I think we're going to have to actively manage global ocean circulation as part of integrated management of climate.
Is the North Atlantic a better place to send the crud than the Arctic Ocean? On Aug 8, 8:52 am, Andrew Lockley <[email protected]> wrote: > My further shameless plagiarism from NewScientist > > A > > WITHIN 60 years the Arctic Ocean could be a stagnant, polluted soup. Without > drastic cuts in greenhouse-gas emissions, the Transpolar Drift, one of the > Arctic's most powerful currents and a key disperser of pollutants, is likely > to disappear because of global > warming<http://www.newscientist.com/topic/climate-change> > . > > The Transpolar Drift is a cold surface current that travels right across the > Arctic Ocean from central Siberia to Greenland, and eventually out into the > Atlantic. It was first discovered in 1893 by the Norwegian explorer Fridtjof > Nansen, who tried unsuccessfully to use the current to sail to the North > Pole<http://www.newscientist.com/article/mg19826591.800-climate-scientists...>. > Together with the Beaufort Gyre, the Transpolar Drift keeps Arctic waters > well mixed and ensures that pollution never lingers there for long. > > To better understand the dispersal of pollution in the Arctic Ocean, Ola > Johannessen <http://www.nersc.no/~olam/>, director of the Nansen > Environmental and Remote Sensing Center in Bergen, Norway, and his > colleagues studied the spread of > radioactive<http://www.newscientist.com/topic/nuclear>substances > such as strontium-90 and caesium-137 from nuclear testing, bomb > factories<http://www.newscientist.com/article/mg15621112.400-russias-toxic-shoc...> > and nuclear power <http://www.newscientist.com/topic/nuclear>-plant > accidents. Measurements taken between 1948 and 1999 were plugged into a > high-resolution ocean circulation model and combined with a climate model to > predict Arctic Ocean circulation until 2080. > > Their model confirmed that most pollutants, including pesticide, petroleum > residue and nuclear fallout, are currently washed out into the north > Atlantic by the Transpolar Drift. But perhaps not for much longer. > In a nuclear accident, more radioactive material would be contained in the > Arctic Ocean for much longer > > In a "business-as-usual" scenario, in which atmospheric carbon dioxide > levels double by 2070, Johannessen and his colleagues found that the > Transpolar Drift stops and the Beaufort Gyre, Greenland Current and Gulf > Stream weaken considerably (*Journal of Environmental Radioactivity*, DOI: > 10.1016/j.jenvrad.2009.01.003<http://dx.doi.org/10.1016/j.jenvrad.2009.01.003>). > One reason for this sluggish behaviour is a change in wind patterns driven > by global warming and rapid melting of the Arctic sea ice. > > As a result, pollution takes much longer to disperse in this scenario. Much > of this pollution would congregate along the non-European coastlines of the > Arctic Ocean, the model suggests. > > Jeff Ridley of the Met Office Hadley Centre in Exeter, UK, agrees that > surface circulation in the Arctic Ocean will weaken if sea ice disappears, > but he doubts it will happen quite so fast. He also points out that other > currents in the region would continue to disperse pollutants. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
