Download Frontal Systems - LunsfordEnvironmentalScience

Frontal Systems
&
High and Low Pressure
Science 10
Frontal Systems
 Fronts are created when one air mass
overtakes another
 They will typically be classified into two
categories:
– Warm front – when warm air runs into cold air
– Cold front – when cold air runs into warm air
Warm Front
Warm Front
 The warm air gradually climbs over the colder air
 Typical clouds associated with a warm front are:
–
–
–
–
–
Cirrus
Cirrostratus
Altostratus
Nimbostratus
Stratus
 Associated with periods of steady precipitation
 May exist over 50-100km
Cold Front
Cold Front
 Occurs when warm air is violently pushed
up by advancing cold air
 Cumulus clouds are associated with a cold
front
 Can result in cumulonimbus clouds
 Short periods of heavy precipitation
 Covers a small geographical area (2-5km)
Weather Map
High Pressure
 High pressure has
“more” air above it
 It is pulled down by
gravity
 Due to Coriolis Effect,
it spins clockwise and
out in the Northern
Hemisphere
 Clear skies
 Light winds
Low Pressure
 Low pressure has “less”
air above it
 Air from a high pressure
flows towards a low
pressure
 Due to Coriolis Effect, it
spins counter clockwise
and in in the Northern
Hemisphere
 Clouds
 Strong winds
High and Low Pressures
Questions Pg. 32 9-12
Pg. 34 13-16
Pg. 32
9. Spherical Earth makes
Sun’s more or less
concentrated.
10. Air Mass- a very large mass of air that has nearly uniform
properties such as temperature, humidity, and pressure.
-arctic (cold, dry)
- continental polar (cool, dry)
- continental tropical (hot, dry)
- maritime polar (cool, humid)
- maritime tropical (hot, humid)
11.
12. Coriolis Effect
Pg. 34
13. Jet streams are fast flowing, narrow air currents found in
the atmosphere, usually between the Troposphere and the
Stratosphere.
14. A Front is a zone that develops as a result of the meeting
of two air masses with different characteristics.
15. A Stationary Front- is when two air masses meet but neither
advances.
16. When cold air replaces warm air we have a Cold Front.
Cold fronts usually bring short periods of heavy precipitation.