Well, on many levels, it will likely prove difficult, and at least quite messy, to get the methane out of the water, so developing techniques to reduce atmospheric levels would surely be useful as a complement.
So, a thought: in recent years, it has been more and more recognized how important halogen chemistry is to the arctic – there are the “bromine explosions” in the arctic spring, for example, and tropospheric ozone plummets to near zero at such times. It is unclear how it happens – but probably exposed sea salt on ice releases the halogens chlorine and bromine. There is a hugely potent reaction of methane with halogens – much more so than the CH4 - OH reaction, for example – that we could possibly exploit if we needed to. Even the halogen impact on ozone itself should be of interest, since the ozone is certainly a factor driving arctic warming in general. And while ecological concerns would immediately make some scream bloody murder, it is interesting, in terms of determining whether there is also a negative aspect to increasing the halogen chemistry for the methane levels themselves, that the aquatic methylotrophy would not be harmed. Indeed, scientists have isolated multiple strains of methyloptrohs in chlorinated drinking water: “It is important to note that most of the Methylobacterium strains isolated from aquatic environments are highly resistant to chlorine (Hiraishi et al., 1995). The chlorine tolerance of methylotrophic bacteria may explain why these organisms frequently occur in human- related environments.” (doi: 10.1099/ijs.0.63319-0 IJSEM January 2005 vol. 55 no. 1 281-287) Anyhow, it's just a thought, that there might be an avenue for dealing with engineering this highly reactive chemistry there, since it is already a natural part of the ecosystem. It is photochemically driven, so it would be done near the surface in the mornings. The tropospheric ozone destruction there is thought to work much like in the stratosphere, with a chain of radical substitutions, and methane is a key factor ending such chains. All best, Nathan Nathan Currier 108 Ellwood Street, #43 New York, NY 10040 401-954-3402 On Oct 7, 9:16 pm, Andrew Lockley <[email protected]> wrote: > As i understand it, nano bubbles don't dissolve much as they get covered in > scum. That's why they last. > > Methane doesn't necessarily come up from deeper sediments when the sun is > up. Warm pulses form when It's hot, but these take time to penetrate into > the permafrost. That's one reason why we might need really aggressive > geoengineering - because we may already have a huge methane pulse in the > post, which we can do absolutely nothing to stop. (That's one good reason > to get this engineering done quickly and not mess about consulting before we > put a balloon on a string!) > > Before we try oxygenation, we would have to check that oxygen depletion > would matter. If methane is being actively produced it would, but fossil > methane isn't going to be much influenced unless it is released and then > dissolves into anoxic waters. I'm not sure this is frequent. > > Further, adding bubbles can entrain methane rich waters and lift them to the > surface, increasing fluxes to the atmosphere. > > Oxygen doesn't act directly on methane, it works by enabling aerobic > metabolism by methanotrophs. Adding ozone would just kill them! > > Seitz bubbles are shallow. Methane rich waters are generally deep. > Therefore, the two techniques don't naturally overlap much. > > So, like most of earth science, It's all just annoyingly complicated. > > A > On Oct 7, 2011 9:37 PM, "Mike MacCracken" <[email protected]> wrote: > > > > > So, would utilizing the nanobubble approach of Seitz to increase albedo > > and limit warming of ocean and lake waters also have the effect of injecting > > enough oxygen to oxidize rising methane bubbles? What about if we did not > > just pump air to make the bubbles but added a hint of some chemical compound > > (like ozone), would the chemical oxidation of rising methane bubbles be > > faster/fast enough? I presume most methane comes out when the Sun is up, so > > might we be able to achieve a win-win situation? For when there is no > > sunlight and we have sea ice present, does the methane accumulate before the > > ice and in that situation is there enough time for organisms of various > > types to utilize the methane for food? > > > I ask in that going around making nanobubbles is likely, if not easy, > > nonetheless a lot easier than laying out various plastic layers, etc. > > > Mike MacCracken > > > On 10/7/11 3:06 PM, "Andrew Lockley" <[email protected]> wrote: > > > Group: pls excuse the hard-to-follow thread jumping... > > > Methane from lakes comes mainly from the shoreline, where there is active > > thawing of frozen soils, and a very short pathway for rising bubbles - so > > dissolution is low. > > > In the sea or ocean, pathways are longer and often not straight (especially > > for smaller bubbles) due to wave mixing. > > > I'm not clear that we have any reliable indicators at present as to the > > proportion of marine methane excursions from bubbles and from simple > > diffusion from the sea surface. My guess is that bubbles are dominant, but > > likely much less so than for lakes as explained above. > > > If I'm right, recovering some bubbles at the sea floor may not make a lot > > of difference, as bubble size matters more than gas volume - so leaks could > > actually make things worse than without recovery. In fact, in my recent > > draft paper I propose using re-bubbling equipment to adjust the size of > > bubbles without recovering the methane. > > > I agree we cannot at this stage rule out an end permian event. It terrifies > > me. > > > A > > On Oct 7, 2011 7:45 PM, "Stuart Strand" <[email protected]> wrote: > > > And I know nearly nothing about marine engineering, so take my skepticism > > with a grain of salt. > > > Again, dissolved methane is likely to be oxidized in the water column and > > oxygen is unlikely to be exhausted by the oxidation of dissolved methane. > > Rapid release of methane in bubbles is possible in shallow water, and in > > arctic lakes ebullition has been shown to be the major pathway of release; > > but without exhausting oxygen in the water column. If you can devise a way > > to trap those bubbles, great! > > > But will it take the beginning of a permean-like extinction to be allowed > > to test? > > > = Stuart = > > > Stuart E. Strand > > 490 Ben Hall IDR Bldg. > > Box 355014, Univ. Washington > > Seattle, WA 98105 > > voice 206-543-5350 <tel:206-543-5350> , fax 206-685-9996 <tel:206-685-9996> > > > skype: stuartestrand > >http://faculty.washington.edu/sstrand/ > > > *From:* Stephen Salter [mailto:[email protected] <[email protected]>] > > *Sent:* Friday, October 07, 2011 9:44 AM > > *To:* Stuart Strand > > *Cc:* Veli Albert Kallio; John Nissen; [email protected]; > > [email protected]; [email protected]; Peter Wadhams; Michel > > Halbwachs; [email protected]; [email protected]; > > Geoengineering FIPC; Matti Lappalainen; Risto Isomaki; Esko Pettay > > *Subject:* Re: [geo] Re: Arctic methane workshop: 15-16 October - Methane > > vents > > > Stuart > > > This topic arose because Albert said that plastic film would produce anoxic > > conditions in the sea bed. The questions is if we leave methane and oxygen > > together in the ooze for a long time one or other will get depleted. If > > there is methane coming up I thought that it would mean that it had used up > > all the oxygen. If it had then a plastic film would not be making things > > any worse. > > > I do not claim to know anything about chemistry or biology but I expect you > > all have realized this already. > > > Stephen > > > Emeritus Professor of Engineering Design > > Institute for Energy Systems > > School of Engineering > > Mayfield Road > > University of Edinburgh EH9 3JL > > Scotland > > Tel +44 131 650 5704 <tel:%2B44%20131%20650%205704> > > Mobile 07795 203 195 > >www.see.ed.ac.uk/~shs<http://www.see.ed.ac.uk/~shs> > > > On 06/10/2011 21:22, Stuart Strand wrote: > > Methane oxidation in the ocean occurs aerobically and anaerobically (with > > sulfate as the electron acceptor). Dissolved methane is oxidized before > > reaching surface waters. In shallow waters methane in bubbles easily > > escapes microbial oxidation. > > > = Stuart = > > > Stuart E. Strand > > 490 Ben Hall IDR Bldg. > > Box 355014, Univ. Washington > > Seattle, WA 98105 > > voice 206-543-5350 <tel:206-543-5350> , fax 206-685-9996 <tel:206-685-9996> > > > skype: stuartestrand > >http://faculty.washington.edu/sstrand/ > > > *From:* [email protected] [ > > mailto:[email protected] <[email protected]>] > > *On Behalf Of *Stephen Salter > > *Sent:* Thursday, October 06, 2011 7:43 AM > > *To:* Veli Albert Kallio > > *Cc:* John Nissen; [email protected]; [email protected]; > > [email protected]; Peter Wadhams; Michel Halbwachs; > > [email protected]; [email protected]; Geoengineering > > FIPC; Matti Lappalainen; Risto Isomaki; Esko Pettay > > *Subject:* Re: [geo] Re: Arctic methane workshop: 15-16 October - Methane > > vents > > > Albert > > > I am vague about release patterns and my ideas are based in the > > echo-sounder images in the Shakhova paper. If you want to use a cupola hood > > of any size in 50 metres of water you would have to know about wave loads > > which will still be present at that depth. > > > You mention 10 metre wide plastic strip. I think that we can go up to > > widths of 1500 metres in lengths of 3000 metres. I will try to circulate > > engineering drawings of the tool to make the sheet and the equipment to > > deploy it before the meeting. > > > I am glad to hear that we can get oxygen under a sheet if we need to but > > still puzzled about why the methane has not gobbled what was there before we > > laid down the sheet. > > > Stephen > > > Emeritus Professor of Engineering Design > > Institute for Energy Systems > > School of Engineering > > Mayfield Road > > University of Edinburgh EH9 3JL > > Scotland > > Tel +44 131 650 5704 <tel:%2B44%20131%20650%205704> > > Mobile 07795 203 195 > >www.see.ed.ac.uk/~shs<http://www.see.ed.ac.uk/%7Eshs> > > > On 06/10/2011 13:42, Veli Albert Kallio wrote: > > > *Hi Steven, > > * > > I think what needs to be decided is the approach: > > > 1) are we trying to address spot-like emissions, or, > > 2) methane haze arising smoothly from vast area of sea bed. > > > No. 1 can be addressed by a cupola-like hood over the spot from where the > > gases are removed > > No. 2 can be addressed by a slightly V-shapedly folded straps of plastic > > where gas accummulates to the tip of upside down V-fold and steams towards > > the rising end of strap where it is collected. I think flatbed sheet probaly > > oozes gas out from over the edges, or one ends up with a controured sheet of > > multiple gas bubbles; this becomes increasingnly unstable system as gas > > accummulates. I favour passive systems where gas constantly streams upwards > > to the collection point. I also think that I roll could be unwound from the > > back of ship. > > > However, just 1 km2 area with 10 metre strap plastic would require 100 km > > of sailing back and forth before all is covered. If 100 km x 100 km box was > > covered from ESAS by sheet 100,000 km of 100 metre strap would be needed. > > Anoxic conditions can be addressed by say using 2kW Mixox units that could > > blow 1,000,000 m3 of oxygenated air under the plastic sheet to aerate the > > plastic covered ocean. Mixox would suck oxygen rich surface air and blow it > > through tube to beneath the plastic sheet. As methane bubbles are lighter > > than even oxygenated and less saline surface air, the bubbles would still > > rise normally through the treated water until they reach the collecting > > sheet. > > > We proposed with Matti Lappalainen at the World Water Week in 2006 to > > oxygenate the Amazon river estuary during the low oxygen drought season with > > 40,000 Mixox units for 100 km section of Amazon in our paper "Preparing the > > Amazon Ecosystems for the Changing Climate". Mixox systems are deployed in > > 27 km2 sea floor oxygenation pilot project in the Baltic Sea in Finland and > > another 2.7 km2 in Sweden to reduced the anoxic conditions arising from > > warmer temperatures, phosphathe leaks and organic material load. > > ... > > read more » -- 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]. 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