Dear Denis‹You really need to do some order of magnitude estimating: Based on the earlier email on the energy involved in and dissipated by hurricanes, the heat release of a hurricane (on average‹big ones are higher by a good bit) is on order of 5.2 * 10**19 Joules per day. Convert that to calories, assume you want to dissipate 10% of the energy to slow the storm down a bit (and this would really mean increasing the natural dissipation rate by a factor of 40‹which is lot given that the drag of the surface ocean is now the major sink of drag energy‹that this factor is so large should give you real pause). But any way, to deposit the energy you are talking about as heat in the ocean, your drag devices would have to warm the upper 10 meters of the ocean over an area having a radius of 300 km by roughly 0.3 C‹that is a very great amount (just think how much effort the Sun takes over the seasonal cycle to warm a bit thicker layer by somewhat more). We are talking about huge amounts of energy‹so, on this argument, I am on the side of David saying ³nonsensical.²
Your arguments on CO2 lifetimes, etc. are being addressed by others. Mike On 6/12/09 3:24 AM, "Bonnelle Denis" <dbonne...@ra.ccomptes.fr> wrote: > About this "beyond nonsensical" idea: > > I was just commenting a post which dealt with angular momentum and which > proposed to use kite devices. About this point, I only added the adjective > "strong". About ships, their being submitted to storm winds isn't, indeed, > necessary for my idea: submarines could do the job as well. And they could > more easily move between inside the hurricane's eye - where the surface winds > are weaker - and outside the whole hurricane - where the crew could safely > join the rest of the world. Reversed propellers and other hydrodynamic brakes, > in order to exchange angular momentum, could be fitted to submarines as well > as to ships. > > Their "strength" and the kites' one is a matter of design, but mainly of size > and finally of materials quantities. I do not pretend that I have done the > least beginning of an economic appraisal, but if anyone was willing to, it > would be a good thing. > > Best, > > Denis. > > De : David Schnare [mailto:dwschn...@gmail.com] > Envoyé : jeudi 11 juin 2009 13:09 > À : Bonnelle Denis > Cc : ds...@yahoo.com; geoengineering; lmich...@vortexengine.ca > Objet : Re: [geo] Re: Just in Time for Hurricane Season > > > For those of us who have been on a ship, on the ocean and near a hurricane, > much less under it, the idea of having any ship, much less many of them, > flying kites and reversing engines in some kind of large circle is beyond > nonsensical. It's sort of like having the government control GM - might sound > like a good idea, but really! > > > > d > > On Thu, Jun 11, 2009 at 5:59 AM, Bonnelle Denis <dbonne...@ra.ccomptes.fr> > wrote: > > This analysis is interesting, but I'd split the first sentence in three parts: > "To have harmful wind speeds, a hurricane needs to have a large underpressure > air column in its middle, and this underpressure has to be protected by the > centrifugal force, which results from a lot of angular momentum". > > However, when these ideas are being translated to figures (numbers), an > important parameter comes in : the radius. The centrifugal force effect is > negligible at the beginning of the air path (when Coriolis's force builds the > angular momentum up) and at the end of the same path. It is only in its > middle, i.e. at a middle altitude (maybe from 1000 m to 8000 m) that this > effect is maximum. > > So, if you'd like to use some strong kites to create a drag, a useful device > could be to have some boats along a circle in the hurricane's eye, being drawn > by kites 1000 or 2000 m high, using their propellers as brakes (and even > transmitting some mechanichal power to an electrical engine which would act as > a power generator). This would transfer the hurricane's angular momentum - at > the point where this momentum is most implicated in the hurricane's > self-stability - to the sea, i.e. it would create an interesting angular drag. > > Conversely, I am not very much convinced by angular momentum exchanges with > the upper layer of the hurricane's air. > > Best, > > Denis Bonnelle > denis.bonne...@normalesup.org > > > -----Message d'origine----- > De : geoengineering@googlegroups.com [mailto:geoengineer...@googlegroups.com] > De la part de dsw_s > Envoyé : mercredi 10 juin 2009 10:55 > À : geoengineering > Objet : [geo] Re: Just in Time for Hurricane Season > > > > To have harmful wind speeds, a hurricane needs to have lots of angular > momentum. If some of the angular momentum could be dispersed to > farther from the center of the storm, wind speeds would be lower. If > I understand it right, a hurricane has air coming in from the > periphery at low altitude, rising in the middle, and dispersing at > higher altitude. If the storm is remaining steady or strengthening > (in terms of the total angular momentum of its winds), the outgoing > air must have less angular momentum than the incoming air by an amount > at least equal to the angular momentum lost to drag at the surface. > Suppose we have something for drag suspended at an altitude where air > is moving inward, from balloons at an altitude where air is moving > outward. That should transfer angular momentum from the inward-moving > air to the outward-moving air. > > Alternatively, one could fly over the edges of the storm and drop long > ropes with a kite on one end and on the other end a weight of > approximately the same density of water. The kites would fly > themselves for a while before being destroyed, creating drag and > decreasing the angular momentum of the air they came in contact with. > As the air moved in toward the center of the hurricane, the change in > wind speed would be multiplied according to conservation of momentum > just as the wind speed itself is. > > > > --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
