Hi Andrew, 1. I think that "polar geoengineering" might be more appropriate than "hydrological geoengineering". Hydrology suggests water resources, but we want to concentrate on critical processes occurring principally in polar regions, because here there are some of the most worrying tipping points (indeed, I fear the Arctic sea ice is already tipping and could be near the point of no return). I'm not sure we need a separate entry for this. Saving the Arctic sea ice is a potential application of geoengineering; similarly dealing with ice sheet meltwater and dealing with methane from permafrost are potential applications of geoengineering.
2. I was fascinated when I heard about pykrete recently, and have been thinking about possible applications for saving the Arctic sea ice. I've added an alternative idea for plugging the moulins, and that is using pykrete, for which there is already a useful wikipedia entry: www.wikipedia.org/wiki/Pykrete Ideally, the pykrete would be sprayed onto existing ice using a mixture of fibrous material (such as sawdust) and near freezing or perhaps supercooled water. It would be interesting to do some experimentation into whether such a process could be developed. This would use a simple device like a snowgun. About Pykrete itself, you say that the fibre/ice ratio is about 1:25, but the pykrete entry says it is 45% fibre, 55% ice by weight. Which ratio is correct? Also the picture of a pykrete block shows the block as dark brown, and not reflecting like ice, as suggested with ref [3]. The advantage of having floating rafts/islands of pykrete is that they would quickly get covered in snow, and only melt slowly from below. Thus they would last throughout the Arctic summer, if made thick enough. (Much of the thinning of the Arctic sea ice is by melting from below.) If ice breakers were to spread sawdust in the freezing water behind them, this might freeze directly into pykrete, and help preserve the ice to increase the proportion of multi-year ice. Again some experimentation would be interesting. There is an idea from Prof John Shepherd, who BTW is leading the RS geoengineering study, to use a large number of ice breakers to plough up the one-year ice, so the ice on either side of the channel left by the ice breaker is thicker, and melts slower in the summer. Perhaps one could combine these ideas, both ploughing up the ice and forming pykrete in the track left by the icebreaker. Cheers, John ----- Original Message ----- From: "Andrew Lockley" <[email protected]> To: "Geoengineering" <[email protected]> Sent: Sunday, December 28, 2008 3:57 PM Subject: [geo] hydrological geoengineering - new wiki page > > http://en.wikipedia.org/wiki/Hydrological_geoengineering > > built by me using material from Alber Kallio > > Please edit at will > > > > --~--~---------~--~----~------------~-------~--~----~ 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] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
