home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
The Epic Interactive Encyclopedia 1998
/
Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
/
F
/
Front
/
INFOTEXT
< prev
Wrap
Text File
|
1992-09-03
|
853b
|
21 lines
In meteorology, the interface between two air
masses of different temperature or humidity.
A cold front marks the line of advance of a
cold air mass from below, as it displaces a
warm air mass; a warm front marks the advance
of a warm air mass pushing a cold one
forward. Warm air, being lighter, tends to
rise above the cold; its moisture is carried
upwards and usually falls as rain or snow,
hence the changeable weather conditions at
fronts. Fronts are rarely stable and move
with the air mass. An occluded front is a
composite form, where a cold front overtakes
a warm front, lifting warm air above the
Earth's surface. An inversion occurs when the
normal properties get reversed; this happens
when a layer of air traps another near the
surface, preventing the normal rising of
surface air. Warm temperatures and
pollination result from inversions.