It seems completely implausible that we would wait until a hurricane is about to make landfall and then try to destroy it somehow. The fact that a hurricane can extract energy from the temperature difference between sea surface and upper troposphere means that the atmosphere is conditionally unstable. So if we can start convection when there's no hurricane anywhere near, the convection should be self- sustaining at least until wind shear disperses it. Specifically I imagine my flying plastic sheets maneuvering into a stack to heat a whole column of air so that convection can get started.
On Jun 14, 4:01 pm, dsw_s <[email protected]> wrote: > > You need to get more creative... > > Ok, shall we talk pie in the sky? Let's get a decent-sized mostly- > stony asteroid, say a few hundred cubic kilometers, into earth orbit > and drop chunks of it into the atmosphere, controlling the size and > composition of the chunks so that they'll produce dust of the desired > particle size at the desired altitude. Dust high in the atmosphere > can absorb sunlight so that the air is heated instead of the ground. > Dust lower in the atmosphere provides CCN. The rock will weather to > carbonate, to both remove CO2 and counteract acidification. > > And if we want to break up a hurricane that's already formed, we can > drop kiloton-equivalent meteors into it at one per second for a few > hours to set up a different convection pattern that conflicts with the > original circulation and disperses the kinetic energy in turbulence. > > On Jun 14, 9:10 am, "Peter Read" <[email protected]> wrote: > > > Another good thing from cooling the oceans is we can do it upwind of the > > coral reefs and help them stay alive. > > > But, besides overheating, the acidity is also killing them. > > > So we also need to get C out of the linked oceans-atmosphere as well, and > > put it somewhere safer. Injecting sulphur aerosols in Polar regions cannot > > do that and may exacerbate the threat to monsoons. > > > Safely stocking C in terrestrial storages will cause the land to cool > > faster than the oceans because of the high thermal mass of surface water > > (not to mention mixing of ocean surface layers). And that will threaten > > the convective circulation that advects moist ocean waters over the land, > > to cause the tropical monsoons that sustain agriculture in India and > > elsewhere. > > > So we need to cool the oceans enough to keep the monsoons going, as well > > as, with luck, to calm down the hurricanes. > > > Any of those climate modelers out there working out what needs to be done, > > in terms of combined global greenhouse gas level reductions and local > > albedo modifications, to give us climatic safety (which I have suggested > > can only be secured by limiting cumulative warming, roughly measured as the > > integral under the greenhouse gas concentration profile minus the spatial > > and temporal integral of albedo modification?) > > > Cheers > > Peter > > > ----- Original Message ----- > > From: John Latham > > To: [email protected] > > Cc: dsw_s ; Geoengineering > > Sent: Sunday, June 14, 2009 4:04 PM > > Subject: [geo] Re: Just in Time for Hurricane Season > > > You are right, of course, Mike! > > > Cheers, John. > > > Quoting Mike MacCracken <[email protected]>: > > > > Hi John—I certainly agree with you for dealing with storms generally—not > > > sure you could do for a particular storm, which is what the > > > question/suggestion related to. > > > > On 6/13/09 11:33 PM, "John Latham" <[email protected]> > > wrote: > > > >> Hello All, > > > >> A further possibility is to attempt to emasculate incipient hurricanes > > by > > >> cooling oceanic surface waters in regions where hurricanes spawn. One > > way of > > >> doing this would be to seed low-level shallow clouds in appropriate > > >> regions so > > >> as to increase their droplet number concentration and thereby their > > albedo. > > >> Exploratory GCM exploration of this idea yields the highly > > >> provisional result > > >> that a cooling of one or two degrees (perhaps more) could possibly be > > >> achieved: which could be significant vis-a-vis hurricane development.. > > > >> Other cooling ideas could prove to be of importance. > > > >> Cheers, John. > > > >> Quoting Mike MacCracken <[email protected]>: > > > >>> > You need to get more creative. Lowell Wood's idea some decades ago > > was > > >>> > orbiting mirrors in space that would redirect sunlight on to the > > >>> storm. The > > >>> > problem remains, however, storm energy is huge, and it is not at > > >>> all clear > > >>> > that such efforts could trigger a change, much less one would want > > and be > > >>> > able to predict. > > > >>> > Mike M > > > >>> > On 6/13/09 6:35 PM, "dsw_s" <[email protected]> wrote: > > > >>>> >> Does a hurricane live moment-to-moment, running entirely on the > > power > > >>>> >> it dissipates? Or does it accumulate energy, and have its > > ability to > > >>>> >> release energy depend not only on how much it's dissipating but > > also > > >>>> >> on how much it has accumulated? > > > >>>> >> If it depends on accumulated energy, an intervention only has to > > >>>> >> affect an amount of power on the order of the difference between > > power > > >>>> >> in and power out. If an intervention can make even a small > > difference > > >>>> >> in energy accumulation rate, then having it run for a long time > > would > > >>>> >> make a larger difference in the amount of energy accumulated. > > > >>>> >> My latest thought is to warm the top of the hurricane by > > suspending > > >>>> >> sheets of black plastic in the air. If we could suspend a square > > >>>> >> kilometer of plastic sheet, the sunshine heating it would be less > > than > > >>>> >> the power the hurricane dissipates by a factor of something like > > >>>> >> 10**7. That's still a lot of effect-multiplier needed: > > brute-force > > >>>> >> alteration of the whole hurricane is out of the question, as > > always. > > >>>> >> A good choice of where to heat the air might let us decrease the > > >>>> >> efficiency with which the storm turns the dissipated heat into > > >>>> >> mechanical work. One way to get some multiplier effect might be > > to > > >>>> >> use a bunch of smaller sheets to nucleate convection cells and > > turn a > > >>>> >> region of just-barely-stable air into a region of scattered > > cumulus > > >>>> >> clouds. Maybe the same thing could be done in the area where > > >>>> >> hurricanes form: instead of having convection cells merge into a > > >>>> >> tropical depression, perhaps they could be managed so that there > > would > > >>>> >> be enough room for air to sink in between the cells. Or we could > > go > > >>>> >> the opposite way, making tropical depressions form at the very > > >>>> >> beginning of the season or at the fringes of the area of hurricane > > >>>> >> formation, so that they grow only into moderate tropical storms > > >>>> >> instead of strong hurricanes, and then the sea surface would be > > cooler > > >>>> >> when hurricanes pass over it. > > > >>>> >> Replacing a few powerful hurricanes with a larger number of weak > > >>>> >> tropical storms could be a part of overall geoengineering: the > > smaller > > >>>> >> storms might mix less heat down into the ocean, so that less heat > > is > > >>>> >> transported to the poles. > > > >>>> >> On Jun 12, 8:42 am, Mike MacCracken <[email protected]> wrote: > > >>>>> >>> 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" > > >>>>> <[email protected]> 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, > > > >>>>>> > > ... > > read more » --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
