Hello Mike et al, I agree entirely with you Mike that seeding can cause ice fogs to disperse. Also electrostatic droplet seeding could help dissipate warm fogs. I should have more carefully indicated that I was focusing on seeding of clouds containing ice, and particularly mixed-phase clouds.
Cheers, John. Quoting Mike MacCracken <[email protected]>: > With one exception, I agree with John. The exception is that I think it has > been demonstrated that one can clear an ice fog with seeding, and this has > been done to open airports, etc.--not to generate precipitation (in any > form). > > I would add that the water vapor content of air and clouds above Greenland > is likely so low that one could not be likely to get a significant buildup > of snow. Whether one could seed storms or change sea surface temperatures in > surrounding areas in a way that would lead to greater likelihood of storms > depositing snow on Greenland (or Antarctica, etc.) has not, to my knowledge, > been looked at at all. > > Mike > > > On 12/16/09 4:00 AM, "John Latham" <[email protected]> wrote: > >> Hello Neil, Andrew et al. >> >> Cloud seeding (principally to make rain) has had a long and highly chequered >> history in the 60 years since Vonnegut, Schaefer & Langmuir did their >> pioneering work. Many studies since then were contaminated by commercial >> interests. There is no essentially no consensus as to whether and under what >> circumstances it will work. This is especially true for clouds that contain >> ice. Whether seeding will enhance, reduce or have negligible effect on such >> clouds depends on: atmospheric stability, cloud-base temperature, updraught >> speed, presence or absence of conditions in which natural secondary can >> function, level and location etc etc. I think there is good reason to feel >> sceptical of studies reporting quantitative estimates of changes induced by >> seeding. My view is that - as with several geoengineering schemes - what is >> urgently required is well-controlled , comprehensive field experiments. Only >> then will it be possible to establish whether cloud seeding might, on a >> regional scale, be important vis-a-vis climate change. >> >> Cheers, John. >> >> >> ******************************** >> >> Quoting Neil Farbstein <[email protected]>: >> >>> > I'm glad we agree. Small cloud seeding experiments over Greenland >>> > should be practical. We should give this some thought and modeling. >>> > Can you do that at your lab? Google satellite pictures and weather >>> > satellites can locate clouds that are likely targets to seed; The >>> > bigger clouds in the places that are most strategic. >>> > An international organization or groups of industrialized nations can >>> > pay the local residents or the greenland government subsidies for >>> > participating in the cloud seeding program. >>> > >>> > On Dec 15, 8:27 pm, Andrew Lockley <[email protected]> wrote: >>>> >> For clarity, the main reason my for suggesting cloud seeding is that it >>>> can >>>> >> be used to build up greenland to a height where the air temperature is >>>> low >>>> >> enough to sustain the ice sheet. The could potentially reverse the >>>> >> catastrophic Greenland tipping point - which will unleash >>>> several metres > of >>>> >> sea level rise over a few hundred years. Game over for London, Venice, >>>> >> Florida, New York, etc. if that happens. Worth a bit of jet fuel or a >>>> few >>>> >> rockets to prevent that, I'd argue. >>>> >> >>>> >> A >>>> >> >>>> >> 2009/12/15 Neil Farbstein <[email protected]> >>>> >> >>>> >> >>>> >> >>>>> >> > I suggested the same cloud seeding strategy a month ago. Somebody >>>>> >> > authoritative said that the biggest snowfall recorded over the >>>>> >> > alaskan arctic caused the biggest melt water recorded during the >>>>> >> > spring. That's anecdotal evidence but I dropped the idea of >>>>> working on >>>>> >> > that anyway. >>>> >> >>>>> >> > There wont be a melt water problem if clouds are seeded over large >>>>> >> > parts of the gulfstream to cool it and the winds that blow off it. >>>> >> >>>>> >> > On Dec 15, 5:47 am, Andrew Lockley <[email protected]> wrote: >>>>>> >> > > I note the use of cloud seeding by the Chinese, and its >>>> >> unexpected effect >>>>> >> > in >>>>>> >> > > causing huge snowfalls in Beijing. It seems that there may be >>>> >> two useful >>>>>> >> > > geoengineering approaches with this technique, and I'd be >>>>>> interested in >>>>>> >> > > hearing comments. >>>> >> >>>>>> >> > > 1) Rebuild ice - by inducing snowfalls over Greenland, >>>> >> Antarctica and the >>>>>> >> > > Arctic, it would perhaps be possible to maintain ice. In >>>>>> Greenland, >>>>> >> > where >>>>>> >> > > the height of the ice cap is critical, this would seem a >>>>>> particularly >>>>>> >> > > appealing prospect. >>>>>> >> > > 2) Albedo modification - Fresh snow is whiter than old snow, >>>>>> especially >>>>> >> > in >>>>>> >> > > polluted areas. Is the albedo change worth pursuing? My >>>>>> guess is > not. >>>>>> >> > > HOWEVER, I suspect that triggering significant autumn and spring >>>>> >> > snowfalls >>>>>> >> > > in permafrost regions, we could potentially significantly modify >>>>>> albedo. >>>> >> >>>>>> >> > > I invite comments. >>>> >> >>>>>> >> > > A >>>> >> >>>>> >> > -- >>>> >> >>>>> >> > 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]<geoengineering%2bunsubscr...@go >>>> oglegroups.com> >>>>> >> > . >>>>> >> > For more options, visit this group at >>>>> >> >http://groups.google.com/group/geoengineering?hl=en.- Hide >>>>> quoted text > - >>>> >> >>>> >> - Show quoted text - >>> > >>> > -- >>> > >>> > 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. >>> > >>> > >>> > >> >> >> >> > > -- John Latham [email protected] & [email protected] Tel. 303-444-2429 (H) & 303-497-8182 (W) -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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