Ch 17 HW

The index that compares SST in the eastern and western Pacific is called the ___.

PDO index

The switch from the warm phase to the cold phase in the Pacific Ocean or from the cold phase to the warm phase is called the ___.

Pacific Decadal Oscillation (PDO)

Why do equatorial regions tend to have warmer ocean waters but lower-than-average salinities?

They are subjected to warm atmospheric temperatures but high rainfall.

The regions in the ocean where surface-water temperatures are consistently higher than adjacent regions and that form and re-form from year to year are called ___.

warm pools

Identify the factors that lead to the formation of oceanic warm pools.

Release of latent heat Excess insolation

ENSO stand for El ___ Southern ____.

Nino Oscillation

Why do substances such as salts dissolve in water?

The polar nature of the bonds in water attracts atoms bonded in other molecules, sometimes enough to break them apart.

What effect does the polar nature of water molecules have on solid materials placed in water?

The positive and negative sides of a water molecule attract charged ions in the solids, which potentially can break them apart.

What are ocean gyres?

The series of interacting circular surface currents in the ocean

Which of the following changes are likely to take place in the cold phase (La Niña) of ENSO?

The southern U.S. becomes much drier. The central and eastern equatorial Pacific experiences reduced rainfall. The western Pacific experiences more precipitation.

Select all the statements below that accurately compared SST data from July and January in the Atlantic Ocean.

The southernmost waters of the Atlantic will be colder in July than in January. The northernmost waters of the Atlantic will be warmer in July than in January.

Identify conditions associated with the warm phase (El Niño) of ENSO.

The thermocline in the western Pacific becomes shallower. Rainfall over the central Pacific is increased.

Warm pools can set up ___.

an east-west circuit of air through the tropics

The equator-to-pole decrease in the amount of ___ received is the main reason there is a general equator-to-pole decrease in SST.

insolation

Warm pools in the tropics form due to ___.

latent heat stored in the subtropics being released in rising air over the tropics

The rising air near the equator and the mid-latitudes tends to result in ___ saline water than areas in the subtropics and polar regions that experience descending air. This is because rising air leads to increased levels of ___.

less; precipitation

Areas of the ocean in upwelling zones, near continents, and in shallow seas tend to have relatively high levels of biological production because ___.

nutrients levels are high

How do SST patterns in the Atlantic change from July to January? The warmest SST shift to the ___.

south

The thermocline, in the ocean, is the zone between ___.

warmer upper waters and the colder deeper waters

Assuming everything else is equal, rank the water masses with the following temperatures by their densities. (Place the temperature resulting in the lowest density at the top.)

1. 15c 2.10 c 3. 2 c 4. 4c

A water mass at ___°C will have the greatest density (assuming all the salinities are the same.)

4

Identify surface water circulation patterns commonly found in the western Pacific.

A clockwise gyre exists in the northwestern Pacific water near Japan. Water flows westward near the equator.

What is the major surface-water circulation in the Indian Ocean?

A counterclockwise gyre south of the equator

What is the surface water circulation pattern in the northern Atlantic Ocean?

A large subtropical gyre exists that flows clockwise in the Atlantic.

What defining change occurs in the Pacific Decadal Oscillation (PDO)?

A switch between the warm and cool phase of SST occurs in the eastern Pacific.

What are the major components of the southern subtropical gyre in the Indian Ocean?

A west-flowing segment along the equator A warm, south-flowing Mozambique current east of Africa A cool, north-flowing Western Australian current

Which areas listed below generally have the highest levels of productivity in the ocean?

Areas of active upwelling Areas along the edge of continents and in shallow seas

Which of the following statements about the formation of ice in the ocean is true?

As sea ice forms the salt is excluded from the ice. As sea ice forms the water around the ice becomes more saline.

Which of the following statements best describes the link between the depth of the thermocline in the equatorial Pacific and ENSO events?

ENSO events drive changes in the depth of the thermocline.

How are the ENSO effects in the equatorial Pacific spread to higher latitudes?

By Hadley cell circulation

Which of these is the center of a warm pool located in the western Atlantic?

Caribbean Sea

Match the marine biozone to its description.

Coastal (intertidal zone) - Organisms are challenged by water availability, wave action, temperature variations, and changes in substrate. Biodiversity is higher in rocky substrates than in shifting sand. Sea grass, crabs, starfish, and plankton are abundant. Pelagic zone - Located seaward of the low-tide mark and contains vast open waters. The zone is subdivided by depth and the amount of light received. Aphotic zone - Organisms are adapted to low temperatures and low oxygen content. Food enters the zone from above as biological matter falls into the zone as marine "snow." Benthic zone - A diverse set of habits that all exist at the sea bottom. Organisms live on or in the seafloor. The zone is poorly explored.

What is the impact of continents and other landmasses on the east-west connections in oceans?

Continents cause ocean currents to turn north or south and results in upwelling along coasts.

What is the primary reason ocean circulation runs to the north or south?

Continents interrupt the east-west flow, forcing water to move north or south.

Which of the following accurately describe coral reefs?

Coral reefs are sensitive to environmental change, pollution, overfishing, and other disturbances. Coral reefs tend to occur in shallow and relatively warm surface waters.

How does the density of water change as salinity increases? (Assume everything else stays the same.)

Density increases.

El Niño (warm), normal (neutral), and La Niña are the three phases of ___ as determined by surface water temperatures in the eastern equatorial Pacific.

ENSO

Match the winds to their description.

Easterlies - Blow from the poles toward the equator and from the east to the west Westerlies - Blow poleward from the horse latitudes (30ο) and from the west to the east Trade winds - Blow toward the equator and from the east to the west

The change in direction of water flow from the ocean's surface to the null point as shown here is the ____ spiral.

Ekman

When warm water from the western Pacific moves eastward and replaces the cold waters off the coast of South America, ___ occurs. The warm water limits upwelling and causes changes to the local ecosystem and weather patterns across Earth.

El Niño

ENSO includes phenomena linked with ___.

El Niño Southern Oscillation

Rank the phases of ENSO in terms of SST in the equatorial eastern Pacific. (Place the phase with the highest SST in the eastern Pacific at the top.)

El Niño Neutral La Niña

True or false: Salinity and temperature decrease in a rather simple linear fashion with increasing depth in the ocean.

False

Select the correct summary of global surface winds.

From 30ο latitude, winds blow toward the equator and 60ο latitude, and winds blow toward 60ο latitude from the poles and from lower latitudes.

What is the name used for the series of interacting circular surface currents in the ocean?

Gyres

Which of the following zones are aphotic?

Hadal Mesopelagic Deep sea

How does air pressure typically change in the Northern Hemisphere during an El Niño event?

Higher than normal pressure is centered on Hudson Bay, the northcentral Pacific, southwestern Europe, and western Africa. Lower than normal pressure forms over the eastern Pacific, Mexico, and the southern U.S.

What is the bond that forms between a hydrogen atom of one water molecule and the oxygen atom of another molecule, giving water many of its unique properties?

Hydrogen bonding

Select the statements below that accurately describe part of the thermohaliine conveyor.

In the Pacific, upwelling occurs off the southern coast of the Alaskan (Aleutian) islands. Surface water flows to the west from the Pacific to the Indian Ocean and on to the Atlantic Ocean. In the Atlantic, surface water in the conveyor moves to the north and deep water moves to the south.

Where are the color bands made from SST the least complicated?

In the open ocean

Which of the following changes are likely to take place in the warm phase (El Niño) of ENSO?

Increased rainfall occurs in the central Pacific. Reduced rainfall occurs in the western Pacific.

All the areas listed below are areas of either upwelling or descending water in the thermohaline conveyor. Select the area of upwelling water.

Indian Ocean

As rains falls on the surface of the ocean, the salinity of the surface water decreases. What happens to the density of the surface water? (Ignore temperature as a factor here.)

It decreases.

During an El Niño, what happens to the thermocline in the eastern Pacific?

It is pushed downward as the surface layer of warm water is expanded.

What is hydrogen bonding in water?

It is the bond that forms between the positively charged hydrogen atom of one water molecule and the negatively charged oxygen atom of another.

What is the result of having two hydrogen atoms on one side of a water molecule and an oxygen atom on the other side?

It results in water molecules having a polarity.

What role does Hadley cell circulation play in moving the effects of ENSO around the globe?

It transports the effects north and south by connecting with the east-west Walker cell circulation.

In addition to reduced levels of insolation, what processes lead to the formation of cold water at the poles?

Lack of clouds allows for more outgoing longwave radiation. Cold, dry air descends. Sea ice increases the average surface albedo, reducing the amount of energy absorbed from the Sun.

Identify the factors that contribute to the formation of abyssal water.

Low temperature High salinity

Which location tends to experience increased rainfall during the cold phase of ENSO?

Northeastern Australia

In general, the western side of an ocean will be warmer than the eastern side along the same line of latitude. Why is this?

Ocean currents move cold water toward the equator on the eastern sides of oceans. Ocean currents move away from the equator on the western sides, bringing warmer water to higher latitudes.

How do color bands made from SST data from the open ocean compare to bands made from the SST data collected near continents?

Open ocean bands mostly follow lines of latitude, but bands near continents are more complicated.

Which of the following best summarizes the temporal-dependent effects of the warm phase (El Niño) of ENSO on climatic conditions across Earth?

Overall, the effects are most strongly experienced during each hemisphere's respective winter.

Select the statements below that accurately describe global patterns of SST.

Polar regions have the coldest SST. SST are highest at low latitudes and lowest at high latitudes.

What are warm pools in the ocean?

Regions where surface water temperatures are higher than adjacent regions and that consistently form and tend to persist

Why are the warmest SST not always found along the equator?

Rising air along the equator forms clouds, and they reduce the amount of insolation received at the surface of the ocean.

Which of the following acronyms is used to indicate the temperatures of surface waters in the ocean?

SST

All the conditions below occur during either the warm phase or cool phase of the Pacific Ocean. Identify all conditions consistent with the warm phase.

SST are cooler than usual in the mid-Pacific. SST are warmer than usual in the eastern Pacific.

What is the difference between the warm phase and cool phase of the Pacific Ocean? The warm phase occurs when ___. (SST = sea surface temperatures)

SST are warmer than usual in the eastern Pacific and cooler in the mid-Pacific, and the cool phase has the opposite pattern

What is the large-scale pattern of SST in the world's oceans?

SST generally decrease from low latitudes to high latitudes.

What does the PDO index compare?

SST in the eastern and western Pacific

Why do regions with polar sea ice tend to have higher surface salinities than those of equatorial ocean regions?

Salt is excluded when ice is forming from seawater, increasing the salinity of the remaining water.

Why does the formation of sea ice increase the salinity of the surrounding water?

Salts are excluded from ice as it forms, thus increasing the salinity of the remaining water.

When referring to the ocean, what does the acronym SST stand for?

Sea-surface temperatures

What is the primary factor that causes oceanwide shifts in patterns of SST throughout the year?

Shifts in amount of insolation received during the year

Identify the ways in which ice shelves can form or grow.

Snow and other precipitation landing on the top The freezing of seawater on the bottom of the ice shelf From the outflow of glaciers from land to sea

Which of the following statements accurately describe part of the surface water circulation in the northern Pacific Ocean?

Some of the east-moving mid-latitude water heads north after approaching North America, bringing warm water to northwestern North America. The west-flowing portion of the Alaskan current mixes with the cold waters flowing out of the Arctic Ocean via the Bering current.

Sir Gilbert Walker noticed that when air pressure went up in Darwin, Australia, it went down in Tahiti (in the central Pacific) and that when it went down in Darwin, it went up in Tahiti. This linked change in air pressures is called the ___.

Southern Oscillation

How do salinity and temperature vary with depth in the ocean?

Surface waters are generally the most saline, but a complex pattern is observed within the water column. Water temperatures generally decrease with increasing depth.

What are the main factors that control the motions of water in the oceans?

Surface winds Spatial variations in the density of water The Coriolis effect

During the cold phase (La Niña) of ENSO, how does air pressure typically change in the Northern Hemisphere?

The air pressure changes are nearly the reverse of those during El Niño. The southern and East Coast of the U.S. experience higher than average atmospheric pressures.

Polar regions receive less insolation which is the major reason cold waters form there. What other factors contribute to the formation of cold waters in polar regions?

The clear skies that result from descending air allow for the escape of greater amounts of longwave radiation and more reflected light from sea ice.

How does the greater amount of cloud cover near the equator as compared to the subtropics lead to higher SST in the subtropics?

The clouds near the equator reflect more insolation before it reaches the surface waters.

Which of the following statements accurately describe part of the surface water circulation in the southern Atlantic Ocean?

The cold Benguela current flows north along the western coast of southern Africa. The Brazil current interacts and flows east with the Antarctic Subpolar (Circumpolar) current.

Which of the following statements accurately describe part of the surface water circulation in the southeastern Pacific Ocean?

The cold Humboldt current flows north along the west coast of South America. There is a west-flowing segment near the equator called the South Equatorial current.

What is the thermohaline conveyor?

The combined global-scale flow of surface and deep water

Select the statement below that best summarizes the amount of feedback between the atmosphere and the oceans.

The conditions in the oceans are closely tied to the conditions in the atmosphere, and vice versa.

Which of the following statements accurately describe part of the surface water circulation in the northern Atlantic Ocean?

The cool Canary current flows south along the northwest coast of Africa. The warm Gulf Stream flows in a northernly direction along the East Coast of the U.S.

What defines the Southern Oscillation?

The correlated reversals in air pressure in Darwin, Australia, and in Tahiti (central Pacific)

Select the factors listed below that explain the latitudinal variations in salinity, temperature, and density of seawater.

The direction air masses are moving The amount of precipitation The amount of insolation

What helps drive the east-west circuit of air in the tropics?

The formation of warm pools and the rising air found above them

What is overturning in the ocean?

The mixing of deep and surface waters that occurs when their densities are similar

Why do water molecules have a polarity?

The two hydrogen atoms with a positive charge align on one side of the molecule, leaving a negative charge on the oxygen atom on the other side.

In addition to the amount of insolation received, what other factors influence patterns of SST in the ocean?

The upwelling of cold water Adjacent landmasses Ocean currents

Which phase of ENSO is associated with colder than normal SST in the western Pacific?

The warm phase

Which region is an oceanic warm pool?

The waters between China and Australia near Southeast Asia

What is the surface water circulation pattern in the western Pacific Ocean?

There are two large subtropical gyres (one in each hemisphere), both of which flow west along the equator until one heads north and one heads south.

Why does most of the surface of the ocean have relatively sparse life and organic productivity?

There is a lack of nutrients in the water.

Select the correct description of surface water circulation patterns in the southeastern Pacific Ocean.

There is a large counterclockwise-flowing gyre.

Select the statement below that best describes the surface water circulation pattern in the Northern Pacific Ocean.

There is a large, clockwise-flowing subtropical gyre.

What is the pattern of surface water circulation in the southern Atlantic Ocean?

There is a large, counterclockwise-rotating gyre.

Select the statement below that accurately compares the doldrums and the horse latitudes.

They both are areas with weak surface winds; the doldrums are at the equator, and the horse latitudes are at 30ο.

What happens to the sodium and chlorine ions created when table salt dissolves in water?

They each are surrounded by water molecules and are kept separate.

How do abyssal ocean waters form?

They form as cold and saline water sinks near the poles.

How often do the atmosphere and oceans interact?

They interact constantly.

In what direction do currents in the ocean tend to move warm water?

Toward the poles

Select the atmospheric changes in the South American region associated with the warm phase (El Niño) of ENSO.

Trade winds weaken, reducing coastal upwelling. Descending air is pushed eastward over the equatorial parts of the Andes, reducing rainfall in Colombia and parts of the Amazon.

Identify conditions associated with the neutral phase of ENSO in the equatorial Pacific.

Warm air rises over the western equatorial Pacific warm pool, producing low pressure and abundant rain. Westward displacement of surface waters drives upwelling of cold, deep water off the coast of western South America.

What are the three surface-water temperature-determined phases of ENSO in the eastern equatorial Pacific?

Warm, neutral, and cold

What is El Niño?

Warmer surface waters from the west replacing the colder water off the west coast of South America

How does the general large-scale pattern of ocean currents affect average SST on the east and west sides of ocean basins?

Warmer waters are pushed to high latitudes on the western sides of oceans. Colder waters are pushed closer to the equator on the eastern sides of oceans.

How do winds cause motion in the waters beneath them?

Winds transfer some of their momentum onto the surface of the water.

Ocean water can be set in motion by differences in the ____, which is largely controlled by temperature and salinity. Once the water is in motion, its path is deflected by the ____ effect.

density Coriolis

Table salt ____ in water because of the polar nature of water molecules.

dissolves

The generally weak winds along the equator are the equatorial ___, whereas the weak winds found in the region of 30ο north and south are called the ____ latitudes.

doldrums horse

Ocean currents move warm water poleward. This happens because ___.

energy is moved from areas of energy excess to areas of energy deficit

The freezing of seawater, ice outflow from glaciers, and additions of snow can all contribute the growth of ___ shelves.

ice

The lack of nutrients in surface waters in most of area of the ocean causes ___.

low marine productivity

A moderately deep thermocline, an average-sized warm pool, and rising air in the equatorial western Pacific with surface winds blowing in from the east, characterizes the ___ phase of ENSO.

neutral

When the density in a column of water is similar, bottom waters can rise as surface waters sink. This mixing of waters from different depths is called ___.

overturning

Marine organisms living in the water column are referred to as ___, whereas organisms living on or in the ocean floor are referred to as ___.

pelagic; benthic

The warmer, less dense upper portion of the ocean that absorbs energy from the Sun is called the ___ zone.

photic

Within the pelagic zone, light penetrates the ___ zone but is unavailable in the aphotic zone.

photic

Coral reefs are formed by ___.

small marine animals that live in symbiosis with algae and make homes of calcium carbonate

The global equator-to-pole variations in SST are best explained by the ___.

supply of insolation

When climatic conditions in one region affect the climatic conditions in a distant region, the associations between the events are called ___.

teleconnections

The Ekman spiral defines the change in direction and velocity of ocean water with depth, and is the result of both ___ and a decrease in shearing force.

the Coriolis effect

What are teleconnections?

the links between climatic changes in one region and climatic changes in a distant region

The photic zone is the ___.

the upper layer of the ocean that is lit by the Sun and tends to be warm and less dense than deeper water

The thermal boundary in the ocean between upper warmer waters and colder deeper waters is the ___.

thermocline

The combined global scale flow of surface and deep water is called the ___.

thermohaline conveyor

Surface waters in the ocean are moved mainly by ___.

winds transferring some of their momentum onto the surface