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
Name the 3 types of cells
Hadley, Ferrel and Polar
What direction is the wind moving in the Northern Hemisphere according to coriolis effect?
• To the right in Northern Hemisphere
What direction is the wind moving in the southern Hemisphere according to coriolis effect
To the left in Southern Hemisphere
What direction would the wind move if viewed from space?
north- south
What obstructs the ocean currents?
Continents act as obstructions to the water currents
What is a better heat sink, water or land?
• Water is a better heat sink than land and retains heat longer
What is a rain shadow?
• Topography (mountains) can create rain shadows
- dry region on the leeward side of mtn caused by precipitation at upper altitudes
- windward supports denser vegetation and diff species leeward= desert
- as air rises it cools and loses moisture on the windward side
- descending dry air picks up moisture on leeward side
Why are deep continental areas very dry?
• Deep continental areas become very dry due to long distance from water bodies meaning little evaporation and precipitation
How does elevation impact temperature?
air temp decreases with elevation
* warming effect of earths surface decreases with elevation
There is a much higher pressure at the surface, meaning molecules of air are closely packed together and they move faster. Higher speed means more heat
- lower pressure with elevation lowers the speed of the molecules= low temp
What is the cause of seasons on Earth?
The tilt of the Earth’s axis as it rotates around the Sun
What months is the Northern Hemisphere tilted towards the Sun?
May to August (Summmer)
What months is the Northern Hemisphere tilted away from the Sun?
November to February (Winter)
The seasons are ___________ for the Southern Hemisphere
Reversed
Seasons are restricted to _____________ zones
Temperate
What areas have extreme day/night cycles?
Due to the tilt of the earth, Polar areas
Tropical areas experience a ________________________ cycle
Due to the tilt of the earth, these areas will experience a shift in the Intertropical Convergence Zone (ITCZ) and experience wet dry cycle
Intertropical Convergence Zone (ITCZ)
The latitude that receives the most intense sunlight, which causes the ascending branches of the two Hadley cells to converge
-Experience wet dry cycles.
Environmental Heterogeneity
This term describes the fact that weather patterns differ at different spatial scales.
Global -> Regional -> Local -> Micro
What do global and regional climate patterns determine?
Large-scale distribution of plants and animals
Why do Local Climatic conditions not match the general climate profiles of the larger region?
Actual environment can differ as the climate profile is just a generalization
microclimate
Climate within a small area that differs significantly from the climate of the surrounding area.
-The conditions actually experienced by organisms.
-Our focus.
Where is precipitation the highest?
the equator and decreases as you move north and south
