8. Deep Ocean Circulation

8. Deep Ocean Circulation - Deep Ocean Circulation Surface...

Info iconThis preview shows pages 1–18. Sign up to view the full content.

View Full Document Right Arrow Icon
Deep Ocean Circulation Surface Circulation- top ~100m Wind-driven (Ekman transport + pressure gradient = Geostrophic flow) Below 100m? Deep Circulation = Thermohaline Circulation Thermo = temperature Haline = salinity Combined = density
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What controls ocean temperatures? Deep Ocean Circulation
Background image of page 2
Temperature Temperature Variations Solar input SURFACE PROCESS! Warm deep water Forms at the surface at low latitudes and sinks into deep ocean Cold deep water Forms at the surface at high latitudes and sinks into the deep ocean
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Surface Temperature
Background image of page 4
Temperature- 3000m
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Temperature in situ temperature (T) The temperature of the water at depth (under pressure) Potential temperature ( θ ) The temperature of the water if it is brought up to sea level and analyzed (atm pressure) in situ temperature- Under pressure- molecules closer together- temps tend to be higher
Background image of page 6
Salinity Salinity = amount of salt compared to pure water Units g/kg (1 in 1,000) (1 g salt in 1 kg water) ppt (part per thousand) or per mil (per thousand) psu = practical salinity units- compares conductivity of seawater to a standard ~ to ppt
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Salinity Average = 35‰ Range = 32 - 37‰ Salts Dissolved ions (Na + , Cl - , Ca 2+ …) Mostly products of chemical weathering of the continents
Background image of page 8
Salinity
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Salinity Carbonate weathering CaCO 3 + H 2 O + CO 2 Ca 2+ + 2 HCO 3 - Silicate weathering 2 KAlSi 3 O 8 + 2 H 2 O + 2 CO 2 Al 2 Si 2 O 5 (OH) 4 + 4 SiO 2 + 2 K + + 2 HCO 3 - Carbonic acid H 2 CO 3 Bicarbonate Dissolved ions clay Dissolved ions
Background image of page 10
Salinity Oceans saltier than river water Repeated evaporation and rainfall Water Weathers rock- delivers salts to ocean Evaporates – rains out on land Weathers and delivers more salt
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Salinity Is the ocean getting more salty? No Dissolved ions are also removed Biological processes Evaporite deposits Reactions (ie. Hydrothermal vents) Sea spray Steady State - salts are being removed at ~ the same rate they are being delivered
Background image of page 12
Salinity Through Time Warren, 2010
Background image of page 13

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Salinity Salts in ocean = all of the elements in the crust and the atmosphere Only 14 elements in seawater have concentrations > 1 ppm (part per million by weight) Major elements 7 elements make up 99.9% of all the salts in the ocean
Background image of page 14
Salinity
Background image of page 15

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Salinity Major Constituents of Seawater Chlorine Cl - 19.35 g/kg Sodium Na + 10.76 Sulfate SO 4 2- 2.71 Magnesium Mg 2+ 1.29 Calcium Ca 2+ 0.41 Potassium K + 0.39 Bicarbonate HCO 3 - 0.14 See KKC Table 5-1
Background image of page 16
In today’s ocean - amount of major salts always the same Amount of water varies evap vs. precip – surface processes! Law of Constant Proportions
Background image of page 17

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 18
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/08/2011 for the course GLY 3074 taught by Professor Ellenmartin during the Spring '09 term at University of Florida.

Page1 / 120

8. Deep Ocean Circulation - Deep Ocean Circulation Surface...

This preview shows document pages 1 - 18. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online