Oceanography Chapter 7
Southern Boundary Currents
Southern part of subtropical gyres
Eastern Boundary Currents
Cold current that is slow, wide and shallow
Younger Dryas Event
A cold episode that took place about 11,000 years ago, when average temperatures dropped suddenly and portions of the Northern Hemisphere reverted back to glacial conditions.
La Nina
A coupled ocean-atmosphere phenomenon that is the counterpart of El Niño as part of the broader El Niño-Southern Oscillation climate pattern
Geostrophic Current
A current that forms as a result of gravity and the coriolis effect as water flows down a geostrophic hill.
North Atlantic Drift
A warm ocean current that brings warm, moist air across the Atlantic Ocean to Northern Europe
Dryas octopetala
Alpine plant with white flowers typically found in arctic regions. Evidence of its presence in current day Scandinavian forests is evidence of recent major changes in Earth's climate
Productivity
An abundance of microscopic algae, aided by upwelling of nutrient-rich water
AMOC
Atlantic Meridional Overturning Circulation. The driver of the conveyor belt circulation in the Northern Atlantic
ENSO index
Calculates El Nino/ La Nina patterns
Surface Currents
Currents that affect water to a depth of several hundred meters. They are driven mainly by wind.
North Atlantic Deep Water
Deep water mass formed in the North Atlantic Ocean. Thermohaline circulation of the world's oceans involves the flow of warm surface waters from the southern hemisphere into the North Atlantic
Antarctic Bottom Water
Densest water in the open ocean
Ekman Spiral
Describes the speed and direction of flow of surface waters at various depths
Downwelling
Downward movement of surface water to deeper parts of the ocean
Antarctic Divergence
East wind drift is deflected towards the continent, and antarctic circumpolar current is deflected away from it
Warm-core rings
Eddies that rotate clockwise
Cold-core rings
Eddies that rotate counter clockwise
Benguela Current
South Atlantic gyre, Eastern boundary. Slow moving and cold current that flows south to North along the western coast of Africa
Ocean Currents
Global patterns created from the movement of the oceans; such as the Gulf Stream
Gyres
Huge circular moving current systems dominate the surfaces of the oceans.
Atlantic meridional overturning circulation
Important component of the Earth's climate system, characterized by a northward flow of warm, salty water in the upper layers of the Atlantic, and a southward flow of colder water in the deep Atlantic
South Pacific Subtropical Gyre
Includes Southern Equatorial, Peru, Southern Pacific and East Australian currents.
North Pacific Subtropical Gyre
Includes northern equatorial, Kuroshiro, Northern Pacific and California currents
Indian Ocean subtropical Gyre
Includes, Southern Indian, Western Australian, Southern Equatorial and Algulhas currents. There is only 1 gyre in the Indian ocean.
West Australian Current
Indian Ocean Gyre, Eastern boundary current. Merges with South Equatorial Current
Algulhas Current
Indian Ocean Gyre, Western boundary current. Flows southward along Africa's east coast
Lake Agassiz
Largest glacial lake in North America that covered much of Manitoba, northwestern Ontario, and eastern Saskatchewan
Antarctic Circumpolar Current/ West Wind Drift
Main current in Antarctica, circles around the continent and flows west to east
Equatorial Currents
Major ocean currents that move parallel to the Equator
Western Intensification
Makes western boundary currents faster, narrower, and deeper than the eastern boundary counterparts. A result of the Earth's rotation.
Ekman Transport
Net water movement that is 90 degrees from the direction of the wind. To the right in Northern hemisphere, to the left in Southern hemisphere
Canary Current
North Atlantic gyre, Eastern boundary current. Broad, cold, southward flow that eventually joins the North Equatorial Current
Gulf Stream
North Atlantic gyre, Western boundary current. World's most studied current
California Current
North Pacific Gyre, Eastern boundary current. Flows southward along the coast of California
Kuroshiro Current
North Pacific Gyre, Western boundary current. Makes Japan's climate warmer
Northern Boundary Currents
Northern part of subtropical gyres
Thermohaline Circulation
Part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.
East Australian Current
South Pacific Gyre, Western boundary, flows past Wallaby Way in Sydney.
Peru Current
South Pacific Gyre. Eastern boundary, Also known as: Humboldt current
Pacific Decadal Oscillation
Pattern of Pacific climate variability similar to ENSO in character, but which varies over a much longer time scale
Walker Circulation Cell
Pressure difference causes strong southeast trade winds to blow across the equatorial South Pacific Ocean
Labrador Current
Produces abundant fog in the North Atlantic. Flows to the South
North Atlantic Subtropical Gyre
Rotates clockwise. Gulf Stream, North Atlantic, Canary, Northern Equatorial currents
South Atlantic Subtropical Gyre
Rotates counterclockwise. Brazil, Antarctic Circumpolar, Benguela, Southern Equatorial currents
Monsoon
Seasonal reversing wind accompanied by corresponding changes in precipitation and currents in the Indian Ocean
Deep Currents
Slow, cold currents at the bottom of the ocean; caused by differences in density
Meanders
Snakelike bands in the current that often disconnect from the Gulf Stream and form large rotating masses of water called vortexes
East Wind Drift
Surface current propelled by the polar easterlies
V. Walfried Ekman
Swedish physicist who developed the Ekman spiral
Conveyer-Belt Circulation
The global ocean conveyor belt is a constantly moving system of deep-ocean circulation driven by temperature and salinity
Southern Oscillation
The seesaw pattern of atmospheric pressure between the eastern and western Pacific.
Subtropical Convergence
The zone of convergence that occurs within all subtropical gyres as a result of Ekman transport driving water toward the interior of the gyres.
Upwelling
Upward movement of cold, deep, nutrient rich water to the surface
Temperature-Salinity Diagram
Used to identify deep water masses based on their characteristic temperature, salinity, and density
Western Boundary Currents
Warm current that is fast, narrow and deep
El Nino
Warm phase of the El Niño Southern Oscillation and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific, including off the Pacific coast of South America
Coastal Upwelling
Water rises from below to replace the water moving away from shore. Typically caused by offshore or side shore winds.
Eqatorial Upwelling
Water rises from below to replace water moving away from the equator to both the north and south due to Ekman transport. Water is colder and more productive than in most areas of the tropics.
Coastal Downwelling
Water stacks up along the shoreline and has nowhere to go but down. typically caused by onshore winds.
Pacific Warm Pool
Wedge of warm water on the western side of the Pacific Ocean caused by trade winds
Antarctic Convergence
Where colder, denser Antarctic waters converge with warmer, less dense sub Antarctic waters