Hi all, There are two cycles to consider: the carbon and heat. The paper that Renaud refers to, by Zhou and Flynn [1], suggests a means to incrementally increase the downwelling in the GIN (Greenland Iceland Norwegian sea), in order to capture more CO2. This downwelling is a thermohaline circulation. Since this additional water is cooled by the atmosphere to make it sink to the ocean deep, the atmosphere is correspondingly warmed (though some of the cooling will be by radiation into space). However, in the longer term, the removal of CO2 leads to less greenhouse gas warming of the atmosphere. Their preferred method is by pumping ocean water onto the surface of sea ice in winter.
However Albert points out that the thickening of sea ice would slow melt in spring, so that more sunlight is reflected, having an immediate net cooling. If there is sufficient thickness, the ice could last through the summer, forming multiannual ice for the next year. Thus we have a number of processes at play. Some care is needed to determine the net short and long-term effects of pumping water onto sea ice in winter. We should consider the cases when the water is saline (from the ocean) and fresh (e.g. from Russian rivers). Note that the recent suggestion of a widely reported article in Nature [2], that CO2 emissions reduction could save the sea ice (and hence polar bears), does not take into proper account the positive feedbacks and it assumes climate responds immediately to CO2 level change, which is absurd. Cheers, John [1] http://www.springerlink.com/content/pt637l16gt5r7023/fulltext.pdf [2] http://www.nature.com/nature/journal/v468/n7326/full/nature09653.html --- On Thu, Dec 9, 2010 at 12:10 PM, Renaud-KdeR <[email protected]> wrote: > Dear Geoengineering Group, > > This reminds me the local scale geoengineering idea by Peter Flynn and > S. Zhou of restoring the northern THC with barge-operated ice making > machines... > This will also modify albedo... > > Regards > Renaud de_RICHTER > > GEOENGINEERING DOWNWELLING OCEAN CURRENTS: A COST ASSESSMENT > S. ZHOU and P. C. FLYNN > Climatic Change, 2005, 71 (1-2), p203-220, DOI: 10.1007/ > s10584-005-5933-0 > > Abstract. Downwelling ocean currents carry carbon into the deep ocean > (the solubility pump), and > play a role in controlling the level of atmospheric carbon. The > formation of North Atlantic Deep > Water (NADW) also releases heat to the atmosphere, which is a > contributor to a mild climate in > Europe. One possible response to the increase in anthropogenic carbon > in the atmosphere and to the > possible weakening of the NADW is modification of downwelling ocean > currents, by an increase in > carbon concentration or volume. This study assesses the costs of seven > possible methods of modifying > downwelling currents, including using existing industrial techniques > for exchange of heat between > water and air. Increasing carbon concentration in downwelling currents > is not practical due to the high > degree of saturation of high latitude surface water. Two of the > methods for increasing the volume of > downwelling currents were found to be impractical, and four were too > expensive to warrant further > consideration. Formation of thicker sea ice by pumping ocean water > onto the surface of ice sheets is > the least expensive of the methods identified for enhancing > downwelling ocean currents. Modifying > downwelling ocean currents is highly unlikely to ever be a competitive > method of sequestering carbon > in the deep ocean, but may find future application for climate > modification. > > On 8 déc, 20:48, Veli Albert Kallio <[email protected]> wrote: > > Dear Geoengineering Group, > > > > For over a year now I have concentrated on occasional information relays > to Climateintervention rather than on the more demanding creative sides, due > to my other climate-related projects. However, I think this observation is > important sea ice aspect to be considered. > > > > I would like to draw an observation and suggest a geoengineering > application from the following statement by NSIDC on 6th Dec 2010: > > > > "As temperatures drop in autumn, open water areas on the Arctic coastal > seas quickly refreeze. After this rapid increase in ice extent during > October, ice growth slows in November. This November, ice extent over the > entire Arctic grew at an average rate of 74,000 square kilometres per day > (28,600 miles per day), which is slower than average. However, local weather > conditions kept ice extent very low in some locations, contributing to the > low extent for the month." NSIDC November Arctic Sea Ice Report. 6th Dec. > 2010 > > > > From the above NSIDC statement which says that the sea ice growth is very > rapid in October, but contrarily slows down in November which is colder, I > suggest that floating cables or levees, even platforms, could act as > "seeding points" to fasten the seasonal growth of the Arctic Ocean's sea > ice. This, in particular, is important as all climate solutions that rely or > require a future presence of multi-year sea ice are doomed. However, sea ice > generating schemes that rely on seasonal ice growth to be enhanced will be > more successful. > > > > Perhaps this overcomes the earlier shortcomings of the suspension cabling > systems blocking the southward movement of sea ice in the Nares Straight > (Ellesemere - Hans Island - Greenland) or on the straights on the Queen > Elizabeth Islands (that bring ice to the NW Passage). Such schemes will fail > the moment the sea ice has started to melt on the north side of the sea ice > blocks. As we saw the sea ice disintegrating and opening seas on the North > Pole in July, August and September we should plan for a total sea ice loss > situation. > > > > NSIDC indicates clearly that all multi year ice has gone and now we are > down to thin, if not single season, ice. But either as a fixed or > free-floating cables or platforms could seed ice formation around themselves > and stabilise the sea surface for sea ice growth. Floating platforms and > levees would pose least risk for wildlife, floating mesh wire nets or cables > could prove more problematic for wild life. > > > > Floating net for ship would cause issues, but if we want sea ice on the > North Pole it will have to happen at the expense of some shipping. However, > by area management such a usage issues can, and must be avoided. This is > nothing more than the cloud seeding and rain harvesting to provided surfaces > that then start build up ice around themselves. > > > > If the sea ice could be introduced 4 weeks earlier, say from November to > October in higher seas, this would mean a thicker ice for the spring and > more sunlight reflection for the following season. The sea ice creation will > be enhanced by this. > > > > Also, as a refresher of some earlier discussions in the past, please note > that in the cold and dark autumn conditions (just like in seas around > Antarctica), the breaking-up of sea ice itself tends to seed the rapid ice > area growth. These conditions are much stronger in Antarctica due to the > reverse arrangement of continents to ocean, but can be seen also at times > working also in the Arctic Ocean. > > > > In the warming-up of the spring season, the effect of sea ice break up is > the opposite (as ocean has been mopping up heat). Russian government and the > Far East Shipping Company (FESCO) calls this kind of sea ice manipulation to > make the sea ice melt faster (sea ice demolition) as "ice chipping" and > these operations are carried out at Amurskaya Bay area every year to cut sea > ice off following coastline by driving ice breaker along precise coastal > margins in suitable wind conditions for loosened ice to escape to a > warmed-up ocean to disappear and let the albedo to take over the better > weather. > > > > Please give comments, I would like to see our group turning up new ideas > like in the heydays in the past. > > > > Kind regards, > > > > Albert > > -- > 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]<geoengineering%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/geoengineering?hl=en. > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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