Geo 101 Ch.3 El Nino
Food Web
A community of organisms where there are several interrelated food chains
El Niño/Southern Oscillation (ENSO)
Changes in oceanic and atmospheric current patterns that move warm Pacific Ocean surface water farther east than normal, resulting in worldwide changes in weather.
During an El Niño year, how does weather change in the western Pacific?
El Niño causes higher rainfall in parts of North and South America and drought in western Pacific nations such as Australia and Indonesia.
Explain how cold ocean currents off a coast produce dry conditions on nearby land.
Ocean currents act much like a conveyer belt, transporting warm water and precipitation from the equator toward the poles and cold water from the poles back to the tropics. Thus, currents regulate global climate, helping to counteract the uneven distribution of solar radiation reaching Earth's surface.
What drives the 3-D, conveyor-belt ocean currents?
Winds drive ocean currents in the upper 100 meters of the ocean's surface. ... These deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline circulation.
Gyre
the large circular currents in the ocean
Upwelling
when water is floating up in the ocean
Downwelling
when water is flowing down in the ocean
Westerlies
wind flowing from subtropical highs towards the poles in both hemisphere that is deflected by coriolis
Gulf Stream
A warm ocean current that flows from the Gulf of Mexico northward through the Atlantic Ocean
Trade winds
Air flowing towards the equator
What is a gyre, and what creates one in every ocean basin?
An ocean gyre is a large system of circular ocean currents formed by global wind patterns and forces created by Earth's rotation. The movement of the world's major ocean gyres helps drive the "ocean conveyor belt."
Ocean surface currents
Currents that move on or near the surface of the ocean and are driven by winds and uneven heating of earth's atmosphere.
What happens to upwelling off the coast of Peru and Chile during an El Niño year? How does this affect the lives and economics of these countries?
During an El Niño event, westward-blowing trade winds weaken along the Equator. These changes in air pressure and wind speed cause warm surface water to move eastward along the Equator, from the western Pacific to the coast of northern South America
Explain how ocean currents help redistribute heat energy around the world.
Like atmospheric circulation, ocean currents help to redistribute energy across the earth. Because they cover 67% of the earth's surface, the oceans receive 67% of the sun's energy that reaches earth. ... In total, ocean currents transfer about 25% of the global heat budget.
During an El Niño year, how does weather change along the central coast of South America?
The effects of El Niño in South America are direct and stronger than in North America. An El Niño is associated with warm and very wet weather months in April-October along the coasts of northern Peru and Ecuador, causing major flooding whenever the event is strong or extreme.
During a "normal" year, what kind of weather conditions are found in the western Pacific Indonesia, Malaysia)?
Though El Niño is a normal climate pattern that develops every 3-7 years, it can cause unusual weather patterns around the globe. In general, El Niño causes higher rainfall in parts of North and South America and drought in western Pacific nations such as Australia and Indonesia.
Plankton
Tiny algae and animals that float in water and are carried by waves and currents.
Walker Circulation
circulation cells within the equatorial atmosphere caused by differences in climate
Which is denser and will sink, colder water or warmer water?
colder water
What determines the speed and direction of surface ocean currents?
driven by wind and reflect average wind conditions
Ocean deep circulation (3-D)
move more slowly than surface currents moved by thermohaline circrclation moves large volumes of water
Which is denser and will sink, salty water or fresh water?
salty water will sink
