Intro to Oceanography FINAL

Typical ocean salinity is 35 ppt

• Over a long period of time does the salinity of the ocean change from ~35ppt?

– No, even though salinity can build up from erosion, animals take up ions and convert them in to shells and other things which recycle the salts back in to the sediments.

– Salt spray along coastlines also removes salt. ~3.6 billion metric tons of salt removed annually

– Oceanic retreat from land leaves salt behind as well.

• Why is ocean water salty?

– Salts eroded from the crust of millions of years.

• How much salt is in the ocean?

– If dried and spread evenly, it would cover the world at a depth of 500ft.

– 9% less dense then water.

– Due to bond angles.

• Water has a bond angle of 104.5.

• Ice has a bond angle of 109.5.

– Ice takes up 9% more space then water.

A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding.

The pH of salt water is about 7-8

building blocks of all matter.

– Precipitation

– Runoff

– Icebergs (Glacial ice)

– Sea ice melting

Abrupt change of density with depth

– 33ft

• Reflection from the sky.

• Water absorbs colors differently depending on their wavelengths.

• Colors with shorter wavelengths get filtered out first, leaving those with longer wavelengths such as blue

• Composition:

– Mostly nitrogen (N2) and Oxygen (O2).

– Other gases significant for heat trapping properties.

• Lowest portion of circulation cells generate most of the wind belts.

• Trade winds

– From subtropical highs to equator.

– Northeast trades in Northern Hemisphere.

– Southeast trades in Southern Hemisphere.

• Prevailing westerlies

– from 30

–60 degrees latitude.

– Blow southwest to northeast in N. Hemisphere.

• Polar easterlies

– 60

–90 degrees latitude.

Boundaries between wind belts.

– Doldrums or Intertropical Convergence Zone (ITCZ)

– at equator.

• Regular rain fall

– Horse latitudes

– 30 degrees

• Dry

– Polar fronts

– 60 degrees latitude.

• Regular precipitation

• Deflects path of moving object from viewer’s perspective

– To right in Northern Hemisphere

– To left in Southern Hemisphere

• Due to Earth’s rotation.

• Not a Force!

– Does not accelerate the moving body.

30 degrees latitude

Albedo, or reflection coefficient, derived from Latin albedo "whiteness" in turn from albus "white," is the diffuse reflectivity or reflecting power of a surface. It is the ratio of reflected radiation from the surface to incident radiation upon it.

30 degrees • Dry

the state of the atmosphere at a place and time as regards heat, dryness, sunshine, wind, rain, etc.

The Saffir–Simpson hurricane wind scale, or the Saffir–Simpson hurricane scale for short, classifies hurricanes

• Earth’s axis of rotation is tilted 23.5° with respect to ecliptic.

– Ecliptic

– plane traced by Earth’s solar orb

Angular distance of Sun from equatorial plane

A gyre in oceanography is any large system of rotating ocean currents, particularly those involved with large wind movements.

• Average movement of seawater under influence of wind.

• 90 degrees to right of wind in Northern hemisphere.

• 90 degrees to left of wind in Southern hemisphere.

• Upwelling

– Vertical movement of cold, nutrient

-rich water to surface.

– High biological productivity.

The Sargasso Sea is a region in the gyre in the middle of the North Atlantic Ocean

– Circulates around center of North Atlantic Gyre

– Unique biology

• Sargassum

The North Atlantic Gyre, located in the Atlantic Ocean, is one of the five major oceanic gyres. It is a circular system of ocean currents that stretches across the North Atlantic from near the equator almost to Iceland, and from the east coast of North America to the west coasts of Europe and Africa.

– Also called West Wind Drift and Penguin Gyre

– Pushed by westerly winds

• Roaring 40s

– Only current to completely encircle Earth • Due to lack of land.

– Moves more water than any other current

• Surface currents move at an angle to the wind.

• The Ekman spiral describes speed and direction of seawater flow at different depths.

• Each successive layer moves increasingly to the right in the Northern Hemisphere.

– Coriolis effect

– Vertical movement of surface water downward in water column.

– Generally low biological productivity.

– What benefit?

The North Pacific Gyre, located in the northern Pacific Ocean, is one of the five major oceanic gyres. This gyre covers most of the northern Pacific Ocean.

A crest is the point on a wave with the maximum value or upward displacement within a cycle. A trough is the opposite of a crest, so the minimum or lowest point in a cycle.

• Spilling

• Plunging

• Surging

– Water depth < 1/20 of wavelength

• Directly related to wave energy.

• Wave heights usually less than 2 meters (6.6 feet).

• Breakers called whitecaps form when wave reaches critical steepness.

• Beaufort Wind Scale describes appearance of sea surface.

• USS Ramapo (1933): 152-meters (500 feet) long ship caught in Pacific typhoon

• Waves 34 meters (112 feet) high

• Rogue waves:

– Freak waves that come out of nowhere.

– Created by constructive interference.

– Formed by the interaction of a wind wave and a swift surface current.

– Common in southeastern tip of Africa.

Average water surface elevation at any instant, excluding local variation due to waves and wave set-up, but including the effects of tides, storm surges and long period seiches

• “Great wave in harbor”

• Seismic sea waves

– Earthquakes, landslides, volcanoes

• Can travel at speeds close to 500mph.

the time it takes one full wave—one wavelength—to pass a fixed position.

• Associated with pycnocline.

• Larger than surface waves.

• Caused by tides, turbidity currents, winds, ships.

• Possible hazard for submarines.

– In-phase wave trains with about the same wavelengths.

a true tidal wave. 

• Wall of water that moves upriver.

• Caused by an incoming high tide. • Occurs in some low-lying rivers.

• Can be large enough to surf or raft.

Moon furthest from Earth

The Bay of Fundy is a bay on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine.

• Center-seeking force

• Tethers Earth and Moon to each other

– Quarter moons.

– Tidal range least.

– Quadrature.

Diurnal Tide

12 hr 25 min cycle

A whirlpool is a swirling body of water produced by the meeting of opposing currents. The vast majority of whirlpools are not very powerful.

between Moon and Earth.

a tide just after a new or full moon, when there is the greatest difference between high and low water

a narrow, variable band of very strong, predominantly westerly air currents encircling the globe several miles above the earth. There are typically two or three jet streams in each of the northern and southern hemispheres.

a seasonal prevailing wind in the region of South and Southeast Asia, blowing from the southwest between May and September and bringing rain (the wet monsoon ), or from the northeast between October and April (the dry monsoon ).the rainy season accompanying the wet monsoon.

El Niño is a band of anomalously warm ocean water temperatures that periodically develops off the Pacific coast of South America.

Arctic circumpolar current

dry with little wind

convection cell from 30 to 60 degrees

25 hrs 50 min

Ocean acidification

tsunami

faster, deeper than eastern gyres

Centripetal force and gravity

23.5

Time between 2 successive waves

internal wave

whirlpool

North Pacific gyre

Antartic Bottom water

constructive

Declination

Barycenter

88.4

Covalesent Bonds

Ice

plunging, spilling, surging.

crest

Spring Tide

Tidal Bore

35 ppt

Coriolis effect

El nino event

Rogue Waves

sodium, and chloride

Canary, Equatorial, Gulf, N. Atlantic

Quadriture

Albedo

Nitrogen

Gyre

warm and wet

Eckman transport

Jetstream

apagee

wind duration, speed, fetch

up welling

Bay of Fundy

1/7

Sargasso sea

Centripital

Hadley Cell

Grunion

Building block of all matter

Precipitation, runoff, ice melting

Water surface level