Hello again Dave,
As I'm sure you know, Bernie & Kurt were brothers. Through the former
(a very close friend) I met the latter a few times. Both generous &
great people!
Cheers, John.
*************
Quoting "Hawkins, Dave" <dhawk...@nrdc.org>:
> not to be confused with Kurt Vonnegut's ice-nine
>
> ________________________________
>
> From: John Latham [mailto:john.latha...@manchester.ac.uk]
> Sent: Friday, February 20, 2009 2:25 PM
> To: Hawkins, Dave
> Cc: geoengineering
> Subject: Cloud Seeding - State-manufactured snowfall closes 12 highways
>
>
>
> Hello Dave et al,
>
> The role of silver iodide AgI in precipitation formation is to initiate
> the freezing of supercooled water cloud droplets at temperatures (below
> 0C) too warm for freezing of such small particles to occur naturally. It
> works well because the molecular bond-length in AgI is very close to
> that in ice, as Bernard Vonnegut (originator of this seeding technique)
> first noticed. The tiny ice particles grow rapidly in the supersaturated
> cloud, acquiring classical hexagonal shapes. These ice crystals collide
> and aggregate to form snowflakes, which eventually settle to ground. I
> cannot see where "moisture retention" comes into the equation.
>
> Silver iodide does not act as a nucleus for water drop formation (only
> for ice).
>
> Cheers, John.
>
>
> ***************
>
>
> Quoting "Hawkins, Dave" <dhawk...@nrdc.org>:
>
>> Whoops.
>> (but consider the mitigation due to a day or so of no driving) :>)
>>
>> CHINA: State-manufactured snowfall closes 12 highways (02/20/2009)
>>
>>
>>
>> Chinese officials were forced to close 12 highways in the
>> drought-plagued Hebei province around Beijing after artificially
>> "enhanced" clouds dropped heavy snowfall, the state-run news agency
>> said.
>>
>> The clouds were seeded by 313 cigarette-sized capsules of silver
> iodide
>> shot into the sky, a procedure to increase the clouds' ability to
> retain
>> moisture.
>>
>> On the bright side, officials expect the snowstorm to help bring an
> end
>> to Beijing's longest drought in 38 years, according to weather bureau
>> records.
>>
>> "The snow has brought moisture to the soil, which may help end the
>> drought," Guo Yingchun, a senior engineer in the provincial
>> meteorological observatory, was quoted as saying.
>>
>> In all, 12 outbound highways were shut down, including one linking the
>> capital with Shenyang, capital of the northeastern Liaoning province
>> (Nick Macfie, Reuters
>> <http://in.reuters.com/article/environmentNews/idINTRE51I10X20090219>
> ,
>> Feb. 19).
>>
>>
>>
>> >
>>
>
>
>
> --
> John Latham
>
> lat...@ucar.edu & john.latha...@manchester.ac.uk
>
> Tel. 303-444-2429 (H) & 303-497-8182 (W)
>
>
> >
>
--
John Latham
lat...@ucar.edu & john.latha...@manchester.ac.uk
Tel. 303-444-2429 (H) & 303-497-8182 (W)
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