RAF rainmakers 'caused 1952 flood'
Andrew Lockley
Poster's note : this historical news piece almost certainly incorrectly points the finger of blame - a large low pressure system and a cold front combined to cause the flood. Nevertheless, it's instructive of the controversies we can expect in a geoengineered world.
RAF rainmakers 'caused 1952 flood'
John Vidal and Helen Weinstein
Published: 10:56 GMT+01:00 Thu 30 August 2001
On August 15, 1952, one of the worst flash floods ever to have occurred in Britain swept through the Devon village of Lynmouth. Thirty five people died as a torrent of 90m tons of water and thousands of tons of rock poured off saturated Exmoor and into the village destroying homes, bridges, shops and hotels.
The disaster was officially termed "the hand of God" but new evidence from previously classified government files suggests that a team of international scientists working with the RAF was experimenting with artificial rainmaking in southern Britain in the same week and could possibly be implicated.
Squadron Leader Len Otley, who was working on what was known as Operation Cumulus, has told the BBC that they jokingly referred to the rainmaking exercise as Operation Witch Doctor.
His navigator, Group Captain John Hart, remembers the success of these early experiments: "We flew straight through the top of the cloud, poured dry ice down into the cloud. We flew down to see if any rain came out of the cloud. And it did about 30 minutes later, and we all cheered."
The meteorological office has in the past denied there were any rainmaking experiments conducted before 1955, but a BBC Radio 4 history investigation, to be broadcast tonight, has unearthed documents recently released at the public record office showing that they were going on from 1949 to 1955. RAF logbooks and personnel corroborate the evidence.
Until now, the Ministry of Defence has categorically denied knowledge of any cloud-seeding experiments taking place in the UK during early August 1952. But documents suggest that Operation Cumulus was going on between August 4 and August 15 1952. The scientists were based at Cranfield school of aeronautics and worked in collaboration with the RAF and the MoD's meteorological research flight based at Farnborough. The chemicals were provided by ICI in Billingham.
Met office reports from these dates describe flights undertaken to collect data on cumulus cloud temperature, water content, icing rate, vertical motions and turbulence, and water droplet and ice crystal formation. There is no mention of cloud seeding.
But a 50-year-old radio broadcast unearthed by Radio 4 describes an aeronautical engineer and glider pilot, Alan Yates, working with Operation Cumulus at the time and flying over Bedfordshire, spraying quantities of salt. He was elated when the scientists told him this had led to a heavy downpour 50 miles away over Staines, in Middlesex.
"I was told that the rain had been the heaviest for several years - and all out of a sky which looked summery ... there was no disguising the fact that the seedsman had said he'd make it rain, and he did. Toasts were drunk to meteorology and it was not until the BBC news bulletin [about Lynmouth] was read later on, that a stony silence fell on the company," said Mr Yates at the time.
Operation Cumulus was put on hold indefinitely after the tragedy.
Declassified minutes from an air ministry meeting, held in the war office on November 3, 1953, show why the military were interested in increasing rain and snow by artificial means. The list of possible uses included "bogging down enemy movement", "incrementing the water flow in rivers and streams to hinder or stop enemy crossings", and clearing fog from airfields.
The documents also talk of rainmaking having a potential "to explode an atomic weapon in a seeded storm system or cloud. This would produce a far wider area of radioactive contamination than in a normal atomic explosion".
UK weather modification experiments at the time presaged current practice in the US. The idea was to target "super cool" clouds, and to increase the volume of freezing water vapour particles. Most methods involved firing particles of salt, dry ice, or silver iodide, into clouds, either from an aeroplane or from burners on the ground. The clouds would then precipitate, pulled down below freezing point by the extra weight of dense particles, thus making it rain sooner and heavier than it might have done. Significantly, it was claimed that silver iodide could cause a downpour up to 300 miles away.
Many countries now use the technology, which has considerably improved during the past 50 years.
But controversy still surrounds the efficacy of these early cloud-seeding experiments. In 1955 questions were asked in the Commons about the possibilites of liability and compensation claims. Documents seen by the BBC suggest that both the air ministry and the Treasury became very anxious and were aware that rainmaking could cause damage, not just to military targets and personnel, but also to civilians.
The British Geological Survey has recently examined soil sediments in the district of Lynmouth to see if any silver or iodide residues remain. The testing has been limited due to restrictions in place because of foot and mouth disease, and it is inconclusive. However, silver residue has been discovered in the catchment waters of the river Lyn. The BGS will investigate further over the next 18 months.
Survivors of the Lynmouth flood called for - but never got - a full investigation into the causes of the disaster. Rumours persist to this day of planes circling before the inundation.
Alan Gadian
Andrew,
There is one (scientist) person left alive who participated in the
work on the mission which was related to the Lynmouth floods.
If you believe that Newton's laws of motion, and the Navier Stokes
equations are applicable in the atmosphere, then there can be no
connection between flights over Salisbury Plain and Lynmouth. Boscastle
was a similar storm for possibly similar generating factors .. not to
mention the Boltby storm last deacde.
Alan
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--
s-
Alan Gadian
Senior Scientist, NCAS, Environment, Leeds University, LS1 9JT , UK
Email: al...@env.leeds.ac.uk or ala...@gmail.com
Tel: (+44)/(0) 113 343 7246 Mobile: (+44)/(0) 775 451 9009
s-
Chris Burgoyne
I use the Lynmouth floods as the basis for a discussion with
students about what you should design bridges for.
The Lynmouth flood was exceptional on many levels. It is well
described in a paper in the Inst of Civil Engineers. THE LYNMOUTH FLOOD
OF AUGUST 1952. C
H DOBBIE; P
O WOLF, ICE Proceedings: Engineering Divisions,
Volume 2, Issue 6,
01 December 1953
,
pages
522–546.
For those who don't know the background, Devon gets lots of
storms coming in from the Atlantic, many of which are quite
localised. The rivers that flow north into the Bristol Channel
are very short, and very steep, which means they have very short
rise times - a few hours max. There was a very intense storm on
15th Aug 1952 over Exmoor, with as much as 250 mm rain in a
short period (there is no exact data because there were very few
gauges); this figure was obtained by back calculation. About
half of the area drained into the East and West Lyn rivers,
which are less than 10 km long, and produced run off intensities
of about 7 m^3/s/km^2 from a catchment of about 100 km^2, which
compares with the expected mean annual flood of about 0.4
m^3/s/km^2. The village had started life as a small fishing
community as an adjunct to Lynton (which lies on the high ground
above the valley), but had expanded into a resort in Victorian
times, much of it built on the only flat land available, which
was next to the river and in reality was part of its natural
flood course. The river reclaimed its own and washed away many
buildings with great loss of life (it struck at night while many
people were in bed). The village was rebuilt with a much wider
channel and much bigger bridges. My father was an engineer and
worked on the rebuilding.
The 1952 storm was described as a "1 in 1000 years event", but
interestingly there was another flood in about 1956/7 that was
almost as high. I have seen it described as a "1 in 975 year
event" in a paper that I can no longer find but would love to be
able to get hold of, but this caused no problems because a much
bigger channel had been provided. My father described seeing
the water only a few inches below the soffits of the new
bridges. I use this example to show students that just because
you have had one very rare event, it doesn't mean that you can't
have another very soon afterwards.
There are reports of a similar flood about 150 years earlier,
and there have been other floods nearby, notably at Boscastle in
Cornwall, which has a similar river profile and catchment.
I agree with Andrew that the RAF were almost certainly not
responsible for the flood. They were apparently seeding clouds
over Salisbury Plain, well to the east, and the storm came from
the west. But mud sticks and geoengineering is expected to
disrupt climate patterns, which makes even more clear that we
should do the research to find out what the issues are and then
get the governance sorted out before we attempt anything for
real.
Chris Burgoyne
--
Jamais Cascio
Poster's note : this historical news piece almost certainly incorrectly points the finger of blame - a large low pressure system and a cold front combined to cause the flood. Nevertheless, it's instructive of the controversies we can expect in a geoengineered world.
..."viral sovereignty." This extremely dangerous idea comes to us courtesy of Indonesia's minister of health, Siti Fadilah Supari, who asserts that deadly viruses are the sovereign property of individual nations -- even though they cross borders and could pose a pandemic threat to all the peoples of the world.