17.1 CLIMATE AND ITS CAUSES
Learning Targets
1. Describe the effect of latitude on climate
2. Diagram the Hadley, Ferrell, and Polar atmospheric circulation cells and show how they influence the climate of various locations
3. Discuss position in the global wind belts, proximity to a large water body, position relative to a mountain range
Climate1. Climate is the long-term
average of weather2. Weather is unpredictable3. Climate is predictable
Climate1. Factors influencing region’s
climate:a) Latitudeb) Three Global Wind Beltsc) Prevailing Windsd) Continental Positione) Ocean Currentsf) Altitude
Factor # 1 - Latitude1. The main factor influencing region’s
climate2. Low latitude = high solar energy
a) Equatori. Sun directly overhead; equal night and
day3. High latitude = low solar energy
a) Polesi. Sun at low angle; long days, long nightsii. High albedo
Factor # 2 – Global Wind Belts #1
1. ITCZ – Intertropical Convergence Zone
a)Low Pressure boundary between two Hadley Cells, lots of precipitation.
b)Equator 00 - Doldrums
Factor # 2 – Global Wind Belt #2
1.Hadley and Ferrell Cell Boundarya)High Pressure – sinking cold air
causing evaporationb)Horse latitudes - 300 N/S
Factor # 2 – Global Wind Belt #3
1.Ferrell and Polar Cell Boundarya)Polar jet stream – cold air from
poles meet warmer air from tropics, very stormy
b)500 to 600 N/S latitude
Factor # 3 - Prevailing Winds1. Global wind belts create H and L
zones2. Bring weather from locations
they come from3. H Dry
a) Cold air descending causes evaporation
4. L Weta) Warm air rising and losing its
water
Factor # 4 - Continental Position1. Water regulates air temperature
a) Higher specific heat than land2. Maritime climate – influenced
by nearby large body of watera) Less extreme
3. Continental climate – greater temperature differences between day/night & summer/winter
a) More extreme
Factor # 5 - Ocean Currents1. Surface and deep water currents
affect air temperatures along the coast
2. Cold water moves towards the equator
a) California current cools Southern California
3. Warm water moves towards the poles
a) Gulf stream warms Northern Europe
4. Cold upwelling can cool or heat surrounding land
Factor # 6 - Altitude1. Mountains affect climate by
a) Lowering temperaturei. Temperature decreases with
altitude in the troposphereb) Rainshadow Effect
i. Air is dry after it has been forced over mountains no precipitation
ii. e.g. California compared to Nevada
Top Related