Lecture 2: Environmental Heterogeneity Flashcards
(32 cards)
Describe Climate
The long term average pattern of weather, on a local, regional, or global scale
Describe weather
weather is the combination of temperature, humidity, precipitation, wind, etc. at a specific place and time
What powers the climate system?
Solar radiation
The differences in climate across the earth are primarily driven by what
Solar radiation
The ability to sustain life on our planet is due to what
The sun
What is the main source of energy
the sun
How much of the suns energy reaches the surface and is absorbed
51%
What happens to the energy from the sun that is not absorbed
reflected, scattered or absorbed by the atmosphere
What is crucial in maintaining the surface warmth
The greenhouse effect
The amount of solar energy intercepted by the earth varies by
Latitude
Angle
Depth of atmosphere
The amount of solar energy intercepted by the earth ______ towards the poles and _____ towards the equator
Decreases
Increases
Describe Uplift
1) Warm air rises in the tropics that creates a low pressure system
2) Condenses into clouds and precipitates
3) Cooling air forced North and South
4) Cooling air from the tropics eventually meets air moving southward from the poles
Describe Subsidence
1) Air moves back to the Earth’s surface when temperature gradient equalizes
2) Areas where this occurs are often very dry (Deserts) or at the poles where the air is very dry
What three cells (describe them too) determines the general levels of precipitation
1) Hadley cell
- 0 to 30 degree latitude (Tropical)
- Formed from the uplift at the equator
2) Polar Cell
- 60 to 90 degrees latitude (Polar)
- Formed from subsidence of air at the poles
3) Ferrell Cell
- 30 to 60 degrees latitude (Temperate)
- Circulates air between and closes off the other cells
Describe Winnipeg’s weather in terms of distinct cell formation
At 55 degrees but we often feel the polar jet because were that close to 60 degrees latitude
Atmospheric circulation is linked to what
Wind currents
Describe the Corliolis Effect
IT is the apparent deflection of wind currents from the Earth’s perceptive
Moves to the right in the northern hemisphere
Moves to the left in the southern hemispher
Give an example of the Corliolis effect
When flushing a toilet in the northern hemisphere the water will circle to the right and left in the southern hemisphere
if there are no jets
If looking at wind from space, what direction would it go
Directly North to south
What creates ocean currents
Global winds
Describe the way currents tend to move in the two hemispheres
Clockwise in the northern hemisphere
Counterclockwise in southern hemisphere
What are the main thermal conveyors of the planet
Ocean currents
Why and what hemisphere typically has more precipitation
Southern over northern because there is much more water
What are the three major influences that alter global temperatures pattern and why
1) Distribution of land and water
- Water is a better heat sink than land cause it retains heat longer
- Type of vegetation cover influences heat uptake
- Topography can create rain shadows
2) Elevation
- Air temperature decreases with elevation
3) Earths orbit around the sun
