oceanography chapter 7

To produce a surface current of 1.6 knots in the open ocean, a steady wind of _____ knots would be required

80

The arrangement of water masses in the southern Atlantic Ocean from the surface to the bottom is

Antarctic Intermediate Water, North Atlantic Deep Water, Antarctic Bottom Water

Which of the following is a western boundary current?

Brazil Current

what current is part of the South Atlantic Subtropical Gyre

Brazil Current

Which of the following is not an eastern boundary current?

Gulf Stream

mismatched pair

Labrador Current, Humboldt Current

which surface current flows from south to north

Peru Current

which gyre flows in a counterclockwise direction?

South Atlantic Subtropical Gyre

T/F: A Doppler flow meter is a scientific instrument used to measure current flow rates

True

During a strong El Niño event, the news media might be expected to cover

a tropical cyclone in Hawaii or Tahiti

When a meander from the Gulf Stream pinches off and isolates a body of water within the North Atlantic gyre, the body of water is called a

cold core ring

California Current

cold current, northern hemisphere, temperate latitudes

West Wind Drift

cold current, polar latitudes, southern hemisphere

Downwelling can result from

converging surface currents

Thermohaline circulation is driven by

density difference

Deep ocean currents are driven primarily by ________ and modified by ________

density differences; differences in salinity and temperature

T/F: An eastern boundary current is generally narrow and swift

false

T/F: The Gulf Stream moves water away from the equator; the Benguela Current moves some of this same water back toward the equator

false

T/F: Thermohaline circulation is wind-driven

false

T/F:Surface currents affect about 90% of the world's ocean water

false

Which type of current flow moves in a circular path around a subtropical convergence, reflecting Ekman transport, gravity, and the Coriolis effect?

geostrophic circulation

Geostrophic circulation within a gyre driven by

gravity and the Coriolis effect

Deep-water circulation brings dense, cold, oxygen-rich water from the surface to the deep ocean because of

greater dissolution of oxygen in colder water than warmer water

upwelling

movement of water from the bottom to the top of the water column

Ekman transport

net water movement to the left or right of the direction of the wind

Gulf Stream

northern hemisphere, temperate latitudes, warm current

Records indicate that the ocean is warming faster in the Arctic polar regions than elsewhere. If that continues, a possible consequence could be

slowing of deep ocean circulation, resulting in lower oxygen levels in deep water

The El Niño Southern Oscillation can best be described as

the relationship between sea surface temperature and changing atmospheric pressure

T/F: Deep ocean water can be enriched in oxygen when it is mixed with surface water

true

T/F: Deep ocean water masses have characteristic temperatures and salinities

true

T/F: Deep-ocean currents contain water that is high in oxygen

true

T/F: Surface currents form circular patterns in the major ocean basins called "gyres."

true

T/F: The circular movement of surface water currents driven by the major wind belts are called gyres

true

T/F: The five subtropical gyres exhibit geostrophic flow, related to pressure gradients, friction, and the Coriolis effect

true

T/F: The main current in Antarctic waters is the Antarctic Circumpolar Current, also called the West Wind Drift

true

T/F: Two circumpolar currents dominate Antarctica, one current that moves water to the east and one current that moves water to the west

true

T/F: Within the Ekman spiral, deeper water can move in a direction exactly opposite of the wind direction

true

Surface waters are pushed away from land and replaced by nutrient-rich bottom water through

upwelling

Warm core rings and cold core rings are associated with

western boundary currents