Properties of Seawater II

Salinity

The dissolved salt content in a body of water; contributes to buoyancy, ecosystem dynamics/life, water circulation and density

Latitude

The angular distance, N or S, away from the equator.

Due to consistent precipitation rates near the equator and glacial melting near the poles, an influx of freshwater leads to diluted salt water with a lower salinity. Mid-latitude areas of the ocean have a balanced process of the addition/removal of freshwater from the ocean which keeps the salinity of the water relatively moderate.

Why is salinity latitudinal dependent?

20-30 degrees north of the equator

What areas of the ocean have the highest salinity?

• Precipitation

• Ice Melting

• River Runoff

What are the methods of H2O addition to the ocean that affect salinity?

• Evaoporation

• Ice Formation

What are the methods of H2O removal which affect ocean water salinity?

Climate

Weather conditions prevailing in an area in general over a long period of time

Yes, but indirectly. Over time, currents will bring lower salinity waters to deeper levels, altering its salinity.

Does precipitation and evaporation affect deep level salinity?

Minimal Precipitation, Minimal Evaporation

What are the evaporation and precipitation levels of a polar climate?

Moderate evaporation, Minimal Precipitation

What are the evaporation and precipitation levels of a Temperate climate?

Maximal evaporation, minimal precipitation

What are the evaporation and precipitation levels of a sub-tropical climate?

Maximal evaporation, maximal precipitation

What are the evaporation and precipitation levels of a tropical climate ?

Temperate climate

characterized by moderate temperatures, with distinct seasons (spring, summer, autumn, and winter), and temperatures that do not experience extreme highs or lows. Mid-latitudes

Tropical Climate

consistently warm temperatures, high humidity, and abundant precipitation, with a distinct wet and dry season, typically found near the equator.

Sub-tropical climate

located between the tropics and temperate zones (roughly 20° to 40° latitude), are characterized by hot, humid summers and mild to cool winters, with rainfall patterns varying depending on the specific type

Polar Climate

extremely cold temperatures year-round, with short, cool summers and long, bitterly cold winters, often resulting in treeless tundras, glaciers, or a permanent or semi-permanent layer of ice

Vertical stratification

The vertical layering of a habitat

Halocline

A zone in the water column where vertical change in salinity is relatively sharp; occurs b/w 40 degrees N/S of the equator where more dense high salinity water sits on less dense low salinity water.

Water column

The entire vertical expanse of the ocean, from the surface to the sea floor.

2 km

Below what depth is salinity very stable?

Pycnocline

A zone in the water column where density changes rapidly with depth

Surface Layer

Layer of the ocean: (2%)

• ~100 m thick

• Diurnal, seasonal, and annual fluctuations of density/salinity/temperature

• Lighted

Pycnocline Layer

Layer of the ocean: (18%)

• Tropics (permanent pycnocline)

• Mid-latitude (coincides with halocline)

Deep Layer

Layer of the ocean: (80%)

• Originates in polar/ high latitudes

• Cold (4 degrees C)

Saturation Value

The amount of gas at equilibrium that can be dissolved in a volume of water; Increases with decreased salinity and temperature, and increased pressure.

Supersaturated

A solution with a solute that exceeds the amount dissolved at saturation

Undersaturated

A solution with less solute dissolved than at saturation

Advection

the horizontal or vertical transport of seawater, or of properties within seawater like heat, salinity, or pollutants, by the movement of ocean currents

Diffusion at sea-air interface & photosynthesis (phytoplankton)

What are the two main methods by which O2 enters seawater?

• Warm Surface layer O2 rich ( 5ml/L)

• Cold Deep Layer O2 Rich (3-5ml/L)

What ares of the Ocean are O2 rich?

• Actively involved in photosynthesis and respiration

• Necessity for plants

• Regulates pH of seawater

What is the importance of CO2 in the ocean?

CO2

What carbon ion is dominant in acidic environments?

HCO3-

What carbon ion is dominant in neutral (89%) of environments?

CO3-

What carbon atom is dominant in basic environments?

10 million

1 in how many molecules of H2O dissociate into its ions?

Light Transmission

the passage of light (or other electromagnetic radiation) through a material without being absorbed or reflected

• Height of the sun

• Smoothness of the surface (more smooth, less reflective)

What is the reflection of solar radiation dependent on ?

65%

How much visible light is absorbed within the first 1.0m of water?

<1%

What percentage of light reaches 100m in very clear water

Photic Zone

the uppermost layer of a body of water that receives sunlight, allowing phytoplankton to perform photosynthesis.

Aphotic zone

portion of a lake or ocean where there is little or no sunlight. It is formally defined as the depths beyond which less than 1 percent of sunlight penetrates

Rivers

What is the main source of dissolved ions in sea water?

Detritus

Dead and decaying organic matter