Rain Making
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Joined: Oct 2003
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From: Canberra Australia
Rain Making
I have had some experience and success with Rain Making by seeding clouds with Silver Iodide crystals generated from a small underwing burner.
Has anyone out there had similar experience and with what success?
Most of Oz is getting fairly desperate for rain and could do with something better than rain dances.
Has anyone out there had similar experience and with what success?
Most of Oz is getting fairly desperate for rain and could do with something better than rain dances.
Joined: Jun 2000
Posts: 111
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From: RAF Lincolnshire
Milt,
we tried it in the UK in the 1950s and 1960s, but with very mixed and inconclusive results. Many papers published on the experiments. The largest experiment was carried out by Imperial College London in 1953, called operation CUMULUS, flying out of Cranfield airfield.
Of late, several commercial companies in the USA have made quite spectacular claims, that do not seem to stand up to independent peer reviewed examination, apart from one experiment carried out in the late 1990s over Mexico.
The Russians and Isrealis have also tried of late, again with mixed results.
Search some of the Meteorological litrature and you will turn up all sorts of refrences.
we tried it in the UK in the 1950s and 1960s, but with very mixed and inconclusive results. Many papers published on the experiments. The largest experiment was carried out by Imperial College London in 1953, called operation CUMULUS, flying out of Cranfield airfield.
Of late, several commercial companies in the USA have made quite spectacular claims, that do not seem to stand up to independent peer reviewed examination, apart from one experiment carried out in the late 1990s over Mexico.
The Russians and Isrealis have also tried of late, again with mixed results.
Search some of the Meteorological litrature and you will turn up all sorts of refrences.
Joined: Dec 2000
Posts: 55
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From: Canada
There is an operation in Calgary that seeds clouds in the Spring and early Summer as a method of controlling hailstorms. The purpose is to provoke precipitation prior to the hailstones getting to the size where they cause damage. They use a light twin to seed. I heard it was funded by a group of insurance companies. They have had some fairly major incidents of damage in the past.
See link below
http://www.bbsr.edu/rpi/meetpart/nov00/smith/
Regards
See link below
http://www.bbsr.edu/rpi/meetpart/nov00/smith/
Regards
Joined: Apr 2004
Posts: 46
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From: cambridge
Yes, there is a documentary running on Discovery Wings at the moment regarding the aforementioned Weather Pilots.
Three types:
One set fly above 'feeder clouds' spraying silver iodide into the clouds.
One set fly above the clouds with flares, putting the stuff into the rising moisture, forming the clouds.
One set fly directing near to the epicentre of the storm (and the documentary footage shows some crazy turbulence +/- 6000 ft updrafts!), spraying similar chemicals.
The effect of these is to remove the oxygen from the air (correct me if I'm wrong), meaning there is less oxygen to form water....and thus hail. So, hail DOES come down, but in smaller pieces.
You're right, it was a result of insurance companies asking for the flying to be done, to avoid expensive insurance payouts.
This area near Calgarry is known as hail alley, and they get football-sized chunks come down weekly.
The job looked fantastic though - turbulent flights every day! The aircraft took an inevitable battering however, with bits falling off everywhere.
The best thing was that environmentalists couldn't complain - they weren't affecting the weather patterns...just the size of the hail.
There is a great photo of the trials for this thing, where someone flew a figure of 8 above a cloud formation. The photo of the resulting cloud shows where the silver iodide caused the clouds to 'collapse' in on themselves.
Incidentally, does anyone know - isn't silver iodide the stuff they use on camera film?
Three types:
One set fly above 'feeder clouds' spraying silver iodide into the clouds.
One set fly above the clouds with flares, putting the stuff into the rising moisture, forming the clouds.
One set fly directing near to the epicentre of the storm (and the documentary footage shows some crazy turbulence +/- 6000 ft updrafts!), spraying similar chemicals.
The effect of these is to remove the oxygen from the air (correct me if I'm wrong), meaning there is less oxygen to form water....and thus hail. So, hail DOES come down, but in smaller pieces.
You're right, it was a result of insurance companies asking for the flying to be done, to avoid expensive insurance payouts.
This area near Calgarry is known as hail alley, and they get football-sized chunks come down weekly.
The job looked fantastic though - turbulent flights every day! The aircraft took an inevitable battering however, with bits falling off everywhere.
The best thing was that environmentalists couldn't complain - they weren't affecting the weather patterns...just the size of the hail.
There is a great photo of the trials for this thing, where someone flew a figure of 8 above a cloud formation. The photo of the resulting cloud shows where the silver iodide caused the clouds to 'collapse' in on themselves.
Incidentally, does anyone know - isn't silver iodide the stuff they use on camera film?
Joined: Nov 2002
Posts: 55
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From: a radar shadow
Rainmaking?
In my opinion, weather modification does work. However, wxmod won't work if you don't have clouds that can produce precip...
I remember running under a line of cu, dispensing AgI from burners under our wing. At the end of the line of cumulus, we did a 180 and saw the first cloud had a rainshaft under it. Our ground radar reported that they could see echos forming where we had been seeding.
Haven't seen the Discovery Wings show (no TV) but noted some differences between our operation and what Bazzaman96 describes.
In our op, some aircraft flew under the feeder clouds, dispensing AgI from underwing burners into the updrafts. Another aircraft flew at the -10C level (usually 17,500 - FL210), dropping either dry ice pellets or AgI flares into the tops of feeder clouds. We avoided the center of the storm like the plague - as mentioned, severe turbulence as well as the fact that seeding is ineffective there.
The Alberta operation uses Piper Cheyennes, and this website may have some interesting information, as well as more info on the Alberta operation for you.
I remember running under a line of cu, dispensing AgI from burners under our wing. At the end of the line of cumulus, we did a 180 and saw the first cloud had a rainshaft under it. Our ground radar reported that they could see echos forming where we had been seeding.
Haven't seen the Discovery Wings show (no TV) but noted some differences between our operation and what Bazzaman96 describes.
In our op, some aircraft flew under the feeder clouds, dispensing AgI from underwing burners into the updrafts. Another aircraft flew at the -10C level (usually 17,500 - FL210), dropping either dry ice pellets or AgI flares into the tops of feeder clouds. We avoided the center of the storm like the plague - as mentioned, severe turbulence as well as the fact that seeding is ineffective there.
The Alberta operation uses Piper Cheyennes, and this website may have some interesting information, as well as more info on the Alberta operation for you.
