Ch 2 - Abiotic Conditions

Key vocabulary

Abyssal zone

Deepest part of plagic zone where light can not penetrate and is permanently dark.

Albedo

Ability of a surfave to reflect solar radiation.

Anoxic zones

Locations experiencing anoxia, or without oxygen, defined as oxygen levels below 0.5 mg/L

Aphotic zone

Portion of pelagic zone with minimal light or no light available for photosynthesis, between 200m to 4000m in water depth.

Climate

Long term trends in meterological variables.

Conductions

Transfer of heat through direct contact between the surface and the atmosphere.

Coriolis effect

A result of the fact that different latitudes on Earth rotate at different speeds, causing deflection of windfs and currents.

Crest

The highest point ofg the wave.

Diurnal tide

Consistes of onlu omne high tide and one low tide per day.

Downwelling

Where surface water is forced downwards, occurs when surface currents converge.

Greenhouse Gas Effect

Gases including water vapor, carbon dioxide, methan, and nitrous oxide in atmosphere that absorb and reradiate the infrared radiation emitted by Earth.

Gyres

Large-scale circular patterns of surface circulation.

Heat budget

Balance of incoming and outgoing heat on Earth.

Hypoxic zones

Locations experiencing hypoxia, or low oxygen, defined as oxygen levels below 2 mg/l

Internal waves

Form at the boundaries of water masses of different densities and propagate at depth.

Intertidal zone

Transition zone at land and water boundary which is submerges at high tide and exposed at low tide.

Latent heat flux

Heat loss due to phase changes.

Mixed semidiurnal tides

Two high tides and two low tides per day, but the heights of each tide differs; the two high tides are different heights, as are the two low tides.

Neap tides

Period of small tidal rancge occurs when the sun, Earth and moon are at 90 degress to each other, such as when the moon is in its ¼ and ¾ phases, the solar and lunar bulges are out of phase and cancel each other out creating lower than normal high tides and higher than normal tides.

Neritic zone

Extends from the intertidal zone to depths of about 200 m at the edge of the continental shelf.

Ocean acidification

pH is decreasing, ocean water moving towards more acidic conditions.

Pelagic Zone

Open ocean area

Photic Zone

Upper level of pelagic zone with enough light for photosynthesis to occur, usually from the surface to 200 m down.

Salinity

Amount of salts and ions present in a solution.

Saturation

Refers to the amount of gas currently dissolved in the water, relative to the maximum possible content.

Semidurnal tide

Exhibits two high and two low tides each day, with both highs and both lows of roughly equal height.

Splash waves

Waves formed when something falls into the ocean.

Sping tide

Period of maximum tidal range when the sun, Earth and moon are aligned, as occurs during new and full moons, and the solar and lunar bulges are aligned and add to each other creating higher than normal high tides and lower than normal low tides.

Solubility

Refers to the amount of a dissolved gas that the water can hold under a particular set of conditions.

Still water level

Where the water surface would be if there were no waves present and the sea was completely calm.

Thermohaline Circulation

Deep water circulation cause by movement of waters of different densities (based on temperature and salinity) that stratify themselves into layers, with the densest, coldest water on the bottom and warmer, less dense water on top.

Tidal waves

Movement of the tides, tides are basically enormously long waves.

Tsunamis

Large waves created as a result of earthquakes or other seismic disturbances, are also called seismic sea waves.

Trough

the lowest point of the wave.

Upwelling

Process that brings deeper water to the surface, occurs where surface currents are diverging, or moving away from each other.

Water mass

Volume of seawater with a distinctive density as a result of its unique profile of temperature and salinity.

Wave height

The distance between the crest and the trough.

Wavelength

The distance between two identical points on successive waves, for example crest to crest, or trough to trough.

Wave steepness

The ratio of wave height to length (H/L). If this ratio exceeds 1/7 (i.e. height exceeds 1/7 of the wavelength) the wave gets too steep, and will break.