Andrew--Greg is right--and warming of ocean near surface would also force CO2 out, so maybe do at high latitudes where it is cold and encourage marine life.
Mike On 1/14/09 7:25 PM, "Andrew Lockley" <[email protected]> wrote: > > Any outgassing of the deep ocean water when it rose to the surface > would only release gases added during the aeration process. Unless > the existing ocean water was supersaturated, then there shouldn't be > any additional outgassing. I don't have the expertise to advise > whether there are supersaturated CO2 layers in the ocean. > > A > > 2009/1/14 Greg Rau <[email protected]>: >> Perhaps I've missed something, but if you are advocating increased >> ventilation of the subsurface ocean, this water is not only nutrient rich, >> but is is also supersaturated in CO2 (relative to air). Natural ocean >> upwelling is a huge CO2 source for the atmosphere. So unless you can show >> that stimulation of biological CO2 fixation (via the nutrient upwelling) >> more than offsets the upwelled CO2 degassing to the atmosphere, what's the >> point? >> -Greg Rau >> >> >> >>> A simple way to achieve this would be to force air down into deep >>> pipes and allow it to bubble to the surface. The same principle is >>> used in fishtanks to create upwelling water and increase the surface >>> area for gaseous exchange. There's a tradeoff between little bubbles >>> (for gaseous exchange) and big bubbles (to force mixing). >>> >>> Flow tubes would probably be necessary to create a defined upwelling >>> column of water. These tubes would provide a reasonably good mount >>> for a wind turbine or sea turbine, provided they could be anchored to >>> the sea bed. The most obvious engineering problem I can think of is >>> stability and resonances. >>> >>> What do other people think? >>> >>> A >>> >>> 2009/1/13 John Nissen <[email protected]>: >>>> >>>> Hi all, >>>> >>>> Could there be a case for geoengineering to increase sea "ventilation" >>>> and >>>> thereby increase CO2 absorption by the sea? (I'm thinking of those >>>> millions >>>> of wave-powered tubes suggested by Chris Rapley and James Lovelock to >>>> bring >>>> deep cool water to the surface.) >>>> >>>> http:// www. >>>> guardian.co.uk/environment/2009/jan/12/sea-co2-climate-japan-environment >>>> >>>> --- >>>> >>>> >>>> Sea absorbing less CO2, scientists discover >>>> >>>> David Adam, environment correspondent >>>> The Guardian, Monday 12 January 2009 >>>> Article history >>>> >>>> Scientists have issued a new warning about climate change after >>>> discovering >>>> a sudden and dramatic collapse in the amount of carbon emissions >>>> absorbed by >>>> the Sea of Japan. >>>> >>>> The shift has alarmed experts, who blame global warming. >>>> >>>> The world's oceans soak up about 11bn tonnes of human carbon dioxide >>>> pollution each year, about a quarter of all produced, and even a slight >>>> weakening of this natural process would leave significantly more CO2 in >>>> the >>>> atmosphere. That would require countries to adopt much stricter >>>> emissions >>>> targets to prevent dangerous rises in temperature. >>>> >>>> Kitack Lee, an associate professor at Pohang University of Science and >>>> Technology, who led the research, says the discovery is the "very first >>>> observation that directly relates ocean CO2 uptake change to ocean >>>> warming". >>>> >>>> He says the warmer conditions disrupt a process known as "ventilation" - >>>> the >>>> way seawater flows and mixes and drags absorbed CO2 from surface waters >>>> to >>>> the depths. He warns that the effect is probably not confined to the Sea >>>> of >>>> Japan. It could also affect CO2 uptake in the Atlantic and Southern >>>> oceans. >>>> >>>> "Our result in the East Sea unequivocally demonstrated that oceanic >>>> uptake >>>> of CO2 has been directly affected by warming-induced weakening of >>>> vertical >>>> ventilation," he says. Korea argues that the Sea of Japan should be >>>> renamed >>>> the East Sea, because it says the former is a legacy of Japan's military >>>> expansion in the region. >>>> >>>> Lee adds: "In other words, the increase in atmospheric temperature due >>>> to >>>> global warming can profoundly influence the ocean ventilation, thereby >>>> decreasing the uptake rate of CO2." >>>> >>>> Working with Pavel Tishchenko of the Russian Pacific Oceanological >>>> Institute >>>> in Vladivostok, Lee and his colleague Geun-Ha Park used a cruise on the >>>> Professor Gagarinskiy, a Russian research vessel, last May to take >>>> seawater >>>> samples from 24 sites across the Sea of Japan. >>>> >>>> They compared the dissolved CO2 in the seawater with similar samples >>>> collected in 1992 and 1999. The results showed the amount of CO2 >>>> absorbed >>>> during 1999 to 2007 was half the level recorded from 1992 to 1999. >>> >>>> >>>> >>>> Crucially, the study revealed that ocean mixing, a process required to >>>> deposit carbon in deep water, where it is more likely to stay, appears >>>> to >>>> have significantly weakened. >>>> >>>> Announcing their results in the journal Geophysical Research Letters, >>>> the >>>> scientists say: "The striking feature is that nearly all anthropogenic >>>> CO2 >>>> taken up in the recent period was confined to waters less than 300 >>>> metres in >>>> depth. The rapid and substantial reduction ... is surprising and is >>>> attributed to considerable weakening of overturning circulation." >>>> >>>> Corinne Le Quéré, an expert in ocean carbon storage at the University of >>>> East Anglia, said: "We don't think the ocean is just going to completely >>>> stop taking our carbon dioxide emissions, but if the effect weakens then >>>> it >>>> has real consequences for the atmosphere." >>>> >>>> --- >>>> >>>> >>>> Cheers, >>>> >>>> John >>>> >>>>> >>>> >>> >>>> >> > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
