View
232
Download
1
Category
Tags:
Preview:
Citation preview
Weather and Climate
Chapter 3
Factors Affecting Climate
Section 1
The Sun and Latitude•Latitude/Climate Relationship
– Middle and High: distinct seasons– Low: warm all year– Polar: cold all year
•Sun’s Radiant Energy– ½ reflected or absorbed by atmosphere,
½ absorbed by Earth’s surface– Greenhouse effect
•Earth’s air slows rate of heat escape into space
The Sun and Latitude•Global warming: fossil fuel
emissions?– Emissions from fossil fuels’ combustion
produces carbon dioxide– Carbon dioxide absorbs and retains
heat in Earth’s atmosphere– Scientists divided
•Some argue that temp. increased due to human/environment interaction
•Some argue that warming trend is a natural occurrence
– Ample evidence on both sides of the argument…decide for yourself
The Sun and Latitude
The Sun and Latitude
Atmospheric Pressure•Increase in altitude = decrease in pressure
•Heating and cooling of air causes changes in atmospheric pressure– Warm air rises = low pressure– Cooled air drops = high pressure
Atmospheric Pressure•Centers of low pressure, warm air rising (cyclones) = unstable, stormy weather
•Centers of high pressure, cold air dropping = stable, clear, dry weather
Atmospheric Pressure•Four major air pressure zones– Equatorial low– Subtropical highs– Subpolar lows– Polar highs
Global Wind Belts
Prevailing Winds
Global Winds Animation
Global Wind Belts•Prevailing Winds
– Doldrums•Equatorial zone – little to no wind
– NE Trade Winds– Westerlies
•Middle latitudes – west-to-east flow– Polar Easterlies
•Eastward flow from polar to middle latitudes
•Fronts – Two air masses of widely different
temp. or moisture level meet; precipitation results
Global Wind Belts•Jet Stream
–Prevailing winds in upper atmosphere•Up to 300 mph
Oceans and Currents
•Currents moderate the effects of latitude on climate–Water heats and cools more slowly than land
–Landforms near currents experience the currents effects
•Gulf Stream/North Atlantic Drift
Oceans and Currents
Oceans and Currents
Oceans and Currents
•Plymouth, England• http://www.worldclimate.com/cgi-bin/data.pl?
ref=N50W004+1102+03827W
•Kiev, Ukrainehttp://www.worldclimate.com/cgi-bin/data.pl?ref=N50E030+1102+33345W
1
Distributing the Sun’s Heat
Weather Factors
Section 2
Precipitation•Forms of precipitation
– Rain– Snow– Sleet– Hail
•Persistent in low-pressure zones
•Lowest in high-pressure zones
Elevation and MountainsElevation
1,000 ft. increase = 3.5°F decrease or -1°C/100m increase
MountainsOrographic effect
Windward side – high precipitation
Leeward side – rain shadow
Elevation and Mountains
Elevation and Mountains
Frontal Precipitation
Storms
Storms
Storms
Storms
Storms
Climate and Vegetation Patterns
Section 3
Climate and Vegetation•Dry (Arid) Climates
–Arid•Found at about 30° N & S latitude, sometimes on W coasts of continents
•Subtropical high-pressure zone•<10” of annual precip.
–Semiarid•Transition zone between arid and humid regions
•Grain-growing areas (American Great Plains)
Arid & Semiarid
Climate and Vegetation•Middle-Latitude Climates
–Mediterranean•Found on coastal areas of S Europe or W coasts of continents w/cool ocean currents
–Semiarid•Transition zone between arid and humid regions
•Grain-growing areas (American Great Plains)
Recommended