Ocean and climate Flashcards
What is the temperature of the ocean a function of?
Incoming solar radiation, Albedo, and concentration of Greenhouse gases in the atmosphere.
What are the main four GHGs and their % volume?
Water vapour - 50%
Carbon Dioxide - 20%
Methane - 5%
Ozone - 5%
Why does warming show a greater variability in its upward trend over the last 200years, than CO2?
CO2 and warming have a multitude of effects on climate.
Identify and describe the three ways oceans regulate climate.
Atmospheric CO2 regulation - CO2 is dissolved in the ocean on a short time scale, and organic carbon is buried in marine sediments on a geological time scale.
Heat transport - oceans carry warm equatorial waters to the poles.
Reflection by sea ice - Sea ice has a higher albedo than water or land.
How much more carbon can the ocean hold relative to the atmosphere.
About 50 times as much.
How does mean sea surface temperature correlate to CO2 influx?
Lower the temperature, the more CO2 absorbed, at higher temperatures CO2 is even outgassed.
What proportion of the oceans does the ‘surface ocean’ represent?
The top 2%
What is the solubility pump?
CO2 dissolved in the top 2% of the ocean by air-sea gas exchange.
What is the ‘physical pump’?
Ocean circulation of CO2 enriched surface waters to the deep (therefore acts most strongly in areas of deep water formation).
What is the ‘chemical pump’?
The chemical reactions of carbon as CO2 dissolves in seawater - without which, the oceans capacity to store CO2 would be reduced by 20-30%.
What is the ‘biological pump’ and how would atmospheric CO2 vary without it?
Photosynthesis, combined with sinking of organic helps uptake of CO2 to the deep ocean. Without this, atmospheric CO2 would probably double.
Put the following processes in order of timescale, from shortest to longest: Chemical Pump, Biological Pump, Physical Pump, Carbon burial, Solubility Pump.
Solubility pump - 1 month Chemical pump - 1 year Biological pump - 1 year Physical pump - 1,000 years Carbon burial - <5,000 years
What might contribute to future sea level rise?
Thermal expansion of waters and melting of sea ice.
What consequence of ocean warming has already been experienced in the North Atlantic?
An increased intensity of hurricanes.
Ocean acidification is likely to negatively affect corals: how?
Acidification leads to a lower saturation state of CaCO3, so less is available to corals who secrete it to form the calcified structures/skeletons necessary for survival. CaCO3 dissolves at a saturation state of less than 1.
Also, Surface warming increases the likelihood of coral
bleaching, the process of whitening coral due to the loss of colour from the expulsion of symbiotic algae living within the coral.
