However, briny water does increase vertical mixing (and sea ice forms not only in the Arctic, but in the far northern Atlantic, etc.), countering the effects of stratification that would limit vertical exchange of CO2.
Mike On 9/23/14 7:34 PM, "Peter Flynn" <[email protected]> wrote: > North Atlantic Deep Water (NADW) is thought to primarily form in the open > ocean and does not originate from the brine coming off the bottom of sea ice. > > Peter > > Peter Flynn, P. Eng., Ph. D. > Emeritus Professor and Poole Chair in Management for Engineers > Department of Mechanical Engineering > University of Alberta > [email protected] <mailto:[email protected]> > cell: 928 451 4455 > > > > > From: [email protected] [mailto:[email protected]] > On Behalf Of Mike MacCracken > Sent: September-23-14 6:32 PM > To: Ken Caldeira; Greg Rau > Cc: Andrew Lockley; Geoengineering; [email protected] > Subject: Re: [geo] Arctic sea ice depletion to result in rise of CO2 in > atmosphere | Zee News > > In my reading, the wording was very confusing. Reading more carefully, it > seemed to me that they were saying that there will be less CO2 in the ocean as > a result of melting back of the sea ice. An open Arctic with no sea ice > formation would imply less down-welling due to not forming dense brine > pockets, so one mechanism would be a consequence of that, and another might be > due to the greater stability of the ocean in the warm season. I did not read > the paper, but, once I got past some unclear wording, the sign sort of made > sense. > > Mike > > > On 9/23/14 1:52 PM, "Ken Caldeira" <[email protected]> wrote: > Agree with Greg. > > If there is any net effect of this process at all (relative to the no-ice > situation) then quantitatively it must be tiny tiny tiny. > > If the alkalinity represented by the Ca2+ in the CaCO3 was in the surface > ocean with no ice, that would tend to draw CO2 into the ocean. > > > _______________ > Ken Caldeira > > Carnegie Institution for Science > Dept of Global Ecology > 260 Panama Street, Stanford, CA 94305 USA > +1 650 704 7212 [email protected] > http://dge.stanford.edu/labs/caldeiralab > https://twitter.com/KenCaldeira > > Assistant: Dawn Ross <[email protected]> > > > On Wed, Sep 24, 2014 at 5:45 AM, Rau, Greg <[email protected]> wrote: > "A new study has revealed that Arctic Sea ice helps remove carbon dioxide from > the atmosphere and its depletion would result in an increase of atmospheric > concentration of the gas." [?!] > > How does removing CO2 from air increase air CO2 concentrations? Anyway, can > believe that CaCO3 precipitates and CO2 is generated as seawater freezes and > brine is formed: Ca(HCO3)2aq ---> CaCO3s + CO2g + H2O. But whether the CO2 is > then subducted with the sinking brine or degasses to the atmosphere would seem > critical to the air/ocean CO2 budget. That some CaCO3s is entrained in the the > ice seems logical, but how the preceding reaction is reversed to consume this > carbonate and CO2 is unclear. There would need to be a way to concentrate CO2 > to generate H2CO3 to then consume the CaCO3s to (re)make Ca(HCO3)2aq. How > does that happen? Anyway, if it does happen this would seem to offer a > new explanation for glacial/ interglacial CO2 variations, not to mention a new > method of modern day CDR - bomb sea ice sheets with limestone particles. > Beneficial "chemtrails on ice" ;-) > Greg > > > > From: [email protected] [[email protected]] on > behalf of Andrew Lockley [[email protected]] > Sent: Tuesday, September 23, 2014 4:56 AM > To: geoengineering > Subject: [geo] Arctic sea ice depletion to result in rise of CO2 in atmosphere > | Zee News > > http://zeenews.india.com/news/eco-news/arctic-sea-ice-depletion-to-result-in-r > ise-of-co2-in-atmosphere_1474406.html > > Arctic sea ice depletion to result in rise of CO2 in atmosphere Last Updated: > Tuesday, September 23, 2014 - 12:38 > > Washington: A new study has revealed that Arctic Sea ice helps remove carbon > dioxide from the atmosphere and its depletion would result in an increase of > atmospheric concentration of the gas. > > Dorte Haubjerg Sogaard, PhD Fellow, Nordic Center for Earth Evolution, > University of Southern Denmark and the Greenland Institute of Natural > Resources, Nuuk, said that if their results are representative, then sea ice > plays a greater role than expected, and we should take this into account in > future global CO2 budgets. > > The researchers said that they have long known that the Earth's oceans are > able to absorb huge amounts of CO2. But they also thought that this did not > apply to ocean areas covered by ice, because the ice was considered > impenetrable. However, this is not true, as the new research shows that sea > ice in the Arctic draws large amounts of CO2 from the atmosphere into the > ocean. > > Sogaard said that the chemical removal of CO2 in sea ice occurs in two phases. > First crystals of calcium carbonate are formed in sea ice in winter. During > this formation CO2 splits off and is dissolved in a heavy cold brine, which > gets squeezed out of the ice and sinks into the deeper parts of the ocean. > Calcium carbonate cannot move as freely as CO2 and therefore it stays in the > sea ice. In summer, when the sea ice melts, calcium carbonate dissolves, and > CO2 is needed for this process. Thus, CO2 gets drawn from the atmosphere into > the ocean -and therefore CO2 gets removed from the atmosphere. > > ANI -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
