Presentation on theme: "By: Jason LaFlore Jacquelyn Matia Matt Middendorf John Onsa"— Presentation transcript:
1By: Jason LaFlore Jacquelyn Matia Matt Middendorf John Onsa Ocean Circulation PatternsBy: Jason LaFloreJacquelyn MatiaMatt MiddendorfJohn Onsa
2Ocean Circulation is the large scale movement of waters in the ocean basins. Winds drive surface circulation, and the cooling and sinking of waters in the polar regions drive deep circulationJM
3Ocean currents are constantly in motion as shown below: Ocean currents move in many different patterns affected by: wind, salinity in the water, heat, the earths rotation, etc.JM
4Ocean Circulation Patterns effect: The climateLiving conditions for plants and animals in the ocean and on landJM
5This map shows the major movements of water in oceans of the world. JM
6Two Primary Types of Ocean Circulation Wind Driven Circulation – (which involves the surface)Thermohaline Circulation- (which involves density and depth)-caused by density differences- such as temperature and salinityJM
7Ocean currents are affected by two types of forces: Primary forces- which are forces that start the motion of the waterSecondary forces- which influence the direction in which the currents flowJM
8Some of these forces include: Solar heating- causes the water to expandWinds- push the ocean waterGravity- tends to pull water (for example down a hill)Coriolis Force- which causes water to move to the right around gyresJM
9The Corolis EffectThe Corolis Effect is the deflection of objects, winds, and currents on the surface of the earth owing to the planet’s rotation.This plays a major role in the temperature and weather patterns of the earthM.M.
10The Coriolis Effect cont. As a result of the Coriolis Effect, north-flowing currents in the Northern hemisphere deflect to the east, while south-flowing currents deflect to the west. The opposite is true for the Southern Hemisphere.This plays a major role in ocean currents and circulation.M.M.
11Demonstration of the Coriolis Effect This shows how the prevailing surface winds flow.As you can see, it is rather interesting how the warmer westerly winds flow north and the trade winds from the northeast as well as the polar easterlies flow south.M.M.
13The Oceanic Circulation Cycle Near surface seawater begins its travel deep into the ocean in the North Atlantic. The downwelling of this water is caused by high levels of evaporation which cools and increases the salinity of the seawater located here.This seawater then moves south along the coast of North and South America until it reaches AntarcticaAt Antarctica, the cold and dense seawater then travels eastward. During this part of its voyage the flow splits off into two currents that move northward.In the North Pacific (off the coast of Asia) and in the Indian Ocean (off the coast of Africa), these two currents move from the ocean floor to its surface creating upwellings.The flow then becomes near surface moving back to the starting point in the North Atlantic. One complete circuit of this flow of seawater is estimated to take about 1,000 years M.M.
14ConclusionsThe Coriolis Effect stems from the fact that at different latitudes on the earth, different points experience different rates of rotation. This causes certain objects to be “deflected” from their original path.As we can see, the Coriolis Effect has a large impact on the the patterns of ocean circulationThis effects the weather and climate of the world by directing winds and warm or cold ocean currents to certain parts of the globeThis process takes a long time however, often up to 1,000 years M.M.
15Ocean Circulation Patterns The Historical Foundations:Earliest knowledge of Ocean Currents came from various ship captains and explorersMatthew Fontaine Maury- Maury was the first person to use large amounts of ocean data in a study of surface currents. He also was responsible for publishing the first pilot charts and sailing directions for all the oceans of the world.J.O.
18One of two Circulation Patterns found in all Oceans across the world. Surface CirculationOne of two Circulation Patterns found in all Oceans across the world.Surface Circulation is the Horizontal movement of water that is driven by the force of winds at the surface.J.O.
19Surface Circulation Cont Surface Circulation is driven by winds.These winds are determined by the Earth’s radiation budget which determine net heat gain at low latitudes and net heat loss at high latitudes.Sets up hemispheric and atmospheric circulation cells which breaks up into three main cells pre hemisphere: the Hadley cell, Ferrell cell, and polar Cell.J.O.
20Surface Circulation Map J.O.Taken from the Website:
21Thermohaline Circulation Pattern Thermohaline Circulation is the second of Circulation patterns that effects the earth’s oceans.The pattern is made up of the vertical movement of water which is driven by the density differences from variations in water.These Variations include temperature and SalinityThree main processes make up the Thermohalne Circulation PatternJ.O.
22Thermohaline Circulation Cont Processes that Make up the Thermohaline Pattern:Tidal Forces, Wind Stress, and Density differences.-The density of the sea water is controlled by temperature (Thermo) and salinity (Haline), and the circulation which is driven by density differencesJ.O.
23Thermohaline Circulation Pattern Map J.O.Taken form the website:
24La Nina Means the Little Girl Also known as El Viejo Refers to cooler than normal sea-surface temperatures in the central and eastern tropical Pacific Ocean that impact global weather patternsConditions recur every few years and can persist as long as 2 yearsJL
25CausesPreceded by a buildup of cooler-than-normal subsurface waters in the Tropical PacificEastward-moving atmospheric and oceanic waves help bring the cold water to the surfaceEasterly trade winds strengthen and sea-surface temperatures (SST) drop below normalJL
27Difference Between El Nino and La Nina Both refer to large-scale changes in sea-surface temperature across the eastern tropical PacificSea surface readings off South America’s west coast range from the 60s to the 70s in degrees Fahrenheit, while they exceed 80 degrees Fahrenheit in the “warm pool” located in the central and western PacificThe “warm pool” expands to cover the tropics during El Nino, but during La Nina, the easterly trade winds strengthen and cold upwelling along the equator and west coast of South America intensifiesSea-surface temperatures along equator can fall to 7 degrees below normalJL
29Global Impacts Produces opposite climate variations from El Nino Parts of Australia and Indonesia are prone to drought during El Nino, but are typically wetter than normal during La NinaJL
30U.S. ImpactsOften features drier than normal conditions in the Southwest in late summer through the subsequent winterDrier than normal conditions also typically occur in the Central Plains in the fall and in the Southeast in the winterThe Pacific Northwest is more likely to be wetter than normal in the late fall and early winter with the presence of a well-established La NinaLa Nina winters are usually warmer than normal in the Southeast and colder than normal in the NorthwestJL
31Occurrence and LengthEl Nino and La Nina occur on average every 3 to 5 yearsHowever, in the historical record, the interval between events has varied from 2 to 7 yearsLa Ninas have been half as frequent as El NinosConditions typically last approximately 9 to 12 monthsSome episodes may persist as long as 2 yearsJL