Es2003 Oceans Unit 1

Front 1

Thermohaline Circulation

Back 1

Seawater circulation in a pattern of flow dependent on variations in temperature, which affect change in salt content and therefore density

Front 2

Atlantic Meridional Ocean Circulation

Back 2

Northward flow of warm, salty water in upper layers of Atlantic. Southward flow of colder water in the deep Atlantic.

Ventilates the deep ocean

redistributes nutrients, oxygen, carbon and pH

Front 3

Potential Temperature (In oceans)

Back 3

The in situ temperature corrected for the effects of compression (pressure)

Front 4

Salinity

Back 4

Dissolved content of salt in a body of water

Front 5

Antarctic Bottom Water Formation

Back 5

a type of water mass surrounding Antarctic which sinks to depth as it mixes with less dense water above

Front 6

Polynynas

Back 6

Ice free areas of sea in the ice cover which forms at many locations around Antarctic due to cooling and ice formation. The continual freezing cools the surrounding water and increases its salinity, thus making the water more dense and sink to form deep water

Front 7

North Atlantic Deep Water formation

Back 7

Warm salty gulf stream water south of Iceland carried into Nordic Sea and further north to the Arctic. In the Nordic seas the cold, fresh polar water, and the warm, salty Atlantic water mix. Heat from the Atlantic water is released to the air above. This mixing and cooling increases the density of the surface water, becoming dense enough to sink.

Front 8

Vertical ocean circulation drivers

Back 8

Seawater density ( temp and salinity) and wind

Front 9

The Coriolis Effect

Back 9

The force a water/air mass experiences when moving in a rotating system which acts perpendicular to the direction of motion. Deflects to the right in Northern Hemisphere and to the Left in Southern hemisphere

Front 10

Ekman Transport

Back 10

the net motion of fluid as the result of a balance between Coriolis and turbulent drag forces.

Front 11

Geostrophic Current

Back 11

Oceanic flow when Coriolis effect and pressure gradient force are equal and balance each other. Geostrophic flow parallel to isobars.

Front 12

Westward intensification

Back 12

Due to Coriolis effect being largest at the poles and decreasing towards equator. Coriolis effect stronger in the latitudes of the westerlies than in the latitudes of the trade winds causing apex of gyres to be in the Western section of gyre.

Front 13

Oceanic Convergence

Back 13

Converging water causing a sea surface hill ( rotating circle with arrows pointing inward)

Front 14

Oceanic Divergence

Back 14

Diverging water causing a sea surface valley ( rotating circle with arrows pointing outward)

Front 15

Molecular Diffusion

Back 15

a cm scale process of ocean mixing

Front 16

Turbulence diffusion

Back 16

chaotic flow with irregular fluctuations in speed and direction. A mm to 100s km process

Front 17

Why is Horizontal turbulent diffusion faster than Vertical?

Back 17

Density inhibits vertical ocean mixing. Stratified waters (with less dense layer of water floating on a dense water layer) vertically mix much more slowly compared to non-stratified water. Vertical diffusion has to deal with stratified waters.

Front 18

Thermocline, Halocline, Pynocline

Back 18

Section of water profile where temperature (thermo), salinity (Halo), depth (pyno) changes very rapidly.

Front 19

What is the impact of climate change on ocean stratification and primary production?

Back 19

Surface warming = increased water stratification (warm less dense layer over cold more dense layer) = decreased vertical mixing/ decreased overturning of sea waters = decreased nutrient flow = decreased primary production

Front 20

If warm, salty water overlies cool, fresh water then T is stabalising but S is destabalising. What will happen?

Back 20

T will diffuse faster and temp will become constant throughout the water column faster than salinity. At some point T will be constant but S will not be. Salinity will be higher at the water top of the column so the water column will become unstable and will overturn and mix.

Front 21

Salt fingering

Back 21

a mixing process that occurs when relatively warm salty water overlies relatively colder, fresher water. It is driven by the fact that heated water diffuses more readily than salty water. The sinking salty cells have lost their heat and now sink whilst the rising fresh cells have gained heat and rise. This is oceanic overturning. SF leads to thermohaline staircases on water profiles.

Front 22

Conservative elements/ions

Back 22

concentration of these elements/ions normalized to salinity is constant with depth. eg Na, Cl. Non major elements which usually have only weak biological reactions, are not particle reative and are relatively soluble.

Front 23

Minor non conservative

Back 23

Ca and C are defined as part conservative. High concentrations and part nutrient type (because of their profiles)

Front 24

Nutrient (recycled) behaviour

Back 24

Concentration of these elements controlled by biological cycling. Profiles are depleted in surface waters and concentrations increase at depth. Concentrations maybe low or zero (biolimiting) at surface

Front 25

Nutricline

Back 25

slope on profile where nutrient concentrations increase rapidly

Front 26

Scavenged elements

Back 26

elements show some concentration decrease with depth. Scavenging due to adsorption of ions or ion complexes onto particles e.g bacteria are captured by large particles (feaccal pellets) and drop through the water column. Are very particle reactive, have short ocean residence times. Tend to have higher concentrations in Atlantic deepwaters compared to pacific as pacific waters are very old so there has been plenty time for these particle reactive elements to be scavenged.

Front 27

Compensation Point

Back 27

Point at depth where Photosynthesis = Respiration

Front 28

How does climate change impact ocean dissolved oxygen?

Back 28

Warmer climate= warmer surface water= increased stratification= decreased CO2= less photosynthesis

warmer climate= glacial melt=less dense water at poles= less deep water formation bringing oxygen through at depth

Front 29

Hypoxic, Suboxic, Anoxic

Back 29

Hypoxic- a lot of oxygen, Suboxic- not so much oxygen, Anoxic- no oxygen

Front 30

what is causing oceanic OMZs expansion?

Back 30

Reduction in convective mixing from surface due to increased stratification. Reduction in deepwater subduction due to decreased seawater density at deep water formation sites.

Reduction in O2 solubility in warmer surface waters. Increased O2 consumption from organic decay at depth

Front 31

Residence Time

Back 31

Total mass dissolved in ocean/ rate of supply (or removal)

Front 32

Bicarbonate

Back 32

HCO3 -

Front 33

Carbonate

Back 33

CO3 2-

Front 34

Bjerrum Plot

Back 34

concentrations of different carbon species as a function of the solution pH

Front 35

Solubility of CO2 and O2 increases when:

Back 35

low temperature, low salinity, high pressure.

Front 36

Is carbonate preserved best on the surface or at depth? In the Pacific or Atlantic?

Back 36

On the surface, in the Atlantic.

Front 37

Lysocline

Back 37

the depth at which CaCO3 dissolution begins

Front 38

Carbonate Compensation Depth (CCD)

Back 38

No CaCO3 preservation

Front 39

is calcite or aragonite more susceptible to ocean acidification?

Back 39

Aragonite

Front 40

effects of ocean acidification on CaCO3

Back 40

decreases CO3 2- which hampers CaCO3 precipitation. Also facilitates CaCO3 dissolution.