Physical Oceanography (Currents, Waves, & Tides)

77 terms by mlister

Create a new folder

Advertisement Upgrade to remove ads

Use this to help you review some of the terms and defitions associated with physical oceanography.

Surface Currents

These transfer heat from tropical to polar regions, distribute nutrients, scatter organisms and influence weather and climate.

Wind

Surface currents are powered by the sun and ______________

Gyre

Circular flow pattern of water caused by deflection of water by continents and the ocean basin.

Equator

Due to the warmth of the water, the molecules are slightly expanded in this region.

Poles

Due to the cold temperature of the water, the water molecules are slightly closer together in this region.

Countercurrents

Currents flowing on surface in opposite direction to main currents.

Undercurrents

Countercurrents beneath surface currents. Can influence conditions at the ocean surface.

Eastern

There are five of these boundary currents. They carry cold water towards the equator.

Eastern

These boundary currents are shallow and broad with boundaries that are not well defined.

Eastern

Eddies do not tend to form in these boundary currents.

Transverse

In these boundary currents, the flow is from East to West or West to East. They link eastern and western boundary currents.

Transverse

The West Wind Drift is an example of this type of boundary current.

Western

These are the fastest flowing boundary currents.

Western

These boundary currents move warm water from the equator towards the poles.

Western

The Gulf Stream is an example of this type of boundary current.

Sverdrop

This measurement of volume of water flow is equal to 1 million metres cubed per second.

Western

These boundary currents are narrow and deep and have sharp boundaries. Eddies can form.

Ekman Spiral

surface winds drive surface currents, and each layer of water drags the layer below, but the Coriolis Force changes each layer's direction slightly to make a spiral effect

Geostrophic Gyres

Gyres in balance between gravity and the Coriolis Effect.

Clockwise

Which direction do gyres flow in the Northern hemisphere?

Counterclockwise

Which direction do gyres flow in the Southern hemisphere?

Energy

Waves transmit _______________.

Long

Waves with ___________ wavelengths move the fastest.

Capillary waves

The slowest moving waves.

Tides

The fastest moving waves

Tsunami

Wave generated as a result of a seismic event.

Wave Frequency

Number of waves passing a fixed point per second.

Orbit

Nearly friction free transfer of energy from molecule to molecule in a circular path.

Progressive Wave

A wave of moving energy in which the wave form moves in one direction along the surface of the transmission medium.

Wave crest

highest part of a progresive wave

Wave trough

lowest part of a progressive trough

Wavelength

Horizontal distance between two consecutive wave crests or wave troughs

Wave Height

Vertical distance between a wave crest and an adjacent wave trough

Deep

These waves move through water greater than 1/2 their wavelength.

Shallow

These waves move through water shallower than 1/20 their wavelength

Transitional

These waves travel though water deeper than 1/20 but shallower than 1/2 their wavelength

Capillary

These waves are the first to form when the wind blows.

Capillary

Waves with a tiny wavelength less than 1.73cm. The restoring force is surface tension.

Gravity

These waves have a wavelength greater than 1.73cm. The restoring force is gravity and momentum. Wind waves are one example of these waves.

Wind

These waves tend to be less than 3m high, and have wavelengths between 60 - 150m in the ocean.

Swell

mature wind waves of one wavelength that form orderly undulations of the ocean surface

Wave Trains

Progessing groups of swell with the same origin and wave length are known as this.

Fetch

Uninterupted distance over which the wind blows without significant change in direction.

Wind Strength

The length of time the wind blows, the fetch and this are three factors that affect wind wave development.

1:7

Maximum ratio of wave height to wavelength seen in the open ocean. Also known as wave steepness.

Break

Waves with a ratio greater than 1:7 will do this.

Destructive interference

The subtraction of wave energy as waves meet producing smaller waves.

Constructive interference

The addition of wave energy as waves meet producing larger waves.

Surf beat

A result of constructive and destructive interference that is seen on shore when waves do not all appear with a uniform size. Some are larger, some are smaller.

Rogue Wave

A single wave crest much higher than usual caused by constructive interference.

Semidiurnal

This type of tidal cycle is found commonly in the Atlantic and Pacific Oceans.

Diuranal

This type of tidal cycle is found commonly in the Gulf of Mexico.

Plunging Wave

A breaking wave in which the upper section topples forward and away from the bottom, forming an air-filled tube.

Spilling Wave

A breaking wave whose crest slides down the face of the wave.

Surging Wave

A wave that surges ashore without breaking.

Wave refraction

Slowing and bending of progressive waves in shallow water.

Wave diffraction

Bending of waves around obstacles.

Wave reflection

The reflection of progressive waves by a vertical barrier. Reflection occurs with little loss of energy.

Standing Wave

a wave in which water oscillates without causing progressive wave forward movement. there is no net transmission of energy in a standing wave

Tides

the regular rise and fall of the ocean's surface influenced by the moon's gravity pulling on earth

Lunar Tide

Tide caused by gravitational and inertial interaction of the moon and Earth.

Lunar Day

24 hours 50 mins

Pytheas

Greek astronomer and navigator who first wrote about the connection between moon and the height of the tide.

High Tides

High water position corresponding to a tidal crest

Low Tides

Low water position corresponding to a tidal trough

Spring

These tides occur when the earth, moon and sun are in a straight line.

Neap

These tides occur when the earth, moon and sun are at right angles.

Solar Tides

caused by the gravitational and inertial interaction of the sun and earth

Neap

These tides result in little variation in the height of tides.

Spring

These tides are a time of greatest variation between high and low tides.

Amphidromic Point

A "no-tide" point in an ocean caused by basin resonances, friction, and other factors around which tide crests rotate. About a dozen amphidromic points exist in the world ocean. Sometimes called a node.

Tidal Bore

A high, often breaking wave generated by a tide crest that advances rapidly up an estuary or river.

Tidal Range

is the difference in height between successive high and low tides

Tidal Datum

The reference level (0.0) from which tidal height is measured.

Slack Water

a time of no current, occurs at high and low tides when current change direction

Flood Current

water rushing into an enclosed area because of the rise in sea level as a tide crest approaches

Ebb Current

Water rushing out of an enclosed harbor or bay because of the fall in sea level as a tide trough approaches.

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set