Re: [geo] Ocean waves influence sea ice extent
Andrew Making a round hole in a plate increases the adjacent stress by a factor of three so this is a really great way to assist breakup. The single frequency observation is because that part of the wave spectrum has a phase velocity which coincides with the velocity of the flexure wave in the ice plate. This will happen less if ice gets broken and floes get stacked on one another so that you get local changes in flexure stiffness. Stephen Emeritus Professor of Engineering Design. School of Engineering. University of Edinburgh. Mayfield Road. Edinburgh EH9 3JL. Scotland. s.sal...@ed.ac.uk Tel +44 (0)131 650 5704 Cell 07795 203 195 WWW.see.ed.ac.uk/~shs U-tube Jamie Taylor Power for Change On 29/05/2014 19:53, Andrew Lockley wrote: Any ideas on this? Some possibilities: Drill holes in ice to allow water to slosh through. Binding ice together with straw, etc. Inject air under the ice Ocean waves influence sea ice extent http://www.bbc.co.uk/news/science-environment-27591369 Ocean waves influence sea ice extent 29 May 2014 11:51 By Jonathan Amos Science correspondent, BBC News The team placed sensors on the floes to track the disturbance caused by ocean waves Large ocean waves can travel through sea ice for hundreds of kilometres before their oscillations are finally dampened, scientists have shown. The up and down motion can fracture the ice, potentially aiding its break-up and melting, the researchers told Nature magazine. They say storm swells may have a much bigger influence on the extent of polar sea ice than previously recognised. The New Zealand-led team ran its experiments off Antarctica. They placed sensors at various distances from the edge of the pack ice, and then recorded what happened when bad weather whipped up the ocean surface. For smaller waves, less than 3m in height, the bobbing induced in the floes quickly decayed. But for waves over 3m, the disturbance sent propagating through the pack ice was sustained for up to 350km. At the ice edge, it's quite noisy, explained study lead author Alison Kohout, from New Zealand's National Institute of Water and Atmospheric Research in Christchurch. You have lots of waves coming from all directions with a full spectrum of frequencies. But as the waves move into the ice, this all gets cleaned up to produce one beautiful, smooth wave of constant frequency, she told BBC News. The ice floes bend with the waves, and over time you can imagine that this creates fatigue and eventually the ice will fracture. Interestingly, the fractures tend to be perpendicular to the direction of the waves, and to be of even widths. The fractures tend to be perpendicular to the direction of the waves, and to be of even widths Computer modellers have been trying to simulate the recent trends in polar sea ice - without a great deal of success. They have failed to capture both the very rapid decline in summer ice cover in the Arctic and the small, but nonetheless significant, growth in winter ice in the Antarctic. Dr Kohout and colleagues say their experiments offer some clues - certainly in the south. When they compared observed Antarctic marine-ice edge positions from 1997 to 2009 with likely wave heights generated by the weather during that period, they found a strong link. For example, where storminess was increased, in regions like the Amundsen-Bellingshausen Sea, ice extent was curtailed. In contrast, where wave heights were smaller, such as in the Western Ross Sea, marine ice was seen to expand. One very noticeable aspect of the recent growth in Antarctic winter sea ice has been its high regional variability. The team says that if models take more account of wave heights then they may better capture some of this behaviour. The recent growth in Antarctic sea ice has been a highly regional phenomenon The group did try to look for a similar relationship in storminess and ice extent in the Arctic but found there to be insufficient data to draw any firm conclusions. The geography at the poles is quite different. The Arctic is in large part an ocean enclosed by land, whereas the Antarctic is a land mass totally surrounded by ocean. Many of the ice behaviours and responses are different as a result. I think what's interesting for us in the Arctic is that the 'fetch' is increasing - the distance from the shores to the ice edge is increasing, commented Prof Julienne Stroeve from University College London and the US National Snow and Ice Data Center. That would allow the wind to work more on the ocean to produce larger waves that can then propagate further into the ice pack. [Another recent paper has already suggested] that wave heights are going to change with increasing distance from the ice edge to the land, and that could have more of an impact on ice break-up. jonathan.amos-inter...@bbc.co.uk mailto:jonathan.amos-inter...@bbc.co.uk and follow me on Twitter: @BBCAmos
Re: [geo] Ocean waves influence sea ice extent
You would likely use slits perpendicular to the direction of travel of the wave, not round holes. These would quickly attenuate wave energy, and may also help build ice by flooding the surface. A On 30 May 2014 09:46, Stephen Salter s.sal...@ed.ac.uk wrote: Andrew Making a round hole in a plate increases the adjacent stress by a factor of three so this is a really great way to assist breakup. The single frequency observation is because that part of the wave spectrum has a phase velocity which coincides with the velocity of the flexure wave in the ice plate. This will happen less if ice gets broken and floes get stacked on one another so that you get local changes in flexure stiffness. Stephen Emeritus Professor of Engineering Design. School of Engineering. University of Edinburgh. Mayfield Road. Edinburgh EH9 3JL. Scotland. s.sal...@ed.ac.uk Tel +44 (0)131 650 5704 Cell 07795 203 195 WWW.see.ed.ac.uk/~shs U-tube Jamie Taylor Power for Change On 29/05/2014 19:53, Andrew Lockley wrote: Any ideas on this? Some possibilities: Drill holes in ice to allow water to slosh through. Binding ice together with straw, etc. Inject air under the ice Ocean waves influence sea ice extent http://www.bbc.co.uk/news/science-environment-27591369 Ocean waves influence sea ice extent 29 May 2014 11:51 By Jonathan Amos Science correspondent, BBC News The team placed sensors on the floes to track the disturbance caused by ocean waves Large ocean waves can travel through sea ice for hundreds of kilometres before their oscillations are finally dampened, scientists have shown. The up and down motion can fracture the ice, potentially aiding its break-up and melting, the researchers told Nature magazine. They say storm swells may have a much bigger influence on the extent of polar sea ice than previously recognised. The New Zealand-led team ran its experiments off Antarctica. They placed sensors at various distances from the edge of the pack ice, and then recorded what happened when bad weather whipped up the ocean surface. For smaller waves, less than 3m in height, the bobbing induced in the floes quickly decayed. But for waves over 3m, the disturbance sent propagating through the pack ice was sustained for up to 350km. At the ice edge, it's quite noisy, explained study lead author Alison Kohout, from New Zealand's National Institute of Water and Atmospheric Research in Christchurch. You have lots of waves coming from all directions with a full spectrum of frequencies. But as the waves move into the ice, this all gets cleaned up to produce one beautiful, smooth wave of constant frequency, she told BBC News. The ice floes bend with the waves, and over time you can imagine that this creates fatigue and eventually the ice will fracture. Interestingly, the fractures tend to be perpendicular to the direction of the waves, and to be of even widths. The fractures tend to be perpendicular to the direction of the waves, and to be of even widths Computer modellers have been trying to simulate the recent trends in polar sea ice - without a great deal of success. They have failed to capture both the very rapid decline in summer ice cover in the Arctic and the small, but nonetheless significant, growth in winter ice in the Antarctic. Dr Kohout and colleagues say their experiments offer some clues - certainly in the south. When they compared observed Antarctic marine-ice edge positions from 1997 to 2009 with likely wave heights generated by the weather during that period, they found a strong link. For example, where storminess was increased, in regions like the Amundsen-Bellingshausen Sea, ice extent was curtailed. In contrast, where wave heights were smaller, such as in the Western Ross Sea, marine ice was seen to expand. One very noticeable aspect of the recent growth in Antarctic winter sea ice has been its high regional variability. The team says that if models take more account of wave heights then they may better capture some of this behaviour. The recent growth in Antarctic sea ice has been a highly regional phenomenon The group did try to look for a similar relationship in storminess and ice extent in the Arctic but found there to be insufficient data to draw any firm conclusions. The geography at the poles is quite different. The Arctic is in large part an ocean enclosed by land, whereas the Antarctic is a land mass totally surrounded by ocean. Many of the ice behaviours and responses are different as a result. I think what's interesting for us in the Arctic is that the 'fetch' is increasing - the distance from the shores to the ice edge is increasing, commented Prof Julienne Stroeve from University College London and the US National Snow and Ice Data Center. That would allow the wind to work more on the ocean to produce larger waves that can then propagate further into the ice pack. [Another recent paper has already
Re: [geo] Ocean waves influence sea ice extent
Andrew The stress concentration factor of a slit is even higher than for a round hole. Unless you are in very shallow water there is quite a wide spread of wave directions. Stephen Emeritus Professor of Engineering Design. School of Engineering. University of Edinburgh. Mayfield Road. Edinburgh EH9 3JL. Scotland. s.sal...@ed.ac.uk Tel +44 (0)131 650 5704 Cell 07795 203 195 WWW.see.ed.ac.uk/~shs U-tube Jamie Taylor Power for Change On 30/05/2014 09:56, Andrew Lockley wrote: You would likely use slits perpendicular to the direction of travel of the wave, not round holes. These would quickly attenuate wave energy, and may also help build ice by flooding the surface. A On 30 May 2014 09:46, Stephen Salter s.sal...@ed.ac.uk mailto:s.sal...@ed.ac.uk wrote: Andrew Making a round hole in a plate increases the adjacent stress by a factor of three so this is a really great way to assist breakup. The single frequency observation is because that part of the wave spectrum has a phase velocity which coincides with the velocity of the flexure wave in the ice plate. This will happen less if ice gets broken and floes get stacked on one another so that you get local changes in flexure stiffness. Stephen Emeritus Professor of Engineering Design. School of Engineering. University of Edinburgh. Mayfield Road. Edinburgh EH9 3JL. Scotland. s.sal...@ed.ac.uk mailto:s.sal...@ed.ac.uk Tel +44 (0)131 650 5704 tel:%2B44%20%280%29131%20650%205704 Cell 07795 203 195 WWW.see.ed.ac.uk/~shs http://WWW.see.ed.ac.uk/%7Eshs U-tube Jamie Taylor Power for Change On 29/05/2014 19:53, Andrew Lockley wrote: Any ideas on this? Some possibilities: Drill holes in ice to allow water to slosh through. Binding ice together with straw, etc. Inject air under the ice Ocean waves influence sea ice extent http://www.bbc.co.uk/news/science-environment-27591369 Ocean waves influence sea ice extent 29 May 2014 11:51 By Jonathan Amos Science correspondent, BBC News The team placed sensors on the floes to track the disturbance caused by ocean waves Large ocean waves can travel through sea ice for hundreds of kilometres before their oscillations are finally dampened, scientists have shown. The up and down motion can fracture the ice, potentially aiding its break-up and melting, the researchers told Nature magazine. They say storm swells may have a much bigger influence on the extent of polar sea ice than previously recognised. The New Zealand-led team ran its experiments off Antarctica. They placed sensors at various distances from the edge of the pack ice, and then recorded what happened when bad weather whipped up the ocean surface. For smaller waves, less than 3m in height, the bobbing induced in the floes quickly decayed. But for waves over 3m, the disturbance sent propagating through the pack ice was sustained for up to 350km. At the ice edge, it's quite noisy, explained study lead author Alison Kohout, from New Zealand's National Institute of Water and Atmospheric Research in Christchurch. You have lots of waves coming from all directions with a full spectrum of frequencies. But as the waves move into the ice, this all gets cleaned up to produce one beautiful, smooth wave of constant frequency, she told BBC News. The ice floes bend with the waves, and over time you can imagine that this creates fatigue and eventually the ice will fracture. Interestingly, the fractures tend to be perpendicular to the direction of the waves, and to be of even widths. The fractures tend to be perpendicular to the direction of the waves, and to be of even widths Computer modellers have been trying to simulate the recent trends in polar sea ice - without a great deal of success. They have failed to capture both the very rapid decline in summer ice cover in the Arctic and the small, but nonetheless significant, growth in winter ice in the Antarctic. Dr Kohout and colleagues say their experiments offer some clues - certainly in the south. When they compared observed Antarctic marine-ice edge positions from 1997 to 2009 with likely wave heights generated by the weather during that period, they found a strong link. For example, where storminess was increased, in regions like the Amundsen-Bellingshausen Sea, ice extent was curtailed. In contrast, where wave heights were smaller, such as in the Western Ross Sea, marine ice was seen to expand. One very noticeable aspect of the recent growth in Antarctic winter sea ice has been its high regional variability. The team says that if models take more account of wave heights then they may better capture some of this behaviour. The recent growth in Antarctic sea ice has been a highly regional
[geo] Re: Ocean waves influence sea ice extent
Andrew/Stephen Punching shear is phenomena structural engineers know about. A flat plate (usually concrete) with a column punching through will propagate cracks in all directions which they try to avoid. In this case perhaps air vehicles like helicopters can be fitted with mechanical punchers without having to land or man anyone on ice. Parminder Singh Malaysia On Friday, May 30, 2014 2:53:12 AM UTC+8, andrewjlockley wrote: Any ideas on this? Some possibilities: Drill holes in ice to allow water to slosh through. Binding ice together with straw, etc. Inject air under the ice Ocean waves influence sea ice extent http://www.bbc.co.uk/news/science-environment-27591369 Ocean waves influence sea ice extent 29 May 2014 11:51 By Jonathan Amos Science correspondent, BBC News The team placed sensors on the floes to track the disturbance caused by ocean waves Large ocean waves can travel through sea ice for hundreds of kilometres before their oscillations are finally dampened, scientists have shown. The up and down motion can fracture the ice, potentially aiding its break-up and melting, the researchers told Nature magazine. They say storm swells may have a much bigger influence on the extent of polar sea ice than previously recognised. The New Zealand-led team ran its experiments off Antarctica. They placed sensors at various distances from the edge of the pack ice, and then recorded what happened when bad weather whipped up the ocean surface. For smaller waves, less than 3m in height, the bobbing induced in the floes quickly decayed. But for waves over 3m, the disturbance sent propagating through the pack ice was sustained for up to 350km. At the ice edge, it's quite noisy, explained study lead author Alison Kohout, from New Zealand's National Institute of Water and Atmospheric Research in Christchurch. You have lots of waves coming from all directions with a full spectrum of frequencies. But as the waves move into the ice, this all gets cleaned up to produce one beautiful, smooth wave of constant frequency, she told BBC News. The ice floes bend with the waves, and over time you can imagine that this creates fatigue and eventually the ice will fracture. Interestingly, the fractures tend to be perpendicular to the direction of the waves, and to be of even widths. The fractures tend to be perpendicular to the direction of the waves, and to be of even widths Computer modellers have been trying to simulate the recent trends in polar sea ice - without a great deal of success. They have failed to capture both the very rapid decline in summer ice cover in the Arctic and the small, but nonetheless significant, growth in winter ice in the Antarctic. Dr Kohout and colleagues say their experiments offer some clues - certainly in the south. When they compared observed Antarctic marine-ice edge positions from 1997 to 2009 with likely wave heights generated by the weather during that period, they found a strong link. For example, where storminess was increased, in regions like the Amundsen-Bellingshausen Sea, ice extent was curtailed. In contrast, where wave heights were smaller, such as in the Western Ross Sea, marine ice was seen to expand. One very noticeable aspect of the recent growth in Antarctic winter sea ice has been its high regional variability. The team says that if models take more account of wave heights then they may better capture some of this behaviour. The recent growth in Antarctic sea ice has been a highly regional phenomenon The group did try to look for a similar relationship in storminess and ice extent in the Arctic but found there to be insufficient data to draw any firm conclusions. The geography at the poles is quite different. The Arctic is in large part an ocean enclosed by land, whereas the Antarctic is a land mass totally surrounded by ocean. Many of the ice behaviours and responses are different as a result. I think what's interesting for us in the Arctic is that the 'fetch' is increasing - the distance from the shores to the ice edge is increasing, commented Prof Julienne Stroeve from University College London and the US National Snow and Ice Data Center. That would allow the wind to work more on the ocean to produce larger waves that can then propagate further into the ice pack. [Another recent paper has already suggested] that wave heights are going to change with increasing distance from the ice edge to the land, and that could have more of an impact on ice break-up. jonathan.am...@bbc.co.uk javascript: and follow me on Twitter: @BBCAmos BBC © 2014 -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to
[geo] Mitigate the sea-level rise
I posted the following a few years ago . I'm putting it out again to see if there's further reaction The following is so simple and obvious, perhaps it's not so obvious ! It's low-tech and uses a large hammer to help crack a very large nut. It will not solve the problem of sea-level rise, but might mitigate it somewhat. Major negative side affects are envisaged - more about that later. The idea is to use brute force to bury the problem in the sand ! Where ? - in the deserts ! -- some parts of Earth's surface (which cannot be named for diplomatic reasons) are not as pretty as other parts (e.g. the tropical rainforests), and might magnanimously offer themselves (with the help of financial incentives) for the greater good. If sufficient numbers of pumps of sufficient bore/capacity pump sea-water for sufficiently long periods onto/into these wastelands, then at least a temporary halt in the millimeter by millimeter rise might be affected. Yes there would be major ecological consequences, not least the changing of weather patterns on which many populations both human and non-human rely. But I believe these would be temporary one-off changes and a new ecological balance would eventually ensue. The adage No pain, no gain may apply. * The existing ecological beauty of the affected areas would be permanently altered if not destroyed. * There would be large-scale evaporation, causing a large percentage of the water to eventally return (as freshwater) to where it's not wanted ! However experiments to determine what fraction would be permanently soaked up in different landscapes might give widely different results. Obviously those areas that indicate a high absorption coefficient or soakability factor (sand dunes ?) would be best suited to large-scale water transfer. * Care would need to be taken to ensure that no one specific region received more sea-water than the underlying mantle can safely support - the sheer weight of the water added could possibly produce a fissure in Earth's crust. On the positive side, if as a consequence of the exercise, large areas were left with a surface of salt which had a higher reflectivity than what existed before (albedo effect), this would act as a mirror and cause more radiation to be reflected back to space. Ingenious or idiotic ??? -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
RE: [geo] Ocean waves influence sea ice extent
My thought: thicken the ice by pumping water from under the ice to the top during the winter, using barge mounted pumps powered by wind generated electricity. Stronger, more mass, hence slower to melt. Peter Peter Flynn, P. Eng., Ph. D. Emeritus Professor and Poole Chair in Management for Engineers Department of Mechanical Engineering University of Alberta peter.fl...@ualberta.ca cell: 928 451 4455 *From:* geoengineering@googlegroups.com [mailto: geoengineering@googlegroups.com] *On Behalf Of *Andrew Lockley *Sent:* May-29-14 12:53 PM *To:* geoengineering *Subject:* [geo] Ocean waves influence sea ice extent Any ideas on this? Some possibilities: Drill holes in ice to allow water to slosh through. Binding ice together with straw, etc. Inject air under the ice Ocean waves influence sea ice extent http://www.bbc.co.uk/news/science-environment-27591369 Ocean waves influence sea ice extent 29 May 2014 11:51 By Jonathan Amos Science correspondent, BBC News The team placed sensors on the floes to track the disturbance caused by ocean waves Large ocean waves can travel through sea ice for hundreds of kilometres before their oscillations are finally dampened, scientists have shown. The up and down motion can fracture the ice, potentially aiding its break-up and melting, the researchers told Nature magazine. They say storm swells may have a much bigger influence on the extent of polar sea ice than previously recognised. The New Zealand-led team ran its experiments off Antarctica. They placed sensors at various distances from the edge of the pack ice, and then recorded what happened when bad weather whipped up the ocean surface. For smaller waves, less than 3m in height, the bobbing induced in the floes quickly decayed. But for waves over 3m, the disturbance sent propagating through the pack ice was sustained for up to 350km. At the ice edge, it's quite noisy, explained study lead author Alison Kohout, from New Zealand's National Institute of Water and Atmospheric Research in Christchurch. You have lots of waves coming from all directions with a full spectrum of frequencies. But as the waves move into the ice, this all gets cleaned up to produce one beautiful, smooth wave of constant frequency, she told BBC News. The ice floes bend with the waves, and over time you can imagine that this creates fatigue and eventually the ice will fracture. Interestingly, the fractures tend to be perpendicular to the direction of the waves, and to be of even widths. The fractures tend to be perpendicular to the direction of the waves, and to be of even widths Computer modellers have been trying to simulate the recent trends in polar sea ice - without a great deal of success. They have failed to capture both the very rapid decline in summer ice cover in the Arctic and the small, but nonetheless significant, growth in winter ice in the Antarctic. Dr Kohout and colleagues say their experiments offer some clues - certainly in the south. When they compared observed Antarctic marine-ice edge positions from 1997 to 2009 with likely wave heights generated by the weather during that period, they found a strong link. For example, where storminess was increased, in regions like the Amundsen-Bellingshausen Sea, ice extent was curtailed. In contrast, where wave heights were smaller, such as in the Western Ross Sea, marine ice was seen to expand. One very noticeable aspect of the recent growth in Antarctic winter sea ice has been its high regional variability. The team says that if models take more account of wave heights then they may better capture some of this behaviour. The recent growth in Antarctic sea ice has been a highly regional phenomenon The group did try to look for a similar relationship in storminess and ice extent in the Arctic but found there to be insufficient data to draw any firm conclusions. The geography at the poles is quite different. The Arctic is in large part an ocean enclosed by land, whereas the Antarctic is a land mass totally surrounded by ocean. Many of the ice behaviours and responses are different as a result. I think what's interesting for us in the Arctic is that the 'fetch' is increasing - the distance from the shores to the ice edge is increasing, commented Prof Julienne Stroeve from University College London and the US National Snow and Ice Data Center. That would allow the wind to work more on the ocean to produce larger waves that can then propagate further into the ice pack. [Another recent paper has already suggested] that wave heights are going to change with increasing distance from the ice edge to the land, and that could have more of an impact on ice break-up. jonathan.amos-inter...@bbc.co.uk and follow me on Twitter: @BBCAmos BBC © 2014 -- 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
Re: [geo] Mitigate the sea-level rise
The world's largest pump does 150,000 gallons a second, and costs around $500 Million, and is only pumping a few feet. http://www.popsci.com/scitech/article/2009-08/saving-new-orleans-worlds-largest-water-pump To offset 1 cm of sea level rise, this pump would have to run for 200 years. http://www.wolframalpha.com/input/?i=%28360+million+km2+*+1+cm%29+%2F+%2815+gallons%29+seconds+in+years Or you could have 200 pumps do 1cm per year, at a baseline cost of $100 Billion. But if you factor in distance and evaporation you'd probably need a lot more. Combined with the likely saturation of the area with only a small fraction of the 1cm worth of water, the destruction of the local ecosystem, and the need for continued pumping - I'd say this idea is a non-starter. Mick On Thu, May 29, 2014 at 7:54 AM, Celsus celso...@gmail.com wrote: I posted the following a few years ago . I'm putting it out again to see if there's further reaction The following is so simple and obvious, perhaps it's not so obvious ! It's low-tech and uses a large hammer to help crack a very large nut. It will not solve the problem of sea-level rise, but might mitigate it somewhat. Major negative side affects are envisaged - more about that later. The idea is to use brute force to bury the problem in the sand ! Where ? - in the deserts ! -- some parts of Earth's surface (which cannot be named for diplomatic reasons) are not as pretty as other parts (e.g. the tropical rainforests), and might magnanimously offer themselves (with the help of financial incentives) for the greater good. If sufficient numbers of pumps of sufficient bore/capacity pump sea-water for sufficiently long periods onto/into these wastelands, then at least a temporary halt in the millimeter by millimeter rise might be affected. Yes there would be major ecological consequences, not least the changing of weather patterns on which many populations both human and non-human rely. But I believe these would be temporary one-off changes and a new ecological balance would eventually ensue. The adage No pain, no gain may apply. * The existing ecological beauty of the affected areas would be permanently altered if not destroyed. * There would be large-scale evaporation, causing a large percentage of the water to eventally return (as freshwater) to where it's not wanted ! However experiments to determine what fraction would be permanently soaked up in different landscapes might give widely different results. Obviously those areas that indicate a high absorption coefficient or soakability factor (sand dunes ?) would be best suited to large-scale water transfer. * Care would need to be taken to ensure that no one specific region received more sea-water than the underlying mantle can safely support - the sheer weight of the water added could possibly produce a fissure in Earth's crust. On the positive side, if as a consequence of the exercise, large areas were left with a surface of salt which had a higher reflectivity than what existed before (albedo effect), this would act as a mirror and cause more radiation to be reflected back to space. Ingenious or idiotic ??? -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
Re: [geo] Mitigate the sea-level rise
Mick Water runs down hill. If you look at the rock porosity and the depths of the water table below the Sahara you can see that we could store a world-metre of sea water down there. So why does it not flow down of its own accord? Answer because ooze on the sea bed in the oceans surrounding the Sahara has clogged the entrances to all the subterranean passages. All we have to do is some ooze-scraping to clear the blockage.Water below the Sahara is already extremely saline. We would have to provide solar-powered desalination plant for every man, woman, child, camel and goat but that would be much cheaper than building a flood wall round Manhattan let alone all the other coastal cities. I have been working on designs of wave-powered scrapers so we can do it without releasing any carbon from fossil fuel. If we can wash the salt it might be quite valuable. Stephen Emeritus Professor of Engineering Design. School of Engineering. University of Edinburgh. Mayfield Road. Edinburgh EH9 3JL. Scotland. s.sal...@ed.ac.uk Tel +44 (0)131 650 5704 Cell 07795 203 195 WWW.see.ed.ac.uk/~shs U-tube Jamie Taylor Power for Change On 30/05/2014 17:16, Mick West wrote: The world's largest pump does 150,000 gallons a second, and costs around $500 Million, and is only pumping a few feet. http://www.popsci.com/scitech/article/2009-08/saving-new-orleans-worlds-largest-water-pump To offset 1 cm of sea level rise, this pump would have to run for 200 years. http://www.wolframalpha.com/input/?i=%28360+million+km2+*+1+cm%29+%2F+%2815+gallons%29+seconds+in+years Or you could have 200 pumps do 1cm per year, at a baseline cost of $100 Billion. But if you factor in distance and evaporation you'd probably need a lot more. Combined with the likely saturation of the area with only a small fraction of the 1cm worth of water, the destruction of the local ecosystem, and the need for continued pumping - I'd say this idea is a non-starter. Mick On Thu, May 29, 2014 at 7:54 AM, Celsus celso...@gmail.com mailto:celso...@gmail.com wrote: I posted the following a few years ago . I'm putting it out again to see if there's further reaction The following is so simple and obvious, perhaps it's not so obvious ! It's low-tech and uses a large hammer to help crack a very large nut. It will not solve the problem of sea-level rise, but might mitigate it somewhat. Major negative side affects are envisaged - more about that later. The idea is to use brute force to bury the problem in the sand ! Where ? - in the deserts ! -- some parts of Earth's surface (which cannot be named for diplomatic reasons) are not as pretty as other parts (e.g. the tropical rainforests), and might magnanimously offer themselves (with the help of financial incentives) for the greater good. If sufficient numbers of pumps of sufficient bore/capacity pump sea-water for sufficiently long periods onto/into these wastelands, then at least a temporary halt in the millimeter by millimeter rise might be affected. Yes there would be major ecological consequences, not least the changing of weather patterns on which many populations both human and non-human rely. But I believe these would be temporary one-off changes and a new ecological balance would eventually ensue. The adage No pain, no gain may apply. * The existing ecological beauty of the affected areas would be permanently altered if not destroyed. * There would be large-scale evaporation, causing a large percentage of the water to eventally return (as freshwater) to where it's not wanted ! However experiments to determine what fraction would be permanently soaked up in different landscapes might give widely different results. Obviously those areas that indicate a high absorption coefficient or soakability factor (sand dunes ?) would be best suited to large-scale water transfer. * Care would need to be taken to ensure that no one specific region received more sea-water than the underlying mantle can safely support - the sheer weight of the water added could possibly produce a fissure in Earth's crust. On the positive side, if as a consequence of the exercise, large areas were left with a surface of salt which had a higher reflectivity than what existed before (albedo effect), this would act as a mirror and cause more radiation to be reflected back to space. Ingenious or idiotic ??? -- 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 geoengineering+unsubscr...@googlegroups.com mailto:geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com mailto:geoengineering@googlegroups.com. Visit this
Re: [geo] Ocean waves influence sea ice extent
Why not try to increase the duration and intensity of polar storms? We've already got a good start on that with the massive ongoing global effort to increase the intensity and frequency of extreme weather events. Seriously, it baffles me that sometimes it seems that the response here to every new piece of climate science is to figure out if there's a way we can use it in geoengineering. On Thu, May 29, 2014 at 2:53 PM, Andrew Lockley andrew.lock...@gmail.com wrote: Any ideas on this? Some possibilities: Drill holes in ice to allow water to slosh through. Binding ice together with straw, etc. Inject air under the ice Ocean waves influence sea ice extent http://www.bbc.co.uk/news/science-environment-27591369 Ocean waves influence sea ice extent 29 May 2014 11:51 By Jonathan Amos Science correspondent, BBC News The team placed sensors on the floes to track the disturbance caused by ocean waves Large ocean waves can travel through sea ice for hundreds of kilometres before their oscillations are finally dampened, scientists have shown. The up and down motion can fracture the ice, potentially aiding its break-up and melting, the researchers told Nature magazine. They say storm swells may have a much bigger influence on the extent of polar sea ice than previously recognised. The New Zealand-led team ran its experiments off Antarctica. They placed sensors at various distances from the edge of the pack ice, and then recorded what happened when bad weather whipped up the ocean surface. For smaller waves, less than 3m in height, the bobbing induced in the floes quickly decayed. But for waves over 3m, the disturbance sent propagating through the pack ice was sustained for up to 350km. At the ice edge, it's quite noisy, explained study lead author Alison Kohout, from New Zealand's National Institute of Water and Atmospheric Research in Christchurch. You have lots of waves coming from all directions with a full spectrum of frequencies. But as the waves move into the ice, this all gets cleaned up to produce one beautiful, smooth wave of constant frequency, she told BBC News. The ice floes bend with the waves, and over time you can imagine that this creates fatigue and eventually the ice will fracture. Interestingly, the fractures tend to be perpendicular to the direction of the waves, and to be of even widths. The fractures tend to be perpendicular to the direction of the waves, and to be of even widths Computer modellers have been trying to simulate the recent trends in polar sea ice - without a great deal of success. They have failed to capture both the very rapid decline in summer ice cover in the Arctic and the small, but nonetheless significant, growth in winter ice in the Antarctic. Dr Kohout and colleagues say their experiments offer some clues - certainly in the south. When they compared observed Antarctic marine-ice edge positions from 1997 to 2009 with likely wave heights generated by the weather during that period, they found a strong link. For example, where storminess was increased, in regions like the Amundsen-Bellingshausen Sea, ice extent was curtailed. In contrast, where wave heights were smaller, such as in the Western Ross Sea, marine ice was seen to expand. One very noticeable aspect of the recent growth in Antarctic winter sea ice has been its high regional variability. The team says that if models take more account of wave heights then they may better capture some of this behaviour. The recent growth in Antarctic sea ice has been a highly regional phenomenon The group did try to look for a similar relationship in storminess and ice extent in the Arctic but found there to be insufficient data to draw any firm conclusions. The geography at the poles is quite different. The Arctic is in large part an ocean enclosed by land, whereas the Antarctic is a land mass totally surrounded by ocean. Many of the ice behaviours and responses are different as a result. I think what's interesting for us in the Arctic is that the 'fetch' is increasing - the distance from the shores to the ice edge is increasing, commented Prof Julienne Stroeve from University College London and the US National Snow and Ice Data Center. That would allow the wind to work more on the ocean to produce larger waves that can then propagate further into the ice pack. [Another recent paper has already suggested] that wave heights are going to change with increasing distance from the ice edge to the land, and that could have more of an impact on ice break-up. jonathan.amos-inter...@bbc.co.uk and follow me on Twitter: @BBCAmos BBC © 2014 -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com.
[geo] Re: TEDx talk on GE
Dear Greg (and list) -- I appreciate your taking the time to watch my TEDx talk. Please note that I was directed by the organizers to give a talk for a general audience. What sounds like the usual handwringing to you is, I hazard, important information and context for people who are not yet paying attention to the climate geoengineering conversation. My general intent in the talk was to highlight why geoengineering is such a complex and thorny notion. There are no geoengineering solutions to climate change. There are good arguments, though, for the investigation and consideration of certain geoengineering technologies as part of a concerted climate change response. I highlighted many of those arguments in the talk. Most notably, I am drawn to the geoengineering conversation because, like you, I'm deeply concerned about the inability, to date, of our political and social systems to grapple with climate change in any kind of meaningful way. At the same time, I, like many others, harbor deep reservations about the ways in which talk of geoengineering may distract from mitigation efforts; about the abilities of entrenched actors, along with powerful cultural and political forces, to drive geoengineering development in harmful directions; about the narrow array of perspectives apparent in much geoengineering talk; and many other aspects of the geoengineering project. These are messy issues that broach few easy answers. I hope you'll see that the talk was an honest attempt to unpack some of that complexity for newcomers. The Washington Geoengineering Consortium http://dcgeoconsortium.org/, a study and public outreach group that I set up with Wil Burns and Michael Thompson, is committed to advancing the geoengineering conversation in productive ways, in part by opening the conversation to a wider array of voices. We welcome any constructive thinking on how best to achieve that goal. Best, Simon On Thursday, May 29, 2014 12:04:30 PM UTC-4, Greg Rau wrote: The usual handwringing. Toward the end the plea of some NGO's, No False Solutions, is highlighted. No argument there, to which I would add how about some effective solutions, and since conventional one's don't seem to be working, how about investigating alternatives, just in case? Greg https://www.youtube.com/watch?v=f2UoGcqIT3Qfeature=em-uploademail *Published on May 24, 2014* Simon Nicholson is a member of the Global Environmental Politics faculty in the School of International Service at American University. He is also one of the co-founders of the Washington Geoengineering Consortium, an academic group building a more robust conversation around the social, legal, and political implications of geoengineering technologies. Simon's research, teaching, and public engagement focus on global food politics and the politics of emerging technologies, including geoengineering. He has a long record of effective advocacy on global hunger and climate change research and action. Climate Geoengineering: Coming Soon to a Planet Near You Filmed by Ford Fischer and Justin Parker Edited by Ford Fischer Space-based mirrors. Injecting sulfate particles into the stratosphere. Seeding the oceans with iron. These and a wide range of other climate geoengineering schemes are gaining greater credibility and visibility as options for tackling climate change. What, though, is to be made of such efforts? Is climate geoengineering a new form of hucksterism? A dangerous and distracting folly? Or some meaningful part of the toolkit needed to generate a sustainable future? -- 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 geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
RE: [geo] Mitigate the sea-level rise
Relatedly, there is an interesting scheme (being tested/built in the Middle East somewhere) that I think goes like this. A natural or artificial marine bay is covered with a high arching cover such that during the day the enclosed space is solar heated and seawater evaporates. During the night the cover naturally cools, freshwater condenses on the inside, trickles down the inside of the cover and is collected to water fields, etc. If water is collected high enough it could be sent inland via gravity/pipe (+- hydroelectric generation?). OK, probably won't stem sea level rise, but might do some good in the meantime, pending GE governance approval. Greg From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] on behalf of Mick West [m...@mickwest.com] Sent: Friday, May 30, 2014 9:16 AM To: celso...@gmail.com Cc: geoengineering Subject: Re: [geo] Mitigate the sea-level rise The world's largest pump does 150,000 gallons a second, and costs around $500 Million, and is only pumping a few feet. http://www.popsci.com/scitech/article/2009-08/saving-new-orleans-worlds-largest-water-pump To offset 1 cm of sea level rise, this pump would have to run for 200 years. http://www.wolframalpha.com/input/?i=%28360+million+km2+*+1+cm%29+%2F+%2815+gallons%29+seconds+in+years Or you could have 200 pumps do 1cm per year, at a baseline cost of $100 Billion. But if you factor in distance and evaporation you'd probably need a lot more. Combined with the likely saturation of the area with only a small fraction of the 1cm worth of water, the destruction of the local ecosystem, and the need for continued pumping - I'd say this idea is a non-starter. Mick On Thu, May 29, 2014 at 7:54 AM, Celsus celso...@gmail.commailto:celso...@gmail.com wrote: I posted the following a few years ago . I'm putting it out again to see if there's further reaction The following is so simple and obvious, perhaps it's not so obvious ! It's low-tech and uses a large hammer to help crack a very large nut. It will not solve the problem of sea-level rise, but might mitigate it somewhat. Major negative side affects are envisaged - more about that later. The idea is to use brute force to bury the problem in the sand ! Where ? - in the deserts ! -- some parts of Earth's surface (which cannot be named for diplomatic reasons) are not as pretty as other parts (e.g. the tropical rainforests), and might magnanimously offer themselves (with the help of financial incentives) for the greater good. If sufficient numbers of pumps of sufficient bore/capacity pump sea-water for sufficiently long periods onto/into these wastelands, then at least a temporary halt in the millimeter by millimeter rise might be affected. Yes there would be major ecological consequences, not least the changing of weather patterns on which many populations both human and non-human rely. But I believe these would be temporary one-off changes and a new ecological balance would eventually ensue. The adage No pain, no gain may apply. * The existing ecological beauty of the affected areas would be permanently altered if not destroyed. * There would be large-scale evaporation, causing a large percentage of the water to eventally return (as freshwater) to where it's not wanted ! However experiments to determine what fraction would be permanently soaked up in different landscapes might give widely different results. Obviously those areas that indicate a high absorption coefficient or soakability factor (sand dunes ?) would be best suited to large-scale water transfer. * Care would need to be taken to ensure that no one specific region received more sea-water than the underlying mantle can safely support - the sheer weight of the water added could possibly produce a fissure in Earth's crust. On the positive side, if as a consequence of the exercise, large areas were left with a surface of salt which had a higher reflectivity than what existed before (albedo effect), this would act as a mirror and cause more radiation to be reflected back to space. Ingenious or idiotic ??? -- 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 geoengineering+unsubscr...@googlegroups.commailto:geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.commailto:geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout. -- 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 geoengineering+unsubscr...@googlegroups.commailto:geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to
RE: [geo] Mitigate the sea-level rise
Stephen and Greg,This kind of discussion, a trade-off of (doomed) local environment to preserve some global environment, helps educate people about the need for action. It's useful to check how "doomed" are the local environments. For example does the clay barrier between the Mediterranean Sea and the Sahara extend above sea level everywhere? If there are above-sea gaps in the clay, how much sea level rise before the Sea flows into the gap? Or what combination of sea level rise, high tide, and storm surge starts the flooding of land which is already below sea level (Dead Sea, Salton Sea, California Delta, etc.)?Thoughts on a meter of sea level mitigation via low groundwater tables or low ground:1) We can generate hydropower energy as water flows from high to low. When generating energy, pressure is more important than flow rate because turbine efficiency is so much better above about 50 meters of water head than with lower pressure water. Is the future energy income sufficient to "buy" all the affected and doomed property or pay for the personal desalters Stephen and Greg mention? Should we build solar stills which are so large and high we can recover hydropower energy as the water drains off them?2) It is more difficult to push water into an aquifer than to suck water out. However, advances in directional drilling and hydrofracturing (oil and gas drilling technology) might be helpful for increasing percolation into the aqufer.3) We can maintain gravity flow of water in a pipe even if long distances of the pipe are nearly 10 meters above sea level. That is as long as the pipe inlet is in the sea and the outlet is below sea level. Normally, gases in the water come out of solution and this off-gasing is why every pipe "high point" requires an air release valve. I encountered just this high-point-too-high issue and fixed it with a tiny vacuum pump sucking on the air release valve.MarkStephen's comment:Water runs down hill. If you look at the rock porosity and the depths of the water table below the Sahara you can see that we could store a world-metre of sea water down there. So why does it not flow down of its own accord? Answer because ooze on the sea bed in the oceans surrounding the Sahara has clogged the entrances to all the subterranean passages. All we have to do is some ooze-scraping to clear the blockage. Water below the Sahara is already extremely saline. We would have to provide solar-powered desalination plant for every man, woman, child, camel and goat but that would be much cheaper than building a flood wall round Manhattan let alone all the other coastal cities.I have been working on designs of wave-powered scrapers so we can do it without releasing any carbon from fossil fuel. If we can wash the salt it might be quite valuable.Greg's comment: Relatedly, there is an interesting scheme (being tested/built in the Middle East somewhere) that I think goes like this. A natural or artificial marine bay is covered with a high arching cover such that during the day the enclosed space is solar heated and seawater evaporates. During the night the cover naturally cools, freshwater condenses on the inside, trickles down the inside of the cover and is collected to water fields, etc. If water is collected high enough it could be sent inland via gravity/pipe (+- hydroelectric generation?). OK, probably won't stem sea level rise, but might do some good in the meantime, pending GE governance approval. From: geoengineering@googlegroups.com [geoengineering@googlegroups.com] on behalf of Mick West [m...@mickwest.com] Sent: Friday, May 30, 2014 9:16 AM To: celso...@gmail.com Cc: geoengineering Subject: Re: [geo] Mitigate the sea-level rise The world's largest pump does 150,000 gallons a second, and costs around $500 Million, and is only pumping a few feet. http://www.popsci.com/scitech/article/2009-08/saving-new-orleans-worlds-largest-water-pumpTo offset 1 cm of sea level rise, this pump would have to run for 200 years. http://www.wolframalpha.com/input/?i=%28360+million+km2+*+1+cm%29+%2F+%2815+gallons%29+seconds+in+yearsOr you could have 200 pumps do 1cm per year, at a baseline cost of $100 Billion. But if you factor in distance and evaporation you'd probably need a lot more. Combined with the likely saturation of the area with only a small fraction of the 1cm worth of water, the destruction of the local ecosystem, and the need for continued pumping - I'd say this idea is a non-starter. MickOn Thu, May 29, 2014 at 7:54 AM, Celsus celso...@gmail.com wrote: I posted the following a few years ago . I'm putting it out again to see if there's further reactionThe following is so simple and obvious, perhaps it's not so obvious !It's low-tech anduses a large hammer to help crack a very large nut. It will not solvethe problem of sea-level rise, but might mitigate it somewhat. Majornegative side affects are envisaged - more about that later. The idea is to use brute force to
