Oceanography Introduction & Seawater Properties

Flashcards covering concepts of energy transfer, light and sound properties in seawater, and factors influencing oceanic surface salinity based on the provided lecture notes.

Radiation

The direct transfer of heat energy from the sun.

Reflection

The portion of energy, such as from the sun, that bounces off a surface and does not enter the water, influencing the global heat budget.

Conduction

A molecular process of energy transfer within the ocean, where water molecules bump into each other and share energy.

Convection

A fluid process of energy transfer in the ocean, where water masses move, conveying energy (e.g., surface currents).

Surface Currents

Walls or blobs of water that share similar temperature and salinity properties, conveying energy as they move.

Turbulent Mixing

The mixing of the upper layer of water in the ocean, influenced by wind and waves, which transfers energy.

Light in Seawater

Radiant energy from the sun that, once it enters seawater, behaves with shorter wavelengths having more energy and penetrating deeper than longer wavelengths.

Shorter Wavelengths (Light)

Light with more energy (e.g., blue and violet light), allowing it to penetrate more deeply into clear ocean water.

Longer Wavelengths (Light)

Light with less energy (e.g., red light), which remains in shallower water and does not penetrate as deeply.

Absorption (Light)

The conversion of electromagnetic energy (light) into other forms of energy within water, for instance, by photosynthetic organisms or organic/inorganic molecules.

Scattering (Light)

A change in the direction of light as it reflects off particle surfaces in water, diverting it from its original path.

Attenuation (Light)

The exponential decrease of light intensity with depth in the water column, caused by both absorption and scattering.

Coastal Ocean Water (Light Penetration)

Water on the continental shelf characterized by higher particle concentrations (sediment, plankton) which significantly increase light attenuation compared to clear ocean water.

Estuary Water (Light Penetration)

Coastal water bodies with high input from land (sediments, nutrients) and high biological productivity, leading to very high light attenuation and extremely shallow light penetration.

Axial Modulus

A variable that describes how water compresses; a high value indicates difficulty to compress, while a low value indicates easier compression.

Speed of Sound in Seawater

Approximately five times faster than in air, it increases with increasing temperature, salinity, and depth, and decreases with their reduction.

Sonar (Sound Navigation and Ranging)

A technology that uses sound waves to detect objects and determine distances underwater by emitting pulses and measuring the time for the echo to return.

Echolocation

A biological process, observed in dolphins and whales, where organisms generate sound pulses and use the returning echoes to navigate, detect prey, and communicate.

Side Scan Sonar

A type of sonar used to create detailed images of the seafloor, revealing features like shipwrecks, geological layers, and bottom types based on varying densities.

Bathymetry

The measurement of water depth and the mapping of underwater terrain, including ridges, valleys, and contours, often achieved using sonar.

Micronekton

Small fish, crustaceans, and shrimp that form layers in the water column and serve as a food source for larger marine organisms like tuna.

Dissolving (in Water)

The process where water molecules isolate and surround ions (like sodium and chloride), preventing them from recombining and dispersing them throughout the water.

Salinity

The total amount of inorganic salt dissolved in a unit of water.

Isohaline

A line connecting points of constant salinity on a map or chart.

Evaporation and Salinity

Zones of high evaporation (removal of water, not salt) result in higher surface salinity in the ocean.

Precipitation and Salinity

Zones of high precipitation (addition of freshwater) result in lower surface salinity in the ocean.

Freezing and Salinity

The process of ice formation removes freshwater from the ocean, leaving salt behind and increasing the salinity of the surrounding seawater.

River Flow and Salinity

Runoff from land, often carrying freshwater and some dissolved solids, typically decreases salinity in coastal ocean waters.

Polar Regions Salinity

Areas where ice is forming tend to have higher salinities because the freshwater is removed as ice, concentrating the salt in the remaining water.