by air rising up a slope warmed by the morning
sun.
The same slope may cool the air at night causing it to flow down hill to form a
katabatic wind. To maintain coverage, loudspeaker cluster tilts may need to be
readjusted between morning orchestral rehearsals for a major outdoor event and the
actual show.
Gusts and squalls
On a fair day when the ground is warm and clouds are forming and being moved by a
very light breeze, local winds may vary in direction and strength as illustrated below.
All material © 2007. Martin Audio Ltd. Subject to change without notice.