Marine Science Unit 9 Test

During a warm-phase ENSO event, warm water _____. This event causes _______

accumulates in the Eastern Pacific, dramatic weather changes

Without currents, the world's climate would be

more extreme

Ocean Conveyor Belt

the interconnected surface and deep water currents that redistribute heat throughout the world

Deep circulation is water movement caused by

the mixing of water masses of different water densities

Ekman Spiral

the spiral of water layer flowing to the right of the layer above in the Northern Hemisphere and to the left of the layer above in the Southern Hemisphere

Draw a circle on the area of low pressure and a square on the area of high pressure in the Pacific Ocean before an El Niño event

Circle - Indonesia Square - South America

How many gyres are there? Where are they?

5 gyres (North and south pacific, North and South Atlantic, and Indian)

Draw a circle on the area of low pressure and a square on the area of high pressure in the Pacific Ocean during an El Niño event.

Circle - middle of the Pacific ocean Squares - Indonesia and South America

Why are western ocean boundary currents faster than eastern ocean boundary currents?

Coriolis effect is stronger in higher latitudes and trade winds push water west

What makes downwelling occur?

Density gradients

Although different water layers move in different directions in an Ekman spiral, the overall effect of Ekman transport is to move a current directly in line with the wind.

False

Both upwelling and downwelling can result from a wind parallel to shore.

True

The circular flow in each ocean basin is called a gyre

True

The general pattern of deep water circulation begins with dense water sinking. If flows along the bottom, mixes with other water, rises and warms, and eventually becomes part of a surface current.

True

Western boundary currents flow more quickly than eastern boundary currents partly because the trade winds pile water on the western ocean boundary.

True

Thermocline

a steep temperature gradient in a body of water such as an ocean, marked by a layer above and below which the water is at different temperatures

The primary force that provide energy for surface currents include

Wind

What makes upwelling occur?

Wind blowing parallel to shore pushes surface water out to sea due to Eckman transport

What forces are responsible for currents?

Wind, change in sea level, and variations in water density

Downwelling

a downward vertical flow current that pushes surface water deeper into the ocean

Based on density stratification, the primary water mass classifications include

central water, intermediate water, and deep water

ENSO

characterized by the buildup of high pressure in the Western Pacific and low pressure on the east; trade winds weaken, and upwelling along the South American coast

A countercurrent is a _____. An undercurrent is a _______.

current that runs in the opposite direction of an adjacent current, current that runs in the opposite direction and beneath a surface current

There are _____ gyres and one is found in _______.

five, north atlantic

Trade Winds

flow westward between 30° latitude and the equator

Gyres are called ______ currents. They tend to flow _________

geostrophic, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere

The primary source of deep and bottom water is form

high latitude, where freezing and cooling cause an increase in salinity and density

Upwelling

is an upward vertical flow current that brings deep water to the surface

The ocean conveyor belt is important because

it redistributes heat and moderates Earth's temperature

Eddies

large circular loops that break away from currents; caused by friction from the flow of a current

Currents tend to flow around the periphery of an ocean basin because

of the elevated surface level in the center and the Coriolis effect

An undercurrent runs ____ an adjacent current. The reason why if forms is ______.

perpendicular to, unclear

Gyre

the circular flow of currents in an ocean basin due to the Coriolis effect

Coriolis Effect

the tendency for the path of an object moving in the North Hemisphere to deflect to the right, or to deflect left when moving in the Southern Hemisphere