As I understand it, the sulphur is mainly in the gas phase, whereas the BC is necessarily particulate. Therefore a cyclonic, electrostatic or conventional porous filter would probably do the trick.
A On Sep 14, 2012 8:49 PM, "John Nissen" <johnnissen2...@gmail.com> wrote: > Hi Mike, > > Could there be a method of selective filtering of coal-fired power > stations, such that the cooling aerosol (or SO2 precursor) is allowed into > the troposphere while the black carbon is removed? > > Cheers, > > John > > --- > > On Tue, Sep 11, 2012 at 7:15 PM, Mike MacCracken <mmacc...@comcast.net>wrote: > >> Hi Stephen—I would think that Chinese sulfate (like tropospheric >> sulfate from virtually anywhere) would contribute to cloud and free air >> brightening, so a cooling influence (especially when that sulfate is above >> the dark Pacific Ocean). Now, in that coal plants put out more than pure >> SO2, there might well be some components (such as black carbon) that would >> exert a strong warming influence, especially if they are carried far enough >> to deposit on snow and/or ice during the sunny half of the year in the >> Arctic. For net effect, there is need for much more analysis than I have >> seen. >> >> On limiting heat reaching the Arctic Ocean, there have been suggestions >> to even build a dam across the Bering Strait—as long ago as the mid-20th >> century (though I think then it was with the intent to warm the Arctic). My >> guess on the kelp idea is that the sunny part of the year is not long >> enough for that approach to be all that practical (not only is the sunny >> part of the year short, but the sun angle is often not helpful). And sea >> ice is typically only a few meters thickness, so no where near 30 m. >> >> Mike >> >> >> >> On 9/11/12 12:48 PM, "Stephen Salter" <s.sal...@ed.ac.uk> wrote: >> >> >> Mike >> >> Do you think that the higher levels of SO2 from Chinese coal burning >> could account for some of the increase in Arctic temperatures? >> >> Another thought for your list might be to increase the drag of water >> flowing in through the Bering Strait. In summer kelp grows at an amazing >> rate but not below about 30 metre water depth because of the shortage of >> light. The net flow is 800,000 m3 a second and it will be warmer than >> polar water so a small velocity reduction makes a big difference. What if >> we put strong ropes moored at 30 metres to give them kelp a foot hold? If >> kelp gets scraped off by floating ice it will can grow again. Does ice >> reach down to 30 metres? >> >> Stephen >> >> On 11/09/2012 18:05, Mike MacCracken wrote: >> >> >> >> Re: [geo] Coupled Model Intercomparison Project 5 (CMIP5) simulations of >> climate following volcanic eruptions In my view, this is just why >> geoengineering efforts to cool the Arctic should consider as approaches: >> (a) spring-summer only injection of the appropriate sulfur compound >> (whatever will lead to sulfates) into the LOWER stratosphere or free >> troposphere, (b) cloud brightening in region or over currents carrying heat >> into the region, (c) approaches to brighten the surface albedo (e.g., >> microbubbles) in or near the region, and, perhaps, (d) approaches to reduce >> cirrus that are reducing IR loss. >> >> >> Parallel to these efforts, we should also be working to limit emissions >> of substances that amplify Arctic warming above and beyond the >> amplification that happens due to natural processes, so black carbon from >> sources in and near the region, etc. >> >> Mike >> >> >> >> >> On 9/11/12 5:03 AM, "Stephen Salter" <s.sal...@ed.ac.uk> wrote: >> >> >> >> >> Hi All >> >> Six out of the eight models in the Driscoll et al paper show near >> surface-warming in Arctic winters following volcanic eruptions. This is in >> line with figure 2a the Jones Hayward Boucher Robock 2010 paper in >> Atmospheric Chemistry and Physics. The obvious mechanisms are blanketing of >> outgoing radiation and side-scatter of high solar rays that might have >> missed the polar regions. Given the concerns about the loss of Arctic ice >> and increased methane release we will have to be very careful not to let >> any geo-engineering sulphur that we inject at low latitudes reach the >> Arctic in winter. >> >> Stephen >> >> On 10/09/2012 16:52, Simon Driscoll wrote: >> >> >> >> >> >> >> Dear all, >> >> the published version (no longer PiP) is now available here: >> >> http://www.agu.org/pubs/crossref/2012/2012JD017607.shtml >> >> Warm regards, >> >> Simon >> >> >> >> >> >> ________________________________________________ >> >> Simon Driscoll >> Atmospheric, Oceanic and Planetary Physics >> Department of Physics >> University of Oxford >> >> Office: 01865 272930 >> Mobile: 07935314940 >> >> http://www2.physics.ox.ac.uk/contacts/people/driscoll >> >> http://www.geoengineering.ox.ac.uk/people/who-are-we/simon-driscoll/ >> >> >> >> >> >> >> ------------------------------ >> >> *From:* geoengineering@googlegroups.com [geoengineering@googlegroups.com] >> on behalf of Andrew Lockley [andrew.lock...@gmail.com] >> *Sent:* 14 August 2012 02:06 >> *To:* geoengineering >> *Subject:* [geo] Coupled Model Intercomparison Project 5 (CMIP5) >> simulations of climate following volcanic eruptions >> >> >> >> >> >> http://www.agu.org/pubs/crossref/pip/2012JD017607.shtml >> >> >> The ability of the climate models submitted to the Coupled Model >> Intercomparison Project 5 (CMIP5) database to simulate the Northern >> Hemisphere winter climate following a large tropical volcanic eruption is >> assessed. When sulfate aerosols are produced by volcanic injections into >> the tropical stratosphere and spread by the stratospheric circulation, it >> not only causes globally averaged tropospheric cooling but also a localized >> heating in the lower stratosphere, which can cause major dynamical >> feedbacks. Observations show a lower stratospheric and surface response >> during the following one or two Northern Hemisphere (NH) winters, that >> resembles the positive phase of the North Atlantic Oscillation (NAO). >> Simulations from 13 CMIP5 models that represent tropical eruptions in the >> 19th and 20th century are examined, focusing on the large-scale regional >> impacts associated with the large-scale circulation during the NH winter >> season. The models generally fail to capture the NH dynamical response >> following eruptions. They do not sufficiently simulate the observed >> post-volcanic strengthened NH polar vortex, positive NAO, or NH Eurasian >> warming pattern, and they tend to overestimate the cooling in the tropical >> troposphere. The findings are confirmed by a superposed epoch analysis of >> the NAO index for each model. The study confirms previous similar >> evaluations and raises concern for the ability of current climate models to >> simulate the response of a major mode of global circulation variability to >> external forcings. This is also of concern for the accuracy of >> geoengineering modeling studies that assess the atmospheric response to >> stratosphere-injected particles.Received 13 February 2012; accepted 24 July >> 2012. >> -- >> You received this message because you are subscribed to the Google >> Groups "geoengineering" group. >> To post to this group, send email to geoengineering@googlegroups.com. >> To unsubscribe from this group, send email to >> geoengineering+unsubscr...@googlegroups.com. >> 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. >> To post to this group, send email to geoengineering@googlegroups.com. >> To unsubscribe from this group, send email to >> geoengineering+unsubscr...@googlegroups.com. >> 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. >> To post to this group, send email to geoengineering@googlegroups.com. >> To unsubscribe from this group, send email to >> geoengineering+unsubscr...@googlegroups.com. >> 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. >> To post to this group, send email to geoengineering@googlegroups.com. >> To unsubscribe from this group, send email to >> geoengineering+unsubscr...@googlegroups.com. >> 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. > To post to this group, send email to geoengineering@googlegroups.com. > To unsubscribe from this group, send email to > geoengineering+unsubscr...@googlegroups.com. > 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. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
