> in the hurricane's eye That misses the whole point of the idea. The first law of hurricane management is that you can't do anything to a hurricane's energy directly: you need something that multiplies the effectiveness of your intervention, because otherwise the amounts of energy involved are just too big. The multiplier might be that each tiny cloud condensation nucleus helps form a droplet many times its own mass, to reflect light so the sea surface doesn't warm as much. It might be that removing a little energy causes many times more energy to be dissipated in turbulence or just not converted from thermal to mechanical energy.
The multiplier here is that a small change in momentum produces a large change in angular momentum when the distance to the center of rotation is large, corresponding to a larger change in momentum closer to the center. So you have to apply the drag near the edges of the storm. That has the added benefit that it takes longer to destroy your kites in an area of lower wind speed. On Jun 11, 7:09 am, David Schnare <[email protected]> wrote: > 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 > <[email protected]>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 > > [email protected] > > > -----Message d'origine----- > > De : [email protected] [mailto: > > [email protected]] 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. > > -- > David W. Schnare > Center for Environmental Stewardship --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
