Difference between weather and climate
Weather- short-term,
day to day conditions
Climate- long-term
average of conditions with extremes
Meteorology- study of the
atmosphere
Air
mass- distinctive body of air (source region defines it as cold, moist,
tropical, etc.) Defined (classified) by moisture
and temperature
(see map on page 213)
Elements
that contribute to the weather:
·
Temperature
·
Air pressure
·
Relative humidity
·
Wind speed and direction
·
Insolation receipt
Four
Atmospheric Lifting Mechanisms (page 215- Figure 8.6):
·
Convergent- air flows
toward an area of low pressure (along ITCZ)
·
Convectional- stimulated by
local surface heating (create afternoon showers)
·
Orographic- air forced
over a barrier (rain shadow- dry side of mountain)
·
Frontal- along leading
edges of contrasting air masses
(check out the graphics on this page for a
good front example:)
http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/af/frnts/home.rxml
Relationship
of cold and warm fronts, squall line, etc.-
Cold
front- cumulonimbus clouds
Warm
front- stratiform/nimbostratus clouds (drizzle)
Squall
line- zone of precipitation in front of a rapidly moving cold front
(may create tornadoes)
Simple
midlatitude cyclonic life cycle (motion) generated by:
1.
pressure gradient force
2.
coriolis force
3.
surface friction
Midlatitude
Cyclone- (wave cyclone) conflict between contrasting air masses, dominate
weather patterns in middle and higher latitudes of Northern and Southern
Hemispheres
Cyclogenesis- atmospheric
process of low pressure system development and strengthening
Data
needed for a daily weather forecast (page 224)
·
Barometric pressure
·
Pressure tendency
·
Surface air temperature
·
Dew-point temperature
·
Wind speed, direction
·
Cloud type and movement
·
Current conditions
·
Sky conditions
·
Visibility
·
Lat precipitation
Violent
weather (ice, lightening, tornado, hurricane, etc.)
Thunderstorms- condensation
of large quantities of water vapor in clouds liberates tremendous amounts of
energy
Develop
under 3 conditions:
1.
Within an air mass (warm, moist air)
2.
Along a cold front
3.
Along areas of orographic lifting
Hail- ice pellets
from a cumulonimbus cloud
Formation
of a Tornado (page 231)- updrafts associated with cumulonimbus clouds,
high altitude winds, surface friction slowing lower altitude winds which causes
a rotation between high and low altitude wind speeds.
Important: map on page 233, Figure 8.26- See
Weather
Climate
Air mass
Convectional lifting
Rain shadow
Cold and warm front
Squall line
Cyclogenesis
Stationary front
Lightning
Storm surge