Oceanography Chap 9
How long does an ENSO event typically last? 1 month 6 months 1 year 3 years 6 years
1 year
How much of the water in the world ocean is involved in surface currents? 1% 10% 20% 50% 90%
10%
What is the residence time of most deep waters? 1 to 10 years 50 to 100 years 200 to 300 years 500 to 1000 years over 1 million years
200 to 300 years
What describes the theoretical direction of Ekman transport in the Southern Hemisphere? 30° to the left of wind direction 45° to the left of wind direction 45° to the right of wind direction 90° to the left of wind direction 90° to the right of wind direction
90 to the left of wind direction
What water mass is the densest in the world ocean? Arctic Bottom Water North Atlantic Bottom Water North Pacific Bottom Water Equatorial Bottom Water Antarctic Bottom Water
Antarctic Bottom Water
An eastern boundary current Kuroshio Current West Wind Drift Cromwell Current Benguela Current Peru Current
Benguela Current
The boundary between which two water masses in tropical latitudes is the most pronounced and abrupt? Surface water and central water Central water and intermediate water Intermediate water and deep water Intermediate water and bottom water Deep water and bottom water
Central water and intermediate water
Which is an example of coastal upwelling affecting weather onshore? Cold water is transported away from the shore causing abnormally high temperatures. Southerly winds bring warm temperatures and dry weather. Cold water is brought to the surface that chills the air above, inducing cool, wet weather. A warm-water pool accumulates and warm moist air rises, inducing rainfall. Dry, cold air is transported from the north, inducing drought conditions.
Cold water is brought to the surface that chills the air above, inducing cool, wet weather.
An undercurrent Kuroshio Current West Wind Drift Cromwell Current Benguela Current Peru Current
Cromwell Current
_____ currents flow equatorward and are shallow and broad. Polar Counter Western boundary Eastern boundary Transverse
Eastern boundary
The "hill" of water that occurs as a result of westward intensification due to the Coriolis effect is formed by _____. cold-core eddies warm-core eddies Ekman transport transverse currents countercurrents
Ekman transport
Downwelling can have direct effects on the climate of an adjacent coast. True False
False
During major ENSO events, sea level rises in the western Pacific and water temperatures also increase. True False
False
Langmuir circulation consists of slowly twisting cells of windows, or convergences where seaweed, debris, and foam accumulate, that operates in the surface layer, as well as below the pycnocline. True False
False
Surface currents flow vertically in the uppermost 400 meters of the water column. True False
False
The Ekman spiral is similar to an eddy in that the water spirals downward like a whirlpool. True False
False
The Pacific's Equatorial Currents are driven eastward by westerly winds and flow faster than the westward flowing currents driven by the trades. True False
False
Western boundary currents move cold water poleward in each of the gyres. True False
False
What is true about the Coriolis effect? It is absent at the equator. It is strongest near the equator. It causes cold-core eddies in the Northern Hemisphere to rotate clockwise. It causes Northern Hemisphere surface currents to flow to the left of the wind direction. It causes the peak of the "hill" in the center of the gyre to be steeper on the eastern side.
It is absent at the equator.
A western boundary current Kuroshio Current West Wind Drift Cromwell Current Benguela Current Peru Current
Kuroshio Current
What is true of density, salinity, and temperature? Water masses of the same density will not combine. Only one combination of temperature and salinity can yield a given density. Many combinations of temperature and salinity can yield the same density. Density of water tends to decrease with depth. Both temperature and salinity decrease with depth.
Many combinations of temperature and salinity can yield the same density.
What water mass is the most saline in the world ocean? Antarctic Bottom Water Northern Atlantic Deep Water Northern Pacific Deep Water Mediterranean Deep Water Arctic Bottom Water
Mediterranean Deep Water
Equatorial upwelling occurs worldwide, but where is it most pronounced? Atlantic Ocean Southern Ocean Indian Ocean Pacific Ocean Arctic Ocean
Pacific Ocean
Current that slows during ENSO events Kuroshio Current West Wind Drift Cromwell Current Benguela Current Peru Current
Peru Current
Who was the first to record the observation of currents? Pytheas Japanese fishermen Sir John Murray Klaus Wyrtki James Cook
Pytheas
Equatorial upwelling occurs in what current? Gulf Stream Brazil Current North Atlantic Current California Current South Equatorial Current
South Equatorial Current
What changes are caused by the Southern Oscillation in the Pacific Ocean? Trade winds blow from east to west. Low pressure builds in the western Pacific. Trade winds blow from west to east. High pressure builds in the eastern Pacific. Equatorial currents move faster.
Trade winds blow from west to east.
Countercurrents are also known as undercurrents. True False
True
During a non-El Niño year, the air and surface water flow westward to the western Pacific, the thermocline rises, and upwelling of cold water occurs along the west coast of Central and South America. True False
True
Gyres tend to collect seaweed and trash as their centers. True False
True
Sir John Murray observed that the temperature of the ocean's surface water was almost always higher than the temperature of deep water. True False
True
Surface currents distribute tropical heat worldwide. The winters in Scotland, Ireland, and England are relatively mild due to the energy transported by the North Atlantic Current and the Gulf Stream. True False
True
The North Atlantic Intermediate Water and the Antarctic Intermediate Water are both produced by caballing. True False
True
The westward intensification is driven by the Coriolis effect. True False
True
Recent research suggests that warm- and cold-core eddies may be responsible for slowly moving abyssal storms, which leave ripple marks in deep sediments. True False
True
What can be caused by ENSO events in the eastern Pacific? Productivity increases due to high nutrient upwelling. Water temperatures decrease. Drought conditions occur. Water levels decrease. Upwelled water is nutrient-depleted, causing loss of productivity.
Upwelled water is nutrient-depleted, causing loss of productivity.
Wind-induced vertical circulation is also known as ____. Ekman transport Eddy formation Undercurrent formation Langmuir circulation Upwelling/downwelling
Upwelling/downwelling
What is the largest current? North Atlantic gyre South Atlantic gyre West Wind Drift Indian Ocean gyre North Pacific gyre
West Wind Drift
The centers of gyres tend to be ____. high energy with high productivity high energy with high salinity and little productivity calm and support high productivity calm and support relatively little life high energy with strong winds and storms
calm and support relatively little life
What current is associated with upwelling? countercurrents eastern boundary currents western boundary currents warm-water currents transverse currents
eastern boundary currents
The flow of water around the periphery of an ocean basin driven by winds and the Coriolis effect is called a(n) ____. easterly trade wind gyre eddy westerly
gyre
Langmuir circulation occurs only ____. at the equator in the top 20 meters of water below 100 meters of water at deep-ocean depths below the pycnocline
in the top 20 meters of water
The transport of heat and energy by surface currents throughout the ocean can have influences on climate and weather. Where does the greatest amount of heat transfer by surface currents occur? Antarctic mid-latitudes equator arctic ITCZ
mid-latitudes
Which currents are the slow, deep currents that affect seawater beneath the pycnocline? deep-ocean thermocline surface thermohaline turbidity
thermohaline
The trade winds and westerlies drive what geostrophic currents? eastern boundary currents western boundary currents countercurrents polar currents transverse currents
transverse currents
The Gulf Stream is the largest of what type of current? polar currents countercurrents eastern boundary currents transverse currents western boundary currents
western boundary currents
The fastest and deepest geostrophic currents are ____. eastern boundary currents western boundary currents cold-water currents transverse currents countercurrents
western boundary currents
What currents carry the highest volume of water? eastern boundary currents western boundary currents countercurrents polar currents transverse currents
western boundary currents
Surface currents are driven mainly by ____. deep-ocean movements density differences salinity differences temperature differences wind friction
wind friction
A transverse current Kuroshio Current West Wind Drift Cromwell Current Benguela Current Peru Current
West Wind Drift
