3. Environmental Variation Flashcards
How is the earth divided?
Latitude (parallels E-W)
Longitude (meridians N-S)
What are the 5 latitudinal divisions of the earth?
• Arctic circle (66° N)
• Tropic of Cancer (23° N)
• Equator (0°)
• Tropic of Capricorn (23° S)
• Antarctic circle (66° N)
What degrees of longitude are the north and south poles at?
90° N & 90° S
Define weather
The day-to-day state of our atmosphere
Define climate
Long term averages of weather
What is a solar angle of incidence?
The area solar energy can be dispersed over depending on the latitude of the area
•Equator ~90° solar angle, small surface area, distance between sun and earth is shorter
•Poles ~«90° solar angle, larger surface area, distance between sun and earth is longer
What are the 3 kinds of climate cells?
• Hadley cell
• Ferrel cell
• Polar cell
What latitudes do Hadley cells begin and end at?
0° & 30°
What latitudes do Ferrel cells begin and end at?
30° & 60°
What latitudes do polar cells begin and end at?
60° & 90°
What causes Hadley cells?
Warm, moist air rising at the equator and condensing clouds at about 15 km up. These clouds cause the heavy precipitation in the tropical rainforests. The rising air creates areas of low pressure.
The air is then spreads towards the poles and cools until it decends at about 30° N/S. The air holds less moisture since it is cooler, so it is very dry. The air warms as it reaches the deserts beneath it. Some air returns towards the equator and collect moisture while some moves into the ferrel cells.
The descending air creates areas of high pressure, and helps push air forward in the cycle.
What causes polar cells
Cold, dry air descends over the poles and spreads towards the equator while warming. It rises at around 60° N/S and returns towards the poles.
What causes Ferrel cells?
The strong force from Hadley and polar cells, acting almost like a gear. Air ascends at around 60° N/S and descends at around 30° N/S
What is the Coriolis effect?
The phenomenon that causes fluids and air to curve as they travel across earths surface, because areas under the equator are spinning faster around earths axis than areas at the poles, the momentum is conserved as air/fluid moves away from or towards the equator.
What direction would a storm in the northern hemisphere spin?
counterclockwise
What direction would a storm in the southern hemisphere spin?
clockwise
What direction are winds in the northern hemisphere deflected?
To the right of their direction of travel
What direction are winds in the southern hemisphere deflected?
To the left of their direction of travel
What are winds just north of the equator called?
Northeast tradewinds
What are winds just south of the equator called?
Southeast tradewinds
What are the winds beneath Ferrel cells called?
Westerlies
What are the winds beneath polar cells called?
Polar easterlies
What is a rain shadow?
The phenomenon of relatively less rain falling on the leeward side of a mountain due to the mountain deflecting winds upards on the windward side. The rising air on the windward side cools without advancing poleward and condenses clouds while dry air advances over the mountain.
Results in rainy conditions on the windward side of a mountain and dry conditions on the leeward side
What are gyres?
Horizontally circulating, major water currents in the oceans
Systems of currents spanning across oceans between major land masses
What are the driving forces is gyres?
Winds, the coriolis effect, and position/distance from land masses
