Chemical Oceanography Exam 1

Marcets Principle

Principle of constant proportions

• Water can dissolve almost every solute on earth

Reaction Probability

The probability that the reaction will take place

• Usually greater if somethings in the dissolve phase

Heat Capacity

How much energy is required for the temperature to change

Vertical distribution of elements in the water column (image)

Concentration of Chemicals in Seawater

Cl, Na, Mg, SO4, Ca, K, HCO3, Br

(Know these!!!)

Global Satellite Image of Ocean Color

• - Color of the water varies due to chlorophyll

• - New maps are created on a daily basis

Chemical Cycling (Image)

Chemical Cycling

• - Reservoirs

A place of temporary residence

Chemical Cycling

• - Nitrogen → NO3- (Nitrate)

Used to make proteins and enzymes, also important for mRNA

Chemical Cycling

• - Phosphorus - PO4^3-

Used for RNA + DNA and phospholipids

Chemical Cycling

• - Silica - SO4(OH)4 (Silicate)

Used to make tests (exoskeletons)

Global Nitrate Distribution (Image)

Ocean Circulation

Movement of water

The Oceans conveyor belt system

Movement of water around the world

Timescale of Ocean

Shows time and spacial variability

Timescale of Ocean

• - Why care about temporal variability?

To see how things change over time or with seasons

Oceanic Processes

• - This model depicts it like a factory

• - Biochemical cycling

The Rock Cycle

This is a box model

Oceanic Processes - Human Impact

• - Red = Human impact

• - Humans have changes the steady-state environment

• - 70 + 21.9 = 91.9 pg c/yr - input

• - 70.6 + 20 = 90.0 pg c/yr - output

Residence Time =

Total amount of substance / total rate of supply or removal from a reservoir

Major Constituents

• - 6 most abundant chemicals in ocean

• - Long residence time

• - Well mixed

• - Not well chemically reactive

• - Not important biologically

• - Tend to be the same in all open oceans

Turnover time

• - Similar to residence time but you look at specific processes to fill a reservoir

• - Size of reservoir / specific process

IOOS

• HOTS

Hawaii Ocean Time Series

IOOS

• BATS

Bermuda Atlantic Time Series

• - Been measuring data for centuries

• - Away from human influence

IOOS

• UNOLS

University National Oceanography Laboratory System

• - Universities that work together for oceanography work

• - Centered at the university of Washington

IOOS

• GOOS

Global Ocean Observatory System

• - Runs IOOS

IOOS

Integrated Ocean Observatory System

• - Split into ocean and coastal

Hydrological Cycle (image)

(Learn how to read this)

Water Molecules

• - Polar Covalent Bonds

• - One water molecule can have 4 others water molecules connected to it via hydrogen bonding

• - Hydrogen bonds are weak

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The phases of water

• - Solid - ice

• - Liquid - water

• - Gas - vapor

• - Density = mass/volume

• - Hydrogen bonds push crystals apart when forming ice. This makes ice lighter (less dense) than water

High boiling and freezing points

• - Amount going into liquid state = amount going into gaseous state

• - Amount going into solid state = amount going into liquid state

• - H2O had different freezing and boiling points due to the energy used to create hydrogen bonds

High latent heats of vaporization and melting

• - Latent heat of melting - amount of gram of ice turning into liquid. Energy needed/released to break hydrogen bonds (same for vaporization)

• - Very important for storms

Heat Capacity

• - How much heat can be absorbed per unit of temperature are increase

• - Takes a lot of energy to get water to change temperature

• - Heat goes into hydrogen bonds instead of warming up the water

Universal Solvent

• - Dissolves lots of materials (virtually every solute on earth)

• - NaCl (s) → Na+ (aq) + Cl- (aq)

• - The positively charged hydrogen ions are attracted to negative charges and will form around the negative molecule in a hydrogen shell which prevents the negative ion from bonding to anything else

• - Oxygen does the same to positively charged ions

Impacts of Salinity on physical properties of water

• - If salinity is increased the freezing point goes down.

• - Density increases with salinity

Residence time is defined as: The size of the _______ divided by the rate of _______ or ________

Reservoir, inflow, outflow

What has unusual properties because it forms _____ bonds with other water molecules

Hydrogen

Density is defined as the _____ per unit ______

Mass, volume

Hydrogen bonds between water molecules are due to the ______ covalent bonds with large dipole

Polar

Saltwater is _____ dense than pure water

more

What is in seawater (image)

What is in seawater

• Major Ions

Cl- (55.0%)

NA+ (30.6%)

SO4^2- (7.7%)

Mg2+ (3.7%)

Ca2+ (1.2%)

K+ (1.1%)

• - Unrestrictive

• - Conservative ions

• - Characteristics

• - - Long residence time

• - - “Constant Proportions”

What is in seawater

• Minor Ions

Sr2+, Br-, C (0.7%)

• - Reactive or used by organisms

• - Short residence time

• - Nonconservative ions

What is in seawater

• Mass Flux

The amount of particles that move through a unit area in a unit of time

• - Looks at what flows through an area

What is in seawater

• Fick’s First Law

• - The larger the concentration gradient the larger the flux

• - Important for when two bodies of water meet

What is in seawater

• Common non-major

TCO2, O2, Si, NO3-, Fe

What is in seawater

• Dissolves particles

• - 1nm or o.o1 um

• - What passes through a filter

What is in seawater

• Particulate material (suspended particle)

• - > 1 um

• - Not dissolved, solid floating particles

• - What is retained on a filter

What is in seawater

• Colloids

• - In-between

• - Can be organic or inorganic

• - Most have a negative charge (metals have a positive charge so they are often attracted)

• - Tangential Flow ultrafiltration

• - Freon is a transient tracer - used to help track the movement of water

• - Humic substances

• - High cluster-organic material

What is salinity?

• - How much (mass) of dissolved material is in the mass of seawater

• - S (%) = g of dissolved ions / g of saltwater x 1000

• - Usually no units or ppt

• - Most ocean water lies between 33-37 ppt

How is salinity measured?

• Refractometer

Index of refraction +-1% 35 ppt +- 3%

How is salinity measured?

• Inductive salinometer

Measures conductivity of ions +-0.0001% 35 ppt +-0.003%

How is salinity measured?

• Knudsen titration

Measured halides (Cl-, Br-, and I-)

How is salinity measured?

• Chlorinity

The weight in grams (in vacuo) of the chlorides in one gram of seawater (in vacuo) when all the bromides and iodides have been replaced with chloride

• - Salinity = 1.80655 x chlorinity

• - Chlorine rarely interacts with organisms

• - Not used often

Salinity sources and sinks (image)

Ratio of Constant Proportions Rule Breakers

• - Marginal seas and estuaries

• - Anoxic basins SO4^2- → S-

• - Areas of sea ice formation or melting

• - Areas of creation or dissolution of calcareous shells or coral skeletons

• - Hydrothermal vents → Sources and Sinks

• - Areas of evaporite formation/dissolution - rocks made from evaporation

• - Sea spray

• - Interstitial waters - water in sediments

Salinity is roughly defined as the mass of dissolved ______ per kilogram of _______

ions, seawater

The most accurate way to measure salinity is with a(n) _________

Inductive salinometer

The ratios of major ions in seawater are almost constant. This rule is called “The Principle of __________

Constant Proportions

What is a conservative property?

Any property that exhibits a behavior in which physical processes greatly exceed the effects of chemical or biological processes

Conservative tracers

• - To look at movement of water

• Core technique of mass water tracing

Advection

Water moves from A → B

Turbulent

A → B movement that is not linear

Diffusion vs. Turbulent Mixing

• - Molecular diffusion - slow

• - Turbulent mixing - fast

• - Molecular diffusion happens in the water column and mixes things slowly

• 
  

T-S Diagrams

Bend is a mixing point to another water body

Mixing of two water bodies

• - Starts off as very distinct as no molecular diffusion has taken place

• - Area of mixing is a thermocline - Temp

• - Thermocline gets larger with time as more mixing occurs

• - Area of mixing is a halocline - Salinity

• - Eventually forms a straight line at the same angle

Mixing of 3 water bodies

• - Small area of mixing

• - For salinity at time 3 you lose some of it

• - At time 2 you get a sharp angle, at time 3 you get a curve

• - When you get the curve, you lose your conservative mixing

Meridional

• - Along a meridian

• - From latitude to latitude

• - Transect

Latitude and Insolation

• Insolation

Looking at the function of solar radiation at the earths surface/atmosphere

Latitude and Insolation

• Insolation

• - Angle

Influences insolation

• - In the summer the _____ is more overhead

• - In the winter we are at a larger ____

Latitude and Insolation

• Insolation

• - Atmosphere

Also effects insolation

• - More gasses the sunlight has to go through

• - Higher chance of it being reflected back

Latitude and Insolation

• Insolation

• - Latitude

is important for how much sunlight you’re getting

Seasonal changes

• Soltis =

Extremes

Seasonal changes

• Summer Soltis

= June 21st - longest day

Seasonal changes

• Winter Soltis

= December 21st - longest night

Seasonal changes

• Autumnal equinox

= September 22nd - 23rd

Seasonal changes

• Vernal equinox

= March 21st

Seasonal changes

• - Temperature change

• - Cloud coverage change

• - Wind levels pick up

Variations with latitude and temperature

• High latitudes

Are cold and there’s little to no change with depth - isothermal

Variations with latitude and temperature

• Mid latitudes

Have a summer and winter line (seasonal thermocline) due to a temperature difference with seasons

Variations with latitude and temperature

• Low latitudes

Have a thermocline as it’s warm year-round

Wind patterns

• - Wind and ocean circulation are important for heat distribution

• - Wind is responsible for ½ to ¾ of heat distribution

• - Currents are responsible for ½ to ¼ of heat distribution

• - Winds drive waves

• - Longterm wind patterns create currents

• - Along the equator is a permanent low pressure zone

• - Air rises and then sinks in subtropical high

• - Poles are high pressure

Surface Currents

• - Follow wind patterns

• - Determined by long-term wind patterns

E-P

• - E = evaporation

• - P = Precipitation

E - P = -x

Precipitation > Evaporation

• - Salinity lower

• - Equator, Rivers

E - P = x

Precipitation < Evaporation

• - Salinity higher

• - Middle of gyros

Salinity Profiles

• Halocline

Rapid change in salinity

Salinity Profiles

• Isohaline

No change in salinity

Depth of mixed layer

• - More wind causes deeper mixing

• - Less wind causes shallow mixing

Density Profiles

• - Precipitation causes lower density

• - Hotter water causes lower density

• - Pycnocline = rapid change of density

• - Isopycno = no change in density

• - The book argues that temperature has more control over density, but experiments show that salinity has more of an impact on density

• - Pycnoclines act as boarders for organisms

Layer of the ocean

• - Mixed layer changes depth based on the wind

• - Polar regions have more mixing

Major water masses

Each water mass has its own distinct salinity, temperature, and density values

Thermohaline circulation

• - Density drive movement of this water throughout the ocean

• - Deep water formation

• - Deep water formation drives this circulation

• - If the formation stops then deep water will have no oxygen

Biological Pump (image)

Diffusion

• - Molecular diffusion

• - Turbulent mixing

• - Advection

• - Bursting bubbles

• - Ebullition

Mixing

• - Molecular diffusion ~ 10^-5 cm2/sec

• - Vertical turbulent mixing ~ o.1 cm2/sec

• - Horizontal turbulent mixing 100-100,000,000 cm2/sec

• - - Driven by currents

List the three properties of a water mass that are considered to be conservative

Salinity, temperature, density

Surface ocean _______ patterns are caused by variations in solar insolation

temperature

Surface ocean ______ patterns are caused by variations in the balance between evaporation and precipitation

Salinity

Mixing due to molecular diffusion is much ______ than turbulent mixing

slower