A more efficient solution is to use ice breakers in cold weather. Exposing the sea surface loses heat and quickly forms new ice; fracture energy is small if pieces are large. Lifting ice chunks onto the unbroken ice will help ensure the channel stays clear. The approach has to consider wind drift, as broken multi year ice can be cleared into warm water by wind, leaving the sea exposed in summer
On Sun, 28 Jul 2019, 17:59 Peter Flynn, <[email protected]> wrote: > I think the key difference here is the “sink” for the rejected heat. In > the case of spray or low lift pumping on to the surface of existing ice, > heat is rejected to the atmosphere. One presumes that with an ice forming > submarine the latent heat of crystallization is rejected into the ocean. > > > > One caution would be to not reduce North Atlantic Deep Water (NADW), the > downwelling offset of the Gulf Stream. By memory, this flow is about 15 > Sverdrups. Salinty plus low temperature drives the downwelling. In a first > level analysis, making submarine ice would enhance salinity (by rejection > of brine from the mostly fresh water formed ice) but increase temperature. > The former would almost certainly be the greater impact: as a reviewer of > our paper commented, “salinity trumps temperature”. > > > > “Ice cannons” to make a spray were used to quickly build ice drilling > platforms anchored in the shallow Beaufort Sea; the push was “quick”. But > this is energy intensive. The standard ice thickening technique for ice > bridges/roads in the north is simply low lift pumping of water to the > surface of existing ice, exposing water to ambient air temperature and > avoiding the insulating effect of the ice sheet itself when incremental ice > forms at the bottom of the ice sheet. > > > > Forming ice in the Arctic has many merits. First, we know the former > extent of sea ice, so we have a sense of how much is needed. Second, if > unanticipated adverse effects are identified, the process can be > immediately stopped. > > > > One key research question is the disposition of salt when sea water is > pumped on the surface of ice: does a brine migrate through microchannels in > the ice (as occurs when ice forms at the bottom of an ice sheet), or is it > trapped in the surface ice. I regret that I do not have any resources to do > a simple test of this, as outline in the attachments. > > > > Peter > > > > *From:* [email protected] <[email protected]> *On > Behalf Of *Renaud de RICHTER > *Sent:* Sunday, July 28, 2019 5:43 AM > *To:* Andrew Lockley <[email protected]>; geoengineering < > [email protected]> > *Cc:* Greg Rau <[email protected]>; Peter Flynn <[email protected]> > *Subject:* Re: [geo] Dezeen: Iceberg-making submarine aims to tackle > global warming by re-freezing the Arctic > > > > This is just a more expensive variant of the papers from Songjian Zhou > and Peter C. Flynn, they use submarines instead of snow-guns. > > Zhou, S., & Flynn, P. C. (2005). Geoengineering downwelling ocean > currents: a cost assessment > <https://www.researchgate.net/profile/Peter_Flynn/publication/226572639_Geoengineering_Downwelling_Ocean_Currents_A_Cost_Assessment/links/00b7d51ae05c2c75ae000000/Geoengineering-Downwelling-Ocean-Currents-A-Cost-Assessment.pdf>. > *Climatic change*, *71*(1-2), 203-220. > > > > They don't produce "icebergs", but "sea ice". > > Might be better not to fill all the space, but to let holes in between the > hexgonal sea-ice puzzle structure, in order to enhance longwave radiation > from the ocean to the space, as ice acts as an insulator. > > > > *CDR *=> Zhou, S., & Flynn, P. C. Can the solubility pump be enhanced? > <https://www.researchgate.net/profile/Peter_Flynn/publication/228842887_Can_the_solubility_pump_be_enhanced/links/00b7d51ae05c1f2b9d000000.pdf>. > > > > > > > [image: image.jpeg] > > > > > > Le dim. 28 juil. 2019 à 10:42, Andrew Lockley <[email protected]> > a écrit : > > Poster's note: this appears wholly impractical, to me. > > > > Dezeen: Iceberg-making submarine aims to tackle global warming by > re-freezing the Arctic. > > https://www.dezeen.com/2019/07/27/refreezing-the-arctic-geoengineering-design-climate-change/ > > > Iceberg-making submarine aims to tackle global warming by re-freezing the > Arctic > > Alyn Griffiths <https://www.dezeen.com/author/alyn-griffiths/> > > 1 day ago <https://www.dezeen.com/2019/07/27/> > > Leave a comment > <https://www-dezeen-com.cdn.ampproject.org/v/s/www.dezeen.com/2019/07/27/refreezing-the-arctic-geoengineering-design-climate-change/amp/?amp_js_v=0.1#disqus_thread> > > A team of designers led by Faris Rajak Kotahatuhaha proposes re-freezing > sea water in the Arctic <https://www.dezeen.com/tag/arctic/> to create > miniature modular icebergs using a submarine-like vessel, in a bid to > combat climate change <https://www.dezeen.com/tag/climate-change/>. > > The Indonesian designer > <https://issuu.com/fariskota/docs/faris_rajak_kotahatuhaha_-_portfoli> worked > on the prototype with collaborators Denny Lesmana Budi and Fiera Alifa for > an international competition organised by the Association of Siamese > Architects. > > The team was awarded second prize in the contest for its geoengineering > <https://www.dezeen.com/tag/geoengineering/> proposal to re-freeze the > Arctic and transform sea water into new ice fields. > > [image: Refreeze the Arctic geoengineering project by Faris Rajak > Kotahatuhaha]The designers propose a series of submarine-like vessels to > create miniature icebergs > > Kotahatuhaha's team set out to create a prototype for the > "re-iceberg-isation" of parts of the Arctic by freezing seawater into > hexagonal blocks of ice that nest together to form new ice floes. > > "The main goal of this idea is to restore the polar ecosystem, which has a > direct effect on the balance of the global climate," said the designer, > adding that in this scenario "it is better to prevent than cure". > Related story > <https://www.dezeen.com/2019/05/13/the-growing-islands-mit-self-assembly-lab/>MIT's > Self-Assembly Lab proposes new way of growing islands and coastlines > <https://www.dezeen.com/2019/05/13/the-growing-islands-mit-self-assembly-lab/> > > The concept is a proactive response to issues related to the melting of > the earth's polar ice. The designers felt that too much emphasis is > currently being placed on protecting cities from rising sea-levels rather > than tackling the problem at its source. > > In New York City, architecture firm BIG is working on a large-scale flood > defence system > <https://www.dezeen.com/2018/07/20/big-u-storm-flood-defences-east-side-coastal-resiliency-manhattan-move-forward/> > to > protect Lower Manhattan from tidal surges, while Hassell and MVRDV have > proposed a series of measures designed to protect San Francisco > <https://www.dezeen.com/2018/01/30/connect-collect-mvrdv-hassell-resilient-by-design-challenge-san-francisco-bay-area-california-usa-climate-change/> > and > the surrounding Bay Area from the encroaching ocean. > > [image: Refreeze the Arctic geoengineering project by Faris Rajak > Kotahatuhaha]Sea water would be collected in hexagonal tanks before > freezing > > The submarine-like vessel would submerge to collect sea water in a central > hexagonal tank. Turbines would then be used to blast the tank with cold air > and accelerate the freezing process. > > During this process, the vessel would return to the surface of the sea and > the tank would be covered to protect it from sunlight. A system of reverse > osmosis would be used to filter some of the salt from the water in order to > speed up the process. > > Once the water is frozen, the vessel would submerge again, leaving behind > an "ice baby" with a volume of 2,027 cubic-metres. These miniature icebergs > would then cluster together in a honeycomb pattern to form a larger ice > floe. > > [image: Refreeze the Arctic geoengineering project by Faris Rajak > Kotahatuhaha]Kotahatuhaha suggests that underwater hotels could help fund > the project > > Multiple vessels could be used to continuously repeat the process and > gradually rebuild the ice caps. > > The submarines would be large enough to accommodate additional functions > like polar research centres and underwater hotels that Kotahatuhaha > suggested could help to fund the project. > > Other radical proposals developed in response to rising sea levels include a > series of giant floating umbrellas > <https://www.dezeen.com/2013/03/13/polar-umbrella-wins-evolo-skyscraper-competition-2013/>that > could also help to replenish Arctic ice shelves, and a method for aiding > the growth of beaches and islands > <https://www.dezeen.com/2019/05/13/the-growing-islands-mit-self-assembly-lab/> > in > vulnerable coastal regions. > > Read more: > > · Design <https://www.dezeen.com/tag/design-tag/> > > · Movies <https://www.dezeen.com/tag/movies/> > > · Technology <https://www.dezeen.com/tag/technology-tag/> > > · Design movies <https://www.dezeen.com/tag/design-movies/> > > · Climate change <https://www.dezeen.com/tag/climate-change/> > > · Geoengineering <https://www.dezeen.com/tag/geoengineering/> > > · Arctic <https://www.dezeen.com/tag/arctic/> > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/CAJ3C-06Ldv1cRa6kgmRmzoAda46NWfyJAsfx6NFh%2BM%3DqdT1MbA%40mail.gmail.com > <https://groups.google.com/d/msgid/geoengineering/CAJ3C-06Ldv1cRa6kgmRmzoAda46NWfyJAsfx6NFh%2BM%3DqdT1MbA%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > -- > 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 view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/CAHodn9-1_kOkEXB9zn3nnP2XuVqOQkyB9s9qeofCKnyb94kWGw%40mail.gmail.com > <https://groups.google.com/d/msgid/geoengineering/CAHodn9-1_kOkEXB9zn3nnP2XuVqOQkyB9s9qeofCKnyb94kWGw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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