oceanography test Flashcards
What is the euphotic zone?
The top zone of water, has enough light penetrating to permit photosynthesis.
What is the photic zone?
A zone that has light but usually not enough for photosynthesis.
What is the aphotic zone?
A zone where no light penetrates.
What is the benthic zone?
The zone on the bottom of the water level; it doesn’t have to be the bottom, can be on the continental slope.
What is the abyssal zone?
The deep-sea bottom, which is dark and cold.
What are nekton?
Organisms that swim freely in ocean currents, such as fish and dolphins.
What are plankton?
Microscopic plants and animals that float around in ocean currents, including zooplankton and phytoplankton.
How does water temperature change with depth?
Water temperature should decrease with depth; the bottom layer should be slightly colder.
What is the thermocline?
A layer where temperature drops.
What is the halocline?
A layer where salinity drops.
What is the pycnocline?
A layer where density drops.
Where is temperature highest in the ocean?
Temperature is highest at low latitudes.
How does salinity vary in the ocean?
Salinity varies and is not highest at the equator due to higher precipitation.
Where is high salinity found?
High salinity is around 30 degrees latitude, where there is high evaporation and low precipitation.
What drives thermohaline circulation?
Thermohaline circulation is driven by density differences.
What drives the Equatorial counter currents?
Trade winds by Coriolis drive the Equatorial counter currents.
How do prevailing winds affect ocean currents?
They create surface currents in the water
What is the Coriolis effect?
The Coriolis effect causes water to move right in the Northern Hemisphere and left in the Southern Hemisphere.
What are eddies?
Eddies are circular currents of water
What is the difference between warm core and cold core eddies?
Warm core eddies are clockwise, while cold core eddies are counterclockwise.(flipped in southern hemisphere)
What is Ekman transport?
Water goes at an average of 90 degrees from the wind direction due to Ekman transport.
What is geostrophic flow?
Ekman transport creates a moun of water, and water travels around the mound in loop balancing the forces of gravity and the Coriolis effect.
How does the Coriolis effect influence gyres?
Gyres in the North are clockwise, and gyres in the South are counterclockwise due to geostrophic flow.
What is the relationship between air circulation and pressure?
(Trade) winds move from high pressure to low pressure, driven by pressure belts.
What is the effect of the Coriolis effect on wind?
The Coriolis effect deflects air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.(which in turn deflects water)
What is air pressure?
Air pressure is the weight caused by gravity of a column of air, varying by elevation.
What causes wind?
Wind is the result of horizontal differences in air pressure.
How many gyres are there around the globe?
There are 5 gyres around the globe: N and S Atlantic, N and S Pacific, and Indian Ocean gyre. (4 currents in each gyre)
What is the difference between western and eastern currents in gyres?
Western currents are narrow, fast, warm, and deeper; eastern currents are wide, slower, cold, and more towards the surface.
What happens when wind blows on the ocean surface?
Wind pushes water away into a coast where it has nowhere to go but down (Ekman transport), leading to upwelling that brings water from below to replace it.
Where is the Coriolis effect stronger?
Coriolis effect is stronger at higher latitudes (poles) due to the Earth’s higher rotational velocity.
How do winds affect ocean water?
Winds move ocean water through friction.
Where is high pressure located in a 3 celled model?
High pressure is at 30N/S and the poles.
Where is low pressure located in a 3 celled model?
Low pressure is at 50-60N/S and the equator.
What drives trade winds?
Trade winds go from high pressure to low pressure, driven by pressure belts.
What are the three main cells in the three-celled model of atmospheric circulation?
The three main cells are the Hadley cell, the Ferrel cell, and the Polar cell.
True or False: The Hadley cell is responsible for the trade winds.
True
Fill in the blank: The trade winds blow from the ____ to the ____ in the tropics.
east; west
What direction do the easterlies blow in the Northern Hemisphere?
From the northeast to the southwest.
Multiple Choice: Which cell is located between the Hadley cell and the Polar cell?
Ferrel cell
What is the primary driving force behind the trade winds?
The Coriolis effect and the pressure gradient force.
True or False: The Polar cell is characterized by rising air at the poles.
False
Short Answer: Describe the general movement of air in the Ferrel cell.
Air moves poleward and eastward at higher altitudes and returns equatorward and westward at lower altitudes.
What is the significance of the Intertropical Convergence Zone (ITCZ) in the three-celled model?
The ITCZ is where the trade winds from both hemispheres converge, leading to rising air and precipitation.
Fill in the blank: The easterlies are also known as the ____ winds.
trade
What is a trophic level?
The position an organism occupies in a food chain (higher is higher in the food chain/web)
What is an autotroph?
An organism that makes its own food/energy.
Photoautotroph uses sunlight (photosynthesis), Chemoautotroph uses chemicals like bacteria.
What is a heterotroph?
Consumers in food chains that eat other organisms.
What are primary consumers?
Herbivores that consume primary producers (e.g., snails, grazing animals).
What are secondary consumers?
Carnivores that eat the primary consumers.
What are tertiary consumers?
Carnivores that eat secondary consumers.
What is a detritivore?
An organism that feeds on dead/decomposing organisms.
What is a decomposer?
A detritivore that breaks down organic matter and recycles nutrients back into the environment.
What is the 10% rule?
The amount of energy in the ecosystem is decreased by 90% with increasing trophic levels because the organism only consumes about 10% of the energy.
What are abiotic factors?
Factors that affect an ecosystem that are nonliving (e.g., climate, humidity).
What are biotic factors?
Factors that affect an ecosystem that are living (e.g., bacteria, fungi).
What is the global conveyor belt?
The constant moving water due to varying temperature and salinity in the ocean (transporting warm to cold and cold to warm) as a result of thermohaline circulation.
What does ppts stand for?
Parts per thousand, a ratio used to refer to concentrations of salinity in water.
What is western boundary intensification?
Western boundary intensification is the phenomenon where ocean currents, particularly warm currents, are intensified along the western boundaries of ocean basins.
True or False: Western boundary intensification is primarily observed in the eastern boundaries of ocean currents.
False
Fill in the blank: The Gulf Stream is an example of a __________ current that exhibits western boundary intensification.
warm
Which factors contribute to western boundary intensification?
Factors include the Earth’s rotation (Coriolis effect), wind patterns, and the geometry of ocean basins.
What is the primary effect of western boundary intensification on climate?
It affects regional climates by transporting warm water poleward, influencing weather patterns and temperatures.
