Reference: The Meteorological Office and The First World War
Original published in The Meteorological Magazine , Volume 84, No. 996, June 1955, pp.173-178. © Crown Copyright. Link to original . As sourced and provided by the National Meteorological Library and Archive — Met Office, UK. Reproduced here under the Open Government Licence.
THE METEOROLOGICAL OFFICE AND THE FIRST WORLD WAR
By E. GOLD, D.S.O., F.R.S.
The first outstanding impact of meteorology on military operations in the war arose from the bombing of east coast towns by Zeppelins (airships) in the spring of 1915. In those days there was no observation of upper winds in, or above, a cloud layer, and very little on other occasions. The only effective guide to the upper wind was the geostrophic wind (gradient wind as it was then called). It was clear as daylight from the synoptic charts, even reduced as they were, that the Zeppelins had been carried north and east of their target, London, by a SW. geostrophic wind of which they had no knowledge prior to, or during, their passage across the North Sea. When the Director, Dr Shaw, brought this to the notice of the appropriate authorities, they began to think more seriously of meteorology as a factor in war.
(It was a later disaster to Zeppelins, on October 19, 1917, through failure to allow for the effect of a warm air mass to the west in turning a weak southerly wind at low levels into a strong northerly wind at very great heights, that was the occasion of my origination of the term "thermal wind".)
Almost simultaneously with the 1915 Zeppelin event, occurred the German gas attack near Ypres, in violation of the convention to which Germany was a party, prohibiting the use of gas in war. At that time a gas attack could be made only with a wind which would drift the gas released from cylinders in the direction of the enemy and do so without dispersing it too rapidly to let it reach the enemy in effective concentration. Thus the decision to retaliate naturally brought meteorology directly into the field of British offensive military operations, and the need for a meteorological service with the Army in France, obvious to the meteorologists, became clear also to the soldiers.
After the outbreak of war, July 28 — August 4, 1914, the meteorological information received was limited to that from the British Isles and France, and some reports from Spain and, later, from Scandinavian countries. At first forecasts continued in the Press and the Daily Weather Report was issued, though subsequently issue to the public was only after a fortnight's interval, and publication of forecasts in the Press was stopped. Meteorological information for the British Expeditionary Force in France was supplied direct from the Meteorological Office in London (without any adequate reports of conditions in the area of operations in France). Now a detachment — or rather a couple of officers — was to be sent to France. They were described as the "Meteorological Field Service", which in fact they grew into, though the name was changed within a few months to Meteorological Section R.E. and abridged generally to "Meteor".
The general organization of the military meteorological services was in the charge of Maj. H. G. Lyons, R.E. acting for the Director of the Meteorological Office. The staff of the Field Service for France consisted of a meteorologist of the rank of Captain (E. Gold), and a professional assistant of the rank of Lieutenant (A. E. M. Geddes), the latter "for upper wind observations", commissioned in the General Infantry, and stationed at General Headquarters. Technical or clerical assistance was to be provided by the Army in France. There were to be reserve officers at "Home" ready to exchange duty with the staff on Field Service.
Briefly the major functions of the service as then visualized by the military authorities were to provide: (a) meteorological information for offensive gas operations and defence against enemy gas operations (this was primarily existing and expected direction and strength of the surface wind); (b) forecasts for "battles", wind, weather, cloud and, later, visibility; (c) meteorological information for the Royal Flying Corps, mainly cloud and wind at flying heights, fog and line squalls; (d) the regular issue of general weather forecasts for use in the varied work of the Army; and, later, (e) the supply of information (at short intervals of time and quickly enough for it to be applicable at the time of its receipt by the gunners) of the wind and temperature at the different levels up to the vertices of the trajectories of shells fired from guns and howitzers. An account of this last function, one of the most important parts of the work of the section, has been given in an article in the Army Quarterly for October 1943. It introduced into practice the "equivalent constant wind" and "equivalent temperature".
Almost simultaneously with the establishment of the Meteorological Field Service, the Gas Adviser in France, Lt-Col. C. E. Foulkes, arranged for one Meteorological Officer, commissioned R.E., to be included in the establishment of each of the two "Special Companies" which were being formed for offensive gas operations. It appeared to me essential to have a single meteorological service under one control. I discussed this with the Gas Adviser who agreed and the two officers joined the staff at St. Omer (G.H.Q.) and assisted in the preparations for the first gas attack.
The basic meteorological information which furnished our "stock-in-trade" consisted of 5 telegrams daily from London, giving forecasts and coded reports in five-figure groups, 20 groups at 2 a.m., 100 groups at 9.30 a.m. and 80 groups at 7.30 p.m. It was at once apparent that meteorological observers were required to make observations in the British Army area, especially near the front about 50 miles from north to south but in process of extension to about double that distance. None of the staff of the Office could be spared, but four men of meteorological experience already in the Army were transferred, namely J. Durward (of the 4th Gordon Highlanders, the first to report on June 16 and for some time our only assistant), R. Pyser, L. G. H. Lee, and F. J. Parsons. Capt. C. J. P. Cave, who had been commissioned as the reserve Officer, came out on July 7, and undertook the instruction and posting of the local observers of whom 12 were obtained from the Artists Rifles.
The Meteorological Service grew naturally as the Army gradually realized its value. After the battles of Loos and Hulluch in September and October 1915, the Service, which then had no recognized place in the general Army organization, was formally established as "The Meteorological Section of the Royal Engineers" with a Commandant (Major), Captain, 6 Subalterns, 2 Sergeants, 16 Corporals, 1 clerk and 6 batmen; a car for the Commandant, 3 motor cycles for the subalterns and 2 bicycles for the observers not located close to their observation posts. From time to time this establishment was increased; in 1918 it was 16 Officers and 82 other ranks, with 5 Officers and 20 other ranks attached from Sound Ranging solely for meteorological duties. A further increase to 28 Officers and 187 other ranks was agreed by the Army later in 1918.
The Service began as a purely G.H.Q. establishment, but already by the end of 1915 it had been agreed that there should be a Meteorological Officer at each of the, then three, armies. These started in 1915 as Lieutenants, under a later establishment they became Captains, and provision was made in the final establishment for them to be Majors but the Armistice came and the promotion never took place. The Commandant was promoted Major at the end of 1915 and Lieutenant-Colonel in 1918. Sanction for the latter promotion, agreed by the Commander in Chief in France, was delayed by the War Office until the promotion of Maj. H. G. Lyons had been effected. It was largely due to this delay that the Officers did not get the promotion to Major which they had so long deserved. The section in France became, after March 31, 1919, the Meteorological Section of the British Army of the Rhine under the command of Maj. A. H. R. Goldie.
In December 1917 a detachment was sent to Italy where it remained until the beginning of 1919. It was initially under the command of Capt. A. H. R. Goldie, who wrote "It is worthy of remark that after some initial difficulties the British part of the weather charts was usually completed first both in our own Office and in that of the Italian Aerological Section. It is also noteworthy that the Italian Aerological Section could receive the French data more quickly via the British Sections in France and Italy than direct from Paris or via the French Section in Italy. These facts impressed the Italian Section with a great respect for British meteorological organization and British telegraphy."
In 1918 a detachment from the Section, under the command of Capt. D. Brunt, went to the Independent Air Force, whose Headquarters were near Nancy, and there gave meteorological advice vital to their operations and greatly appreciated by Gen. Trenchard and his staff.
The use of meteorological information for the offensive use of gas in connection with the Battle of Loos in September and Hulluch in October 1915, when cylinders discharged from the trenches were used, and later for attacks in which "projectors" were used, is outlined in the article in the Army Quarterly for October 1943. The brilliant use, by Capt. Bispham and Capt. Lamb, of katabatic winds, which provoked the enemy's comment that the British used gas when the meteorological conditions didn't justify it, ought to be specially mentioned.
After the Battle of Loos in the winter of 1915-16 when it was expected that the enemy would make further gas attacks, meteorological observations were communicated direct to Divisions whenever the wind was from a quarter favourable for enemy gas attacks, to enable the gas alert to be instituted when it was necessary and only when it was necessary.
It was in connexion with the information required for the use of or defence against gas that the airmeter was introduced to measure the wind at about 4 or 5 ft. above ground level in an open situation. As a result of examining a number of airmeter observations in which the values of speed at 2-min. intervals and the values of direction at intervening 2-min. intervals over a period of about 20 min. were measured, Capt. Goldie discovered the relation v/V = sin ½ A where v is the range of values of speed, V is the mean speed, and A is the angle through which the direction varies.
The main information required by the R.F.C. was naturally forecasts of weather and cloud, including cloud height, and visibility. When night flying developed, the upper wind became of great importance. At that time, it was extremely difficult to get observations of upper wind at night and trials were made with electric lamps and with flares but they were not very successful. Sir Napier Shaw sent out some Chinese lanterns but the candles in them blew out when the balloon was released. In November 1916, Lt Bispham tried covering the top of the lantern with the thin metal lid of a cigarette tin and got an ascent to over 3,000 ft. The method proved very successful, and the balloons were watched to as great a height at night as in the day-time. The ingenuity of N.C.O's at the pilot-balloon stations soon enabled them to devise a lantern which could be made, and was made, at the stations.
In connexion with the observations by pilot balloons, the computations were originally done by slide-rule after the ascent had been completed, and the computations took nearly an hour after an ascent lasting half an hour. At the beginning of 1916, with the assistance of Lt Entwistle and Corp. Durward, the procedure was simplified, and instructions prepared which shortened the time for computation very substantially; and after observers had become accustomed to the new method, they were able to do the computations during the ascent of the balloon and complete it within 2 min. of the end of the ascent. This was of outstanding value not only in connexion with the information about upper wind required by the R.F.C. but probably, even more important, in accelerating the issue of information for the Artillery.
A kite balloon was also obtained for meteorological observations. It soon appeared that the observations of wind from the kite balloon were affected by the balloon itself, when the anemometer was placed in its usual position on a trapeze above the basket. These speeds were about 40 per cent, higher than those measured by an anemometer 20 ft. below the balloon and 60 per cent, higher than the speeds obtained by observation of free balloons.
The account of the meteorological arrangements for the Battle of Loos has been given in some detail in the Army Quarterly for October 1943. The same article contains a summary of the relevant meteorological facts for the other main battles of the war. The outstanding importance of the success of the forecasts prior to and for Loos was that they established a degree of confidence in the meteorological service which enabled the service to develop and secure a comparatively high degree of use of meteorological information during the war.
The recognition of the importance of visibility was slow in development. It was however emphasized in the preparation for the battle of Cambrai, but the strategic use of predictable natural fog was never adequately examined or applied.
Early in 1918 meteorological aeroplanes were allotted by the R.F.C. and initially were flown by Lt G. Marden and Lt E. H. Sessions. Later, in May 1918, Capt. C. K. M. Douglas became available for meteorological work, and he and Lt Sessions provided not only observations of temperature and humidity up to a height of about 14,000 ft. but also a very illuminating series of cloud photographs from aircraft. The upper air observations of temperature found their most regular application in the preparation of the reports for the Artillery. Naturally, they also proved useful as aids to forecasts. Perhaps the most notable example was at the beginning of the final offensive of the war in August 1918. Gen. Rawlinson, who was commanding the army which initiated the final series of attacks, consulted me about the weather and I was fortified in my assurance to him that appreciable rain was not to be expected, by the fact which I quoted to him "that the temperature in the upper air was high and the atmosphere therefore stable" (a reason to be used with discretion, in the light of the rest of the synoptic situation).
From the outset copies of the synoptic chart were prepared, at first in very limited numbers by hand, and distributed both at G.H.Q. and A.H.Q,. Later, on the instigation of Capt. Goldie, "clay copiers" were introduced which permitted the preparation of a complete local Daily Weather Report and a wider distribution, and a new departure, colouring red the isobars of pressure above normal.
It became clear during the war in France that the standard meteorological observations and the code for reporting them were quite inadequate to provide the basis for the preparation of the forecasts required in military operations. Consequently a new code was prepared and used for reports from the stations of "Meteor". It included in addition to the information in the standard code (a) visibility by one figure on a logical scale of distances, which is one of geo metrical and not of arithmetical progression, (b) the form and amount of low cloud and of medium or high cloud, (c) the relative humidity, (d) present weather by two figures, (e) past weather by two pairs of figures to permit of reporting a sequence, (/) rainfall twice daily, and (g) maximum day temperature and minimum night temperature.
The code was discussed at a meeting with French meteorologists in London in July 1918, and in the spring of 1919 it was included, substantially without change, in the International Convention for Air Navigation, with the concurrence of the United States meteorological representative at the Peace Conference. The code formed the basis of the codes subsequently adopted by the International Meteorological Organization and was used generally in the interwar years and during the Second World War. The only major change was in the reduction of the scale for past weather to a single-figure scale; this deprived meteorologists of information of substantial assistance.
Another development was the inclusion in the regular forecasts of the expected day and night temperatures. Not until after the lapse of 30 years was it possible to persuade the Meteorological Office to include this information in its regular forecasts.
It would be unpardonable to omit from this account a grateful acknowledgment of all that the Meteorological Office in London did to facilitate the work of the Section in France. First and foremost by the ready, regular and prompt despatch of the collective messages; then by the preparation and issue of numerous forms and blank charts, both general charts and special detailed contour charts of the Army area for plotting local observations; and for the provision of instruments both standard and novel such as the swinging plate anemometer and the accessories for the field use of the airmeter; and improved theodolites and balloons more in number than the sands of the sea.
This article has dealt mainly with the initiation by the Office of the Meteorological Service with the armies in France and the development there in the application of meteorology in the war by land and in the air. The work of the Office for the Navy and the development of the Naval Meteorological Service would require a separate article for a description at all adequate of it.
The same remark applies to the Meteorological Service with the Expedition to the Dardanelles and subsequently to Salonika. This was under the command of Capt. E. M. Wedderburn, who became the leading expert on the problem of the meteorological corrections to gunnery and the refinements necessary for the proper computation of the "equivalent constant wind".
Similarly only brief mention can be made of the detachment which went to north Russia in 1919, officered by Capt. W. H. Pick and Lt M. A. Giblett. Out of this came Pick's Professional Note on upper wind and the discovery that at Murmansk the wind in the first 2,000 ft. often backed continuously from the surface wind, when the latter was NE., contrary to the usual veering of the upper wind.