Unit 10 Aquatic Science
Longshore Current
ocean current that moves parallel to shore
Sargasso Sea
region of the North Atlantic Ocean bounded by four currents, that together form a circulating ocean stream called a gyre
Rip current
relatively strong, narrow current flowing outward from the beach through the surf zone and presenting a hazard to swimmers
Eddys
smaller, temporary loops of swirling water that can travel long distances before dissipating.
Upwelling
*process in which deep, cold water rises toward the surface *typically colder and is rich in nutrients
Where are the trade winds located?
0-30 degrees N to S and they blow west
How long does it take water to make a complete circuit of the Global Conveyer Belt?
1000 yrs
What conditions are necessary for the formation of a hurricane?
80 degrees, warm water, heavy winds
Where does the global conveyer belt start?
At the poles
What are some climate effects of La Nina?
North America experiences colder than normal weather. There are les Typhoons in the Pacific and more Hurricanes in the Atlantic. Fish populations thrive off the coast of South America due to increased upwelling.
Which direction do hurricanes rotate in the Southern Hemisphere?
Clockwise
Downwelling
Cold water sinks to the bottom, marine life typically dies or leaves the area
Air masses circulate in the northern and Southern Hemisphere primarily through which form of heat transfer?
Convection
Which direction do hurricanes rotate in the northern hemisphere?
Counterclockwise
Convection currents move in air and water because of differences in what?
Density
What are the trade winds also called
Easterlies, the blow from the east to the west
ENSO
El Niño Southern Oscillation
Where are the strongest winds in a hurricane located?
Eyewall
What was the deadliest hurricane in American History?
Galveston 1900
What direction due surface currents tend to turn in the Northern and Southern Hemispheres?
Northern- turn right Southern- turn left
Hurricanes that strike the Texas coast may form in which three locations?
Gulf of Mexico, Caribbean Sea, off the coast of africa
Hot air rising from the equator and drifting at high altitudes toward the horse latitudes forms part of which cell?
Hadley cell
Where does the Global Conveyer Belt start?
In the North Atlantic when cold salty dense water sinks and begins to move south.
When is the Atlantic Hurricane season and when does it peak?
June 1 through Nov. 30, September
What was the costliest hurricane in American history?
Katrina
Which direction does the Ekman spiral deflect wind-driven water in the southern hemisphere?
Left
What is the primary type of garbage in the North Pacific garbage patch?
Plastic
Which direction does the Ekman spiral deflect wind-driven water in the northern hemisphere?
Right
In the northern hemisphere, storm surge is greatest on which side of the hurricane?
Right side
What causes storm surges?
Sea level rising then hitting land and still moving fast
How are surface currents steered?
Steered by Coriolis effect due to Earths rotation, because currents are moving slower than the winds they are more affected by the Coriolis effect than the winds (EKMAN SPIRAL)
What is the difference between upwelling and downwelling?
Upwelling brings cool nutrient-rich water to the surface and it occurs when surface currents flow away from land along a coastline. Downwelling brings warm nutrient-poor waters to coastal areas and occurs when winds blow towards land along a coastline.
Where is the Sargasso Sea and what currents surround it?
The Saragasso Sea is located in the middle of the North Atlantic Gyre and is surrounded by the Gulf Stream, North Atlantic, Canary, and North Equatorial Currents
How does the Global Conveyor Belt and ocean currents affect atmospheric carbon dioxide?
The oceans are a carbon sink. The Global Conveyor Belt carries dissolved carbon dioxide and carbon from plankton away from the atmosphere and sequesters it in the deep oceans for thousands of years.
Describe what happens to surface water temperatures in the equatorial Pacific during El Nino?
The warm surface waters of the western tropical Pacific move eastward towards the coast of South America because the western- blowing trade winds reverse direction.
Describe what happens to surface water temperatures in the equatorial Pacific during La Nina?
The western- blowing tradewinds intensify which brings colder surface water to the equatorial Pacific
What is the primary force that drives deep water currents?
They are driven by differences in density that are caused by differences in temperature and salinity. This is called thermalhaline circulation.
What are some climate effects of cool water currents?
They bring cool dry air to the adjacent coastlines, they result in a dry coastal climate
What are some climate effects of warm water currents?
They bring warm most air to northern latitudes, they produce a warm humid coastal climate, they transport heat from the tropics to the northern latitudes, and they have a moderating effect on the climate of adjacent land areas
What is the primary direction of current flow between 30-60 degrees latitude?
To the east
What is the predominant direction of current flow between 0-30 degrees latitude (near the equator)?
To the west near the equator
How does El Nino affect upwelling and the fisheries off the coast of South America?
Upwelling of cold deep nutrient rich waters slows or stops during an El Nino. This cuts off the nutrients necessary to maintain the food web along the coast of South America. As a result fish populations crash as do populations of other species that rely on fish such as seabirds.
What are some climate effects of El Nino?
Weather patterns reverse around the globe. The Desert Southwest gets more rain than normal. Typhoons are more common in the Pacific and Hurricanes are less common in the Atlantic. Fish and seabird populations crash off the coast of South America.
What is the primary cause of SURFACE currents around the world?
Wind
Gyre
a ringlike system of ocean currents rotating clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
Coriolis Effect
an effect whereby a mass moving in a rotating system experiences a force (the Coriolis force ) acting perpendicular to the direction of motion and to the axis of rotation. On the earth, the effect tends to deflect moving objects to the right in the northern hemisphere and to the left in the southern and is important in the formation of cyclonic weather systems.
Global conveyor belt
constantly moving system of deep-ocean circulation driven by temperature and salinity, moves water around globe
Current
continuous, directed movement of seawater generated by forces acting upon this mean flow, such as breaking waves, wind, the Coriolis effect, cabbeling, temperature and salinity differences
La Niña
cooling of the water in the equatorial Pacific that occurs at irregular intervals and is associated with widespread changes in weather patterns complementary to those of El Niño, but less extensive and damaging in their effects
Are currents stronger on the western or eastern sides of the oceans?
currents on the western side of each ocean or ocean gyre are stronger, narrower, and deeper than on the eastern side of each ocean or gyre
Equatorial upwelling
drives the surface water away from the equator and brings up the water from below
Western intensification
intensification of the western arm of an oceanic current, particularly a large gyre in an ocean basin
El Niño
irregularly occurring and complex series of climatic changes affecting the equatorial Pacific region and beyond every few years, characterized by the appearance of unusually warm, nutrient-poor water off northern Peru and Ecuador, typically in late December
Ekman spiral
structure of currents or winds near a horizontal boundary in which the flow direction rotates as one moves away from the boundary
What two factors affect thermohaline circulation?
temperature and salinity
Garbage Gyre
trash vortex, gyre.... but with trash