Biosphere (2) Flashcards
Why is wind an important abiotic factor to terrestrial organisms?
-Wind increases an organism’s rate of water loss by evaporation.
-The resulting increase in evaporative cooling can be advantageous on a hot summer day, but it can cause dangerous wind chill in the winter.
Why is fire considered an abiotic factor?
Fire occurs frequently enough that many plants have adapted to this disturbance.
Regional climate influences the distribution of terrestrial communities. What causes climatic variations? Explain the case for coastal climate and rainfall.
Most climatic variations are due to the uneven heating of Earth’s surface as it orbits the sun, setting up patterns of precipitation and prevailing winds.
-Ocean currents influence coastal climate.
-Landforms such as mountains affect rainfall.
Why does Earth receive an uneven distribution of solar energy?
Because of its curvature, Earth receives an uneven distribution of solar energy.
The sun’s rays strike equatorial areas most directly.Away from the equator, the rays strike Earth’s surface at a slant.
How would oceans or lands near the equator be affected by this uneven solar energy?
The same amount of solar energy is spread over a larger area due to the curvature of the earth.
Thus, any particular area of land or ocean near the equator absorbs more heat than comparable areas in the northern or southern latitudes.
What is the explanation for seasons?
The seasons of the year result from the permanent tilt of the planet on its axis as it orbits the sun.
Which region experiences the greatest annual input and least seasonal variation?
The tropics experience the greatest annual input and least seasonal variation in solar radiation
Where are distinct seasonal variations prevalent?
Distinct seasonal variation occurs in the temperate zones, the latitudes between the tropics and the Arctic Circle in the north and the Antarctic Circle in the south
Explain how intense solar radiation near the equator affects global patterns of rainfall.
High temperatures in the tropics evaporate water and cause warm, moist air to rise and flow toward the poles.
As the rising air cools, its ability to hold moisture diminishes. The water vapor condenses into clouds and rain falls.
This explains why rainforests are located near the equator.
How are desert areas created?
After losing its moisture over equatorial zones, air spreads away from the equator until it cools and descends again at latitudes of about 30° north and south.
This descending dry air absorbs moisture from the land, creating desert areas.
What are prevailing winds and how are they caused?
Prevailing winds are major global air movements.
Result from the combined effects of the rising and falling of air masses and Earth’s rotation.
How does the earth’s spinning affect the winds in the tropical and temperate regions?
In the tropics, Earth’s rapidly moving surface deflects vertically circulating air, making the trade winds blow from east to west.
In temperate zones, the slower-moving surface produces the westerlies, winds that blow from west to east.
How are ocean currents created?
A combination of the prevailing winds, the planet’s rotation, unequal heating of surface waters, and the locations and shapes of the continents creates ocean currents, and river-like flow patterns at the oceans’ surface.
Ocean currents have a profound effect on regional climates. Explain.
The Gulf Stream circulates warm water northward from the Gulf of Mexico and makes the climate on the west coast of Great Britain warmer during winter than the coast of New England, which is cooled by the Labrador Current flowing south from the coast of Greenland.
How do landforms affect the climate?
As moist air moves in off the water and encounters the mountains, it flows upward, cools at higher altitudes, and drops a large amount of water.
Farther inland, precipitation increases again as the air moves up and over higher mountains
