Chapter 5 Marine Science

Aerosols

Microscopic particles, into the upper atmosphere, where they increase the reflection of sunlight and slightly cool the Earth.

Convection cell

Two layers of horizontal winds moving in opposite directions.

Gyres

Under the influence of the Coriolis effect, the wind-driven surface currents combine into huge, circular systems. Span ocean basins, flowing clockwise in northern hemisphere and counterclockwise in southern hemisphere.

Ekman layer

Upper part of the water column affected by wind. Moves at 90 degrees from wind direction called Ekman transport.

Polar easterlies

Variable winds that blow at higher latitudes.

Stable

Water column where warmer, less dense surface water floats on top of denser water below. How stable the water column is depends on the density difference between the layers.

Downwelling

When the surface water gets cold enough during the winter, and it becomes denser and than deeper water and sinks.

Water mass

A body of water that can be identified by its temperature and salinity.

Great ocean conveyor

A global circulation pattern in which water cycles throughout the ocean basins. Also critical in regulating Earth's climate, and fluctuations in the conveyor have produced rapid climate changes. Also brings dissolved oxygen to the deep sea.

Permafrost

A layer of frozen polar soil.

Thermoclines

A zone in the water column that shows a sudden change in temperature with depth. The main thermocline is the zone where the temperature change marks the transition between the warm surface water and cold deep water.

Warming signal

Consistent variation in temperature over a long period of time.

Troposphere

Contains 90% of the atmosphere's gas by mass. Decreases in temperature with increase in altitude. Layer of atmosphere closest to surface of Earth ( up to 12 km high)

Stratosphere

Contains ozone, which is a form of oxygen that is more reactive thsn the oxygen found near the surface. Layer of atmosphere between 20-50 km above Earth's surface.

Oscillations

Cyclical changes in ocean circulation that affect climate.

Isotopes

Different forms of an element; number of protons the same, number of neutrons is different.

Storm surges

Form from a combination of (1) the difference in atmospheric pressure between the perimeter of a storm and the eye and (2) from spiraling winds.

Equatorial upwelling

Happens especially in Pacific. Direction changes from left to right at Equator. The North equatorial currents transport surface water to the right ( North), whereas the south equatorial currents transport water to the left ( south)

Thermosphere

Highest section of the atmosphere, and outer layer, starts above the mesosphere, and extends to 500 km above Earth's surface. As in the stratosphere, the temperature increases with altitude, but unlike the stratosphere, increase is due to small amount of regular oxygen. Absorbs energy from sun.

Westerlies

Instead of forming trade winds, some winds move from the west toward higher latitudes. Since they come from the west, they are known as westerlies. Middle latitudes.move in opposite direction of trade winds.

El Niño-Southern Oscillation

Large scale changes in atmospheric and ocean current patterns in which, among other things, warm surface water in the Pacific Ocean moves further to the east than normal. Refers to warming of surface water in Eastern Pacific.

Upwelling

Movement of large volumes of bottom water to surface, caused by Ekman tranpsort. Usually most intense. Coastal winds aren't the only source of upwelling. Coastal upwelling tends to be seasonal, occurring mainly during time of year when winds are strong and blow in the right direction along the coast.

Wind

Movement of molecules in the air. Winds are driven by by heat energy from the sun.

Thermohaline circulation

Ocean circulation driven by differences in water density, due to variations in water temperature and salinity, rather than by the wind or tides.

Equatorial currents

Produce winds that move parallel to the equator.

Cyclonic storms

Rotating storms generated over warm waters of the tropics and that occur over much shorter time spans ENSO.

Trade winds

Sinking air pushed back toward the equator. Steady winds that blow from East to West toward the Equator, replacing the hot air that rises at the Equator.

Monsoons

Strong winds that blow northward in summer and southward in winter. The Sumer monsoon causes very intense coastal upwelling.

Stratopause

Temperature levels off again, approximately 50 km up. Transition between stratosphere and the mesosphere, 50 km above Earth's surface.

Coriolis effect

The Earth is round as it rotates, anything that moves over its surface tends to turn a littlecrather than moves in a straight line. Produces equatorial upwelling, especially in the Pacific. Occurs in ring around Antartica.

Gulf stream

The current that carries water form the tropics up the east coast of the United States before turning East and bringing warm water to Europe.

Tropopause

The division between the troposphere and and the stratosphere ( 12-20 km above Earth's surface)

Albedo

The reflectivity of Earth's surface. The higher the albedo, the more solar energy is reflected back to space.

Overturn

The sinking of surface water that has become more dense than water below. Water columm is unstable.surface water sinks and mixes with deeper water.

Ekman spiral

The spiral change in the movement of water in the water column when the water is pushed by wind. Net water movement 90 degrees from wind direction. Effects of wind decreases with depth.

Thermal expansion

When a substance expands with increased temperature.