Marine Science Test #2 Review

Chapter 6-9

Covalent Bonds

A chemical bond that involves the sharing of electron pairs between atoms

Cohesion

The attachment of water molecules to each other by hydrogen bonding

Adhesion

The attachment of water molecules to other surfaces that allows for wetting

Surface Tension

The elastic tendency of a fluid surface which makes it acquire the least surface area possible

Heat Capacity

The amount of heat which is required to raise the temperature of one gram of a substance by 1 degree Celsius

Latent heat of vaporization

Heat added to or removed from a liquid during evaporation or condensation that produces a change in state but not a change in temperature

Sources

The flux into a geochemical reservoir

Sinks

The flux out of a geochemical reservoir

Steady-state

The case where a system or process does not change in time; inputs and outputs are balanced

Conservative

A constituent that occurs in high and uniform concentration in seawater and is found in constant proportion to other conservative elements

Non-conservative Elements

Elements whose proportions in seawater vary in space and time, usually because they are involved in biological or chemical processes and have short residence times

salinity

The saltiness or dissolved salt content of a body of water, usually expressed in grams per kilogram or parts per thousand by weight.

Principle of Constant Proportions

States that the proportions of major conservative elements remain nearly constant with respect to each other even though total salinity may change from place to place.

Pycnocline

A layer in the ocean in which water density increases rapidly with depth.

Deep layer

The portion of the ocean below the pycnocline where there is little additional change of density with increasing depth.

Stable

Refers here to a water column where density increases with water depth.

Primary producers

Autotrophs - Organisms capable of synthesizing their own food from inorganic substances using light or chemical energy.

Nutrients 

In the ocean, any one of a number of substances, such as nitrogen and phosphorus, that provides nourishment for growth or metabolism in primary producers.

Photosynthesis

The process by which a green plant turns water and carbon dioxide into food when the plant is exposed to light.

Respiration

A biochemical process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances.

Remineralization

The breakdown or transformation of organic matter into its simplest inorganic forms.

Redfield Ratio

The atomic ratio of carbon, nitrogen and phosphorus found in phytoplankton and throughout the deep oceans (C:N:P. = 106:16:1).

Does water have high or low heat capacity? (Why?)

High because of the hydrogen bonds that form between its molecules

What does water’s heat capacity mean for the role of the ocean in global climate?

The ocean transports huge amounts of heat around the globe, controlling global climate

What are the basic properties of water?

High surface tension, good solvent, density, high heat capacity

How do some of the basic properties of water change with changes in salinity?

If salinity increases: water becomes denser, its freezing point decreases, electrical conductivity increases, and its boiling point rises

Why are the basic properties of water important to the ocean?

they regulate its temperature, facilitate the transport of nutrients and waste, drive ocean circulation, and create a stable habitat for marine life

What is salinity?

the total amount of salts dissolved in the water

How much salt is in the ocean (g/L or average PSU)?

35

Where does the salt in the ocean come from?

the weathering of rocks on land and openings on the seafloor

What are the main few constituents of salt?

Na and Cl

What is the principle of constant proportions?

The absolute amount of salt in seawater varies, but the relative proportions of the ions are constant (ratio of salts in seawater is constant throughout the ocean)

How is the principle of constant proportions used in ocean chemistry?

It is used for testing for only one salt ion (chloride usually) to determine the total amount of salt present

What are conservative vs non-conservative constituents of seawater?

Sodium vs Oxygen and Nitrates

What does it mean to be a conservative constituent?

Not impacted by the biological or physical nature of water

What is the thermocline?

Where water temperature changes rapidly with depth

What is the halocline?

A zone of rapid change in salinity

What is the pycnocline?

A zone of rapid change in density

What is an isopycnal?

lines of constant density on T-S diagrams

What does a “water mass” look like on a T-S plot?

a point for a homogeneous water mass or a curve for a water mass that varies with depth

How deep does light penetrate (on average) in the ocean?

20 m

What is the zone called where the light penetrates the ocean (deepest)?

euphotic zone

Why does the zone called where the light penetrates the ocean (deepest) matter?

It is a part of the ocean with sufficient light for photosynthesis to occur

What are the reactants of photosynthesis?

energy, carbon dioxide, water

What are the products of photosynthesis?

sugar, oxygen

What are the reactants of respiration?

sugar, oxygen

What are the products of respiration?

carbon dioxide, water, energy

What nutrients do phytoplankton need to live?

dissolved nutrients, such as inorganic carbon

What is the Redfield ratio?

Ratio of material observed in phytoplankton (106:16:1)

What is the significance of the Redfield Ratio?

It defines how much C,N, and P phytoplankton need to grow

What are the major groups of material dissolved in seawater?

Salts, gases, nutrients, trace elements

What is the example of salts that are dissolved in seawater?

NaCl, Mg, SO²₄, Ca, K

What is the example of gases that are dissolved in seawater?

Nitrogen, Oxygen, Carbon Dioxide

What is the example of nutrients that are dissolved in seawater?

NO₃, Phosphorus

What is the example of trace elements that are dissolved in seawater?

Iron and Zinc

What impacts the distribution of salts in the water column (conservative or non-conservative)?

Conservative: Evaporation, Precipitation, Runoff, Ice Melt, Ocean Currents, Vertical Mixing

Non-Conservative: Biological uptake and decomposition, scavenging, hydrothermal vents, gas exchange

What impacts the distribution of gases in the water column (conservative or non-conservative)?

Mixing processes and biogeochemical activity

What impacts the distribution of nutrients in the water column (conservative or non-conservative)?

Conservative: Physical mixing process

Non-Conservative: Biological processes such as photosynthesis, physical like upwelling, chemical like redfield ratio

What impacts the distribution of trace elements in the water column (conservative or non-conservative)?

a complex interplay of physical, chemical, and biological processes

How do you calculate residence time?

Inventory (mass)/rate (mass/time)

What are you assuming when you calculate residence time?

The system is at steady state

What is steady state?

If the oceans are not getting saltier and their composition is not changing

Dead Zones

An area in a body of water, especially an ocean, having oxygen levels that are not adequate to support life.

Eutrophication

The process by which a body of water becomes enriched in dissolved nutrients that stimulate the growth of aquatic plant life and usually result in the depletion of dissolved oxygen.

Biological pump

The ocean’s biologically driven transfer of carbon from the atmosphere and surface ocean to the deep sea.

Ocean Acidification

The reduction in the pH of the ocean over an extended period of time, caused primarily by uptake of carbon dioxide (CO₂) from the atmosphere.

Attenuation

Refers here to the reduction in intensity of light with respect to distance travelled through a transmission medium.

Scattering

The deflection from a straight path of light or other energy waves passing through an imperfect medium (such as water filled with particles).

Absorption

The process by which a substance takes in energy when light or sound waves are encountered, as opposed to reflecting the energy.

Sound Shadow Zones

An area through which sound waves fail to propagate.

Deep sound channel

A horizontal layer of water in the ocean at which the speed of sound is at its minimum and low frequency sounds can propagate long distances; same as SOFAR channel.

Acoustic thermometry

A technique for measuring the temperature of ocean water by measuring how long it takes sound to travel through it.

When are tidal ranges the largest?

Spring tides

When are tidal ranges the smallest?

Neap tides

Thermohaline circulation

The portion of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.

Coriolis effect

The apparent deflection of a moving object from its initial course when its speed and direction are measured in reference to the surface of the rotating Earth.

Due to the Coriolis effect, where does a rocket launched from the equator get deflected when going into the Northern Hemisphere?

Right

Due to the Coriolis effect, where does a rocket launched from the equator get deflected when going into the Southern Hemisphere?

Left

Trade winds

The prevailing pattern of easterly surface winds found in the tropics

Where do trade winds blow from in the Northern Hemisphere

Northeast

Where do trade winds blow from in the Southern Hemisphere

Southeast

Westerlies

The prevailing winds from the west to east in the middle latitudes between 30 and 60 degrees latitude

Polar Easterlies

The dry, cold prevailing winds that blow from the high-pressure areas of the polar highs at the North and South Poles towards low-pressure areas between 60 and 70° N latitude

Gyres

Any large system of rotating ocean currents, particularly those driven by global wind patterns and forces created by Earth’s rotation

Monsoon

a seasonal reversing wind accompanied by corresponding changes in precipitation, seasonal changes in atmospheric circulation and precipitation associated with the asymmetric heating of land and sea

Ekman Transport

The net motion of water as the result of a balance between Coriolis and frictional drag forces.

Where is the theoretical Ekman Transport in the Northern Hemisphere

90 degrees to the right

Where is the theoretical Ekman Transport in the Southern Hemisphere

90 degrees to the left

Western intensification

The tendency of currents along the western margins of all oceans to be particularly strong, swift, and narrow

Downwelling

The downward movement of surface waters caused by the convergence of water masses or by an increase in density

Upwelling

The process of wind-driven vertical motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water.

Divergence

A location where ocean currents diverge or move apart, characteristically marked by upwelling of water from below

Mesoscale Eddies

Ubiquitous coherent rotating structures of water with radial scales on the order of 100 kilometers that play a key role in the transport and mixing of momentum and tracers across the ocean

Southern Oscillation

The natural but irregularly occurring variation of atmospheric pressure at sea level between the eastern and western regions of the southern tropical Pacific Ocean

Water-mass

A large body of seawater that is distinguishable by its characteristic temperature and salinity range.

North Atlantic Deep Water

An important deep water-mass formed in the North Atlantic that is relatively warm (> 2°C) and saline (greater than 34.9 parts per thousand)

Great Ocean Conveyor Belt

A unifying concept that connects the ocean's surface and thermohaline circulation regimes, transporting heat and salt on a planetary scale

Capillary Waves

The smallest and first formed waves which have a period of approximately 0.1 second

Gravity Waves

A wave large enough that gravity acts as the restoring force

Restoring force of capillary waves

Surface tension