TOPIC 2: ENVIROMENTAL HETEROGENITY Flashcards
Climate
Long term average pattern of weather, on a local, regional, or global scale
- average pattern of temp
Weather
Is the combination of temperature, humidity, precipitation, wind, cloudiness, etc
at a specific place and time
- short term
How does solar radiation contribute to climate?
drives all of the differences in climate across the earth
The ability to sustain life on our planet is due to?
the sun- main source of energy
What is the main source of energy on Earth? How much reaches the surface?
The sun
Only 51% reaches the surface and is absorbed
• Rest is reflected, scattered, or absorbed by the atmosphere
• Absorbed energy is remitted as heat
Explain the Greenhouse effect
crucial in maintaining the surface warmth
* without it we wouldn’t have life
gases in the atmosphere, such as carbon dioxide, trap heat similar to the glass roof of a greenhouse. These heat-trapping gases are called greenhouse gases.
During the day, the Sun shines through the atmosphere. Earth’s surface warms up in the sunlight. At night, Earth’s surface cools, releasing heat back into the air. But some of the heat is trapped by the greenhouse gases in the atmosphere. That’s what keeps our Earth a warm and cozy 58 degrees Fahrenheit (14 degrees Celsius), on average
What varies the amount of solar energy intercepted by the earth?
latitude
• Decreases towards the poles
• Increases towards the equator
• The angle
• Depth of atmosphere
(1) at higher latitudes, radiation hits the surface at a steeper angle, spreading light over more area, and (2) radiation penetrating the atmosphere at a steeper angle travels through more air and encounters more atmospheric particles, which reflect more of it back into space
Explain how uplift occurs
Warm air rises in the tropics creating a low pressure system
* hot air rises b/c less dense more energy than cooler air
Condenses into clouds and precipitates
Cooling air forced North and South
Subsidence
cooling air from the tropics meets air moving southward from the pole
air moves back to the Earth’s surface when temperature gradient equalizes
*opposite of uplift ; there is no warmer air to rise over cold air it all the same energy/ temp so instead of the air rising it sinks to earths surface meaning there is no condensation and no precipitation either so its drier in those area
Hadley Cell
(0-30⁰) Tropical
Formed from the uplift at the equator
Polar Cell
(60-90⁰) Polar
Formed from subsidence of air at the poles
Ferrell Cell
(30-60⁰) Temperate
Circulates air between and closes off the other cells
driven by movement of the hadley and polar cells
What do cell formation determine?
Determines general levels of precipitation
Wind Currents
• Atmospheric circulation linked to wind currents
- rapid movement of air
Corliolis Effect
= apparent deflection of wind currents from Earth’s perspective
The effect of Earth’s rotation on the direction of winds and currents
Ocean Currents
Global winds create ocean currents
are the main thermal conveyors of the planet
Describe how ocean currents tend to move?
tend to move clockwise in the northern hemisphere and counter clockwise in
the southern hemisphere
• Warm currents tend to move from the tropics outwards while cool currents
originate from the polar regions
What are the 3 major influences that alter global temperature patterns?
1) Distribution of land and water
2) Elevation
3) Earth’s orbit around the sun
Distribution of Land and Water
• Type of vegetation cover of land influences heat uptake
Albedo
= amount of solar radiation that a surface reflects
• Internal continental areas are less affected by the heating and cooling of ocean currents
Where is precipitation tend to be higher and why?
Precipitation tends to be higher in the southern hemisphere relative to the north
• Larger surface area of water cover
There is much more water cover (more ocean) which means there is more evaporation and precipitation
What determines whether a particular region will be tropical forest grassy plain or barren landscape?
Location; where a region is on the earth relative to the sun
What parts of the earth receive the least solar radiation?
The North and South Poles
Where does subsidence occur?
Areas where this occurs are often dry (ie. deserts)
Subsidence also occurs at the poles where air is dry
