1. Phase Diagram for Water

2. Hydrogen Bonding in Water

4. Transfer Processes and Storage (Reservoirs)

6. Rate of Addition or Removal
Residence Time
Time to replace a substance in a reservoir, or average length of time a substance exists in a reservoir
Total Amount
Rate of Addition or Removal
Water in atm. = 11 days
Water on land = 1 year
Water in oceans = 3500 years

7. Importance of Water Cycle to the Earth System
Transfers heat
Sea level change
Greenhouse gas
Global warming will affect it
Renewable resource; energy source
Weathering and erosion agent
Interacts with the Carbon Cycle

8. Energy Absorbed and Released During Phase Changes of Water

9. Difference in Heating of Land and Ocean

10. Summer
Winter

13. A True Color Picture of Earth

14. amount
size

15. Sea level also changes due to temperature.

18. Top Climate-Water Issues
Sea-level rise
Snow-pack loss
Redistribution of water resources
Water vapor feedback

19. Ice Sheet Melting & Sea Level Rise

20. Rate of Sea Level Rise
(Data from IPCC WGI Summary for Policymakers)

21. Sea-Level Rise and Water Supplies
Saltwater contamination of coastal ground-water wells
Salinity encroachment on municipal water intakes from rivers
Loss of glacial meltwater
Coastal States

22. Composition of Natural Waters

23. Carbonate Equilibria: CO2 + H2O
CH3COOH  H+ + CH3COO-
CH2O + O2 => CO2 + H2O
CO2 + H2O  H2CO3
H2CO3  H+ + HCO3-

24. Chemical Weathering Limestones H2CO3 + CaCO3 <==> Ca+2 + 2HCO3-
Silicates
2H2CO3 + NaAlSi3O8 ==> Na+ + 2HCO3-
+ clay minerals
2H2CO3 + CaAl2Si2O8 ==> Ca+2 + 2HCO3-
What happens to CO2 during chemical weathering?
Role of water? pH of river water? Seawater?

25. Chemical Weathering

26. Chemical Composition of Seawater
Six major constituents
Two anions - Cl-, SO4=
Four cations - Na+, Mg+, Ca+2, K+
pH is buffered by CO2 - CaCO3 system

27. Rate of Addition or Removal
Residence Time
Time to replace a substance in a reservoir, or average length of time a substance exists in a reservoir
Total Amount
Rate of Addition or Removal

29. Sources of Sea Salt Weathering of continents Volcanic eruptions
Hydrothermal vents

32. Oxygen Concentration Solubility depends on T and Salinity
Warm, saline water holds less O2
Oxygen consumption in water column
Respiration by animals
Mixing rate of oceans
Sluggish mixing - low rate of O2 replenishment

33. Carbon Dioxide Concentration
Solubility depends on T and S
CO2 is released by animals
Mixing rate of oceans
Affects pH of seawater (What is its pH?)
Similar to concentration profiles of nutrients (PO4-3, NO3-)

34. X

37. CO2 in Seawater pH - function of dissolved CO2
Reacts with water to produce carbonic acid, which releases H+ ions
CO2 + H2O  H2CO3  H+ + HCO3- H+ + CO3-2
H2CO3 is carbonic acid, HCO3- is the bicarbonate ion and CO3-2 is the carbonate ion

38. CO2 in Seawater Carbonate system - buffers against large shifts in pH
Carbonates dissolve in deep water
Higher CO2 makes the water less alkaline (pH ≈ 7.8)
Warm, shallow water has less dissolved CO2
More alkaline than deep water (pH ≈ 8.2)
Carbonate sediments are abundant

39. Carbonate System

40. Precipitation of CaCO3
----
HCO3- + OH- => CO3= + H2O

41. Calcite (or Calcium Carbonate) Compensation Depth (CCD)
CaCO3 dissolves in deeper water due to higher CO2 content in deep water
Deepest sediments have little or no CaCO3
CCD is deeper (less dissolution) in the Atlantic Ocean than in the Pacific
Why?

43. The Carbonate System

44. Changes in the CCD for the
Past 100 m.y.