METEOROLOGICAL SERVICES [Main Title]
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- Title: METEOROLOGICAL SERVICES [Main Title]
- Film Number: AMY 131
- Other titles:
- Summary: Information film about the use of meteorological services in the Royal Air Force.
- Description: The weather affects everybody and everything. Forecasts are essential for flying but they are useful to everyone, world wide. The film shows how forecast data are collected and collated on an international basis, and the measurements and observations necessary to determine the data. ETA, the Central Weather Forecasting Station, compile and issue forecast reports and maps at hourly intervals based on the data for a variety of Agencies, in particular, the RAF. Reel one: Film opens to a rotating globe annotated with high and low pressure isobars. Weather hot or cold, good and bad is a world problem affecting everyone, on land, sea or air. Cut to RAF station where the squadron leader enquires of the meteorological officer the weather conditions over Brussels and northern Europe, which according to the latest data received by teleprinter is not good. The teleprinter is connected to the International Meteorological Organisation established some years ago for the exchange of data between countries world wide. It is an outstanding organisation collating weather data that is available to all via teleprinter irrespective of national languages because the data is encoded into groups of five digit numerals. The film explains the principles of this code which provides the data relating to the location of observing station, cloud type and height and base, wind speed and direction, barometric pressure, air temperatures, dew point, type of low & medium cloud, present & past weather. Examples of the instrumentation used to measure these weather parameters are shown; an observer at a RAF station is reading a variety of devices inside and outside of a Stevenson screen every hour, then sending his observations by teleprinter to Group Headquarters. Similar reports are received from other RAF stations, HM Coastguard, signal stations, lighthouses, all reports are made just before the hour, and retransmitted from the Central Forecasting Station known as ETA. Film cuts to a room full of radio, teleprinter and punched paper tape operators receiving data from all over the northern hemisphere. A collective weather report is sent by the device that each station employed to contribute data, including ETA stations in France, Belgium, Germany and Holland. Synoptic charts are prepared at each ETA station by draughtsmen plotting isobars on an outline map of north western europe, the meteorological data from each station plotted as a series of typographical symbols grouped together at the stations geographical location on the outline map. Thus a universal forecast map is created, totally free of any language barriers. In addition to data received from static locations, data is received from ships, and towards the end of World War Two, aircraft flying routine patterns over the sea, equipped to make visual and instrumental observations. Cut to a Mosquito aircraft (G AE) flying in the thick cloud over Iceland to determine how the depression will develop. The location of thunder and lightning storms is extremely important, and special instrumentation incorporating a 360 O circular cathode ray tube (CRT) developed where a lightning discharge appears on the CRT as a spike of certain orientation. Using the orientations from four other so equipped stations, the location of the thunderstorm is determined by triangulation. Reel two: Accuracy is essential when preparing forecasts, and for this reason the ‘Epicure’ flights are flown west over the sea twice a day from stations around the United Kingdom to measure the vertical changes in pressure and temperature. Film cuts to a Halifax flying a pattern of prescribed heights to measure these variations and the temperature inversion point. During the flight the information is radioed back to the base station for distribution to forecasters. Further measurements are made by Hurricanes flying to 30,000 feet. where the pilot observes cloud type and formation and the height at which vapour trails /icing occurs. Upper air measurements are made by instrumentation carried aloft by balloons released and tracked by observers on the ground. Information from all these sources is used at ETA to prepare isobar maps for weather predictions at ground level and at a variety of heights. Film cuts to the underground control room of Bomber Command as senior officers stand around the Chief Meteorological Officer giving his report at 0900 every day of the year. The chief of Bomber Command is advised of the current strategic situation and is planning for the coming nights raid. The decision about a raid is often decided by a ‘Pamper’ flight made by a Mosquito flying high above cloud level to report visibility, etc in the raid area. The weather conditions at country wide RAF stations is another consideration when large raids are planned. Fog can be a problem for returning aircraft, and it may be necessary to divert to another Station. Film cuts back to the squadron leader enquiring about the weather over Brussels; a WAAF brings the latest weather map; still too bad for flying is the conclusion of the meteorological officer. These maps are compiled by ETA forecasters and relayed to the Air Ministry, the Admiralty, Bomber and Fighter Commands and any organisation dependant upon the weather for operations. Cut to control room, Fighter Command, where the duty controller is watching the developing situation on the plotting table, directing squadrons to deploy with due consideration of the scale of attack and the effect of prevailing weather conditions upon both RAF and enemy aircraft. Reel three: Reel opens with a sign‘Headquarters Transport Command RAF’. A senior Officer is looking at a weather map received from ETA. Addressing the camera he says such maps will always be required in the future for all flights, especially the long flights to the Middle East and America. During the wartime meeting at Yalta, Russia agreed to provide meteorological data to the West but initially in the Russian language. Adoption of the international code at a later date made for easier integration of their meteorological data. Film returns to ETA to see a forecaster is preparing his forecast map, which is also sent to the BBC and national newspapers for dissemination to the general public. ETA broadcasts to Airfields and aircraft in flight to warn of unfavourable or even dangerous conditions ahead. The recognition of cloud types and how their associated properties can effect the weather provides a useful guide to all, particularly pilots. The ten major cloud types are illustrated in the film; high, medium and low clouds, from ground level to over 40,000 feet in height. Film returns again to the squadron leader receiving an updated weather map for the Brussels area, the meteorological officer indicates conditions are not perfect but safe enough for flying. At ETA, the Central Weather Forecasting station, customised reports are prepared for the RAF, civilian airlines, shipping companies, farmers and the general public. Information is collected, analysed and sent out every hour of the 24. Film closes with clips of each customer, and a BBC radio weather forecast for a day in 1940.
- Alternative Title:
- Colour: B&W
- Digitised:
- Object_Number: AMY 131
- Sound: Sound
- Access Conditions:
- Featured Period: 1946-1975
- Production Date: 1947
- Production Country: GB
- Production Details: ROYAL AIR FORCE (Production sponsor) Harvey Harrison films (Production company)
- Personalities, Units and Organisations:
- Keywords:
- Physical Characteristics: Colour format: B&W Sound format: Sound
- Technical Details: Format: 35mm Number of items/reels/tapes: 1 Length: 2059ft
- HD Media:
- Link to IWM Collections page:
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