Interesting‹so are you in accord with the original result at http://zeenews.india.com/news/eco-news/arctic-sea-ice-depletion-to-result-in -rise-of-co2-in-atmosphere_1474406.html
Mike On 9/24/14 5:29 PM, "Ken Caldeira" <[email protected]> wrote: > My sense is that brine rejection / melting of sea ice acts as a rectifier > increasing vertical stability in the upper ocean, and that a loss of sea ice > would decrease vertical stability in the upper ocean and thus increase > vertical mixing. > > The seasonal sea-ice cycle acts like a rectifier, with brine during ice > formation sinking to the pycnocline at the base of the mixed-layer while > low-density water from melting sea ice stays on the surface. > > In model simulations without brine rejection from sea ice, there would be > much less vertical stability of the water column and much less large scale > convection and much more CFC (and CO2) uptake. > > Please see the attached paper. > > http://onlinelibrary.wiley.com/doi/10.1029/98GL00336/pdf > > > > > _______________ > 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 Thu, Sep 25, 2014 at 9:58 AM, Mike MacCracken <[email protected]> wrote: >> 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] >> <http://[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] <http://[email protected]> >>> <mailto:[email protected]> >>> cell: 928 451 4455 <tel:928%20451%204455> >>> >>> >>> >>> >>> From: [email protected] >>> <http://[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] >>> <http://[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] >>> <http://[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 <tel:%2B1%20650%20704%207212> [email protected] >>> <http://[email protected]> >>> http://dge.stanford.edu/labs/caldeiralab >>> https://twitter.com/KenCaldeira >>> >>> Assistant: Dawn Ross <[email protected] >>> <http://[email protected]> > >>> >>> >>> On Wed, Sep 24, 2014 at 5:45 AM, Rau, Greg <[email protected] >>> <http://[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] >>> <http://[email protected]> [[email protected] >>> <http://[email protected]> ] on behalf of Andrew Lockley >>> [[email protected] <http://[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 >>> -rise-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.
