The oceans play several key roles in the climate system. They absorb and reflect solar radiation, transport heat around the globe through currents, and are the source of most atmospheric water vapor. The oceans' high heat capacity means they can store vast amounts of heat, making them the primary regulator of Earth's climate. Water has a much higher specific heat than land or air, allowing the oceans to absorb and gradually release heat. Their deep mixing and global conveyor circulation distribute heat energy worldwide. As a result, the oceans have a moderating influence on global and regional climates.

1. September 12
The role of the oceans

3. All of Earth’s water
Source: Howard Perlman, United States Geological Survey

4. WHAT ROLES DO THE OCEANS PLAY
WITHIN THE CLIMATE SYSTEM?
They absorb and reflect solar radiation.
(albedo)
They transport heat.
(climate variability)
They are source of water vapor.
(greenhouse effect, precipitation)
They store heat.
(heat capacity, latent heat)

5. “ The low-latitude oceans are Earth’s main storage tanks
of solar heat.
Bill Ruddiman
”
Earth’s Climate: Past, Present and Future

6. 3
Main reasons.

7. 1
Physical properties of water

8. The specific heat is the amount of heat per unit mass
required to raise the temperature by one degree Celsius.

9. The specific heat of water is WAY higher than any of Earth’s other surfaces.
Water
Ice
Wood, oak
Soil, wet
Tar
Earth, dry
Brick, common
Concrete, light
Clay
Lava
Glass
Granite
Steel
0 0.25 0.5 0.75 1
cal/g
Source: The Engineering Toolbox

10. Heat capacity = Density × Specific Heat
cal/cm3 g/cm 3 cal/g

11. HEAT CAPACITIES
60 : 5 : 2 : 1
water : ice : air : land

12. “ The low-latitude oceans are Earth’s main storage tanks
of solar heat.
Bill Ruddiman
”
Earth’s Climate: Past, Present and Future

13. Sun angle controls heat absorption.
Source: Ruddiman, Earth’s Climate: Past, Present and Future

14. Depth-temperature profile at 180°W
0
2000
Depth [m]
4000
90˚S 60˚S 30˚S 0˚ 30˚N 60˚N 90˚N
Latitude
179.5W
Source: Levitus and Boyer, 1994

15. Source: reefdaddy
2
Turbulent mixing

16. Source: Ruddiman, Earth’s Climate: Past, Present and Future

17. The mixed layer is uppermost layer of the ocean,
where temperature and salinity are relatively constant.

18. Boreal winter
Depth of mixed layer (meters)
Source: Giorgiogp2

19. Boreal summer
Depth of mixed layer (meters)
Source: Giorgiogp2

20. Depth-temperature profile at 180°W
0
2000
Depth [m]
4000
90˚S 60˚S 30˚S 0˚ 30˚N 60˚N 90˚N
Latitude
179.5W
Source: Levitus and Boyer, 1994

21. 3
The conveyor belt

23. The thermohaline circulation

24. Source: Jonathan Cohen

25. Average annual ocean-atmosphere CO2 flux
Source: NOAA PMEL Carbon Program

26. The residence time describes the average time a
water molecule will spend in a specific reservoir
within the hydrological cycle.

27. Age of ocean waters inferred from radiocarbon observations
Source: Gebbie and Huybers, Journal of Physical Oceanography, 2012

28. Antarctica and
Greenland
Soil Glaciers 20,000 yr
1 to 2 months 20 to 100 yr
Atmosphere Groundwater
9 days 10,000 yr
Lakes
Snow Oceans
50 to 100 yr
2 to 6 months 3,200 yr
1 week 1 year 100 years 10,000 years
1 day 1 month 10 years 1,000 years 100,000 years

29. The thermal inertia describes the resistance of a component
of the climate system to temperature change.

30. Source: Ruddiman, Earth’s Climate: Past, Present and Future

31. Sensitivity to solar heating (land vs. ocean)
Source: Ruddiman, Earth’s Climate: Past, Present and Future

32. Pacific Decadal Oscillation index
3
2
1
0
-1
-2
-3
1900 1920 1940 1960 1980 2000

33. Atlantic Multidecadal Oscillation index

35. September 20
Impacts on terrestrial climates
Source: Franklin Hunting

37. GEOG8280
XT C L AS S
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