Fifty years ago ...

From WMO Bulletin 5 (3), July 1956

The picture on the cover   

One of the most important factors responsible for the recent rapid advances in the science of meteorology is undoubtedly the introduction of the radiosonde as a routine method for measuring the pressure, temperature and humidity of the free atmosphere. The importance of the pioneering results of the early manned balloons last century, followed by the kites, balloon meteographs and aircraft ascents in the first half of the 20^th century cannot be denied, but it was only when upper-air data became available in large numbers and from a wide network of radiosonde stations that meteorologists were able to test out and improve their theories of the atmospheric processes in three dimensions and to apply them in their day-to-day analyses and forecasts. 

Less than 30 years have elapsed since the first radiosonde ascent was made in 1927 by Idrac and Bureau but in the meantime more than 50 different designs of radiosonde have appeared, of which perhaps 15 are now in routine use. The impossibility of satisfactorily comparing the accuracy of these instruments in the laboratory, owing to the difficulty of simulating flight conditions, has made it very desirable to organize international comparisons in which the instruments are flown in a manner similar to the routine soundings. The most recent, and by the most important, of these comparisons was carried out at Payerne, Switzerland, under the auspices of WMO, from 23 May to 15 June 1956. The picture on the cover illustrates various aspects of this work. 

Executive Committee 

The eighth session of the Committee was held at the Palais des Nations, Geneva, from 17 to 30 April under the presidency of Mr A. Viaut. 

(In view of the widespread interest in the subject of the International Geophysical Year, the decisions of the Executive Committee were reported in a separate article.) 

Atomic energy 

It was clear that many of the new techniques employing radioactive substances could be usefully applied to meteorology, for example in devising improved instruments for measuring depth of snow and soil moisture and in serving as tracers for studying the movement of airmasses. WMO would be called upon to play a dual role, first to advise Members on the applications of these new techniques in meteorology and secondly to assist other international organizations in this field. 

The Committee also considered the question of the effect of atomic explosions on the weather. There was no reason to conclude that nuclear explosions had had any large-scale effect on the weather. 

Water resource development 

One aim should be to achieve coordination of hydrological and meteorological work in all Member countries and, in parallel with this, for WMO to provide similar coordination at the international level. It was realized that the Organization was handicapped by not having a hydrometeorological expert on the staff of the Secretariat and the Secretary-General was requested to see what could be done as an interim measure to remedy this deficiency pending a review of the whole question at the next session of Congress.

Networks 

One of the most vital questions in international meteorology was the improvement of the networks of meteorological reporting stations.  The Secretariat was preparing a series of regional charts showing the existing and recommended networks for surface and upper-air observations. The Executive Committee recognized the usefulness of these charts and laid down the broad lines for an expanded project, which provided for regular distribution of the charts to Members and for the institution of an amendment service. 

Aeronautical meteorology 

To overcome difficulties which had been experienced in the past, an improved procedure was adopted for dealing with recommendations arising from International Civil Aviation Organization (ICAO) Regional Air Navigation meetings which were referred to WMO for action in accordance with WMO/ICAO working arrangements. 

The President of Regional Association II (Asia) informed the Committee that the present situation with regard to in-flight reports from aircraft was not entirely satisfactory in his Region, Similar views were expressed by other members. These reports are of immediate use to Meteorological Services in meeting the requirements of aviation. 

Administrative and legal questions 

The Executive Committee had to deal with a number of legal questions, such as the rules of procedure for the Committee, possible revisions to the Convention and the implementation by Members of resolutions and recommendations. 

One of the major items was the permanent building for the Secretariat, which was still housed in temporary quarters. An offer had been made by the Untied Nations to construct a new wing to the Palais des Nations in Geneva to house both WMO and the International Telecommunication Union, and the Canton of Geneva had offered to erect either a special building for WMO or an extension to an existing building. The Executive Committee expressed preference for the Canton proposal to provide a separate building for WMO and directed the Secretary-General to continue negotiations with the Canton authorities and submit details of the final scheme to Members for approval. 

Financial questions 

The  Executive Committee expressed concern about the difficulties in carrying out an adequate programme with the present very limited funds. As the maximum expenditure for the period 1956-1959 had been laid down by Congress, there was little scope for varying the annual budgets from year to year. The budget adopted for 1957 is therefore very similar to the current budget, the total expenditure foreseen being US$ 425 013. 

Each year there was provision for financing meetings of one or two working groups, and it was anticipated that a larger number of groups might wish to meet.  The broad principle was that preference would be given to small groups which had to deal with urgent questions which could not be solved by correspondence. 

Congress had decided to establish an Operational and Technical Development Fund amounting to US$ 9 600. The Executive Committee decided to support two projects, namely the trial period for the International Geophysical Year and a radiosonde programme in Burma during the IGY. 

International Geophysical Year 1957-1958 

The meteorological problems to be investigated with the aid of the observations made during the IGY related to the large-scale physical dynamic and thermodynamic processes of the general circulation. It was therefore essential that all the Meteorological Services of the world should collaborate both in carrying out the observations and in helping to make the results readily available to research workers. 

One of the functions of WMO was to promote the establishment and maintenance of systems for the exchange of weather information. Hitherto, this work had been limited mainly to the very important exchange of data needed for the day-to-day operation of weather forecasting services. This exchange would be continued during the IGY but it was not considered to meet the needs of research workers who were not so much concerned with the speed in obtaining the data as in their accuracy and completeness. Many Meteorological Services published their meteorological observations in the form of daily, monthly and annual bulletins, but it was not always easy for an individual research worker to lay hands on copies of these publications and it was sometimes very difficult to obtain the data he required from those countries where no such publications exist. It should also be remembered that there was considerable variety in the layout and contents of these national publications which increased the difficulties for certain types of investigation. 

The Executive Committee adopted a proposal whereby an IGY Meteorological Data Centre would be established within the WMO Secretariat. Meteorological Services would be asked to supply their main IGY observations to this Centre on standard forms (this would lead to a uniform presentation of the data) and the forms would then be catalogued and reproduced on micro-opaque cards. 

There would be four standard forms, one for the surface synoptic observations from land stations, one for similar reports from ships, one for combined radiosonde and radiowind observations an the last for separate upper-wind observations. 

To keep the amount of data to be handled within reasonable proportions, the surface observations would be entered on the standard forms would be limited to those at the four main synoptic hours. The marine observations should include all the ships which normally supplied weather reports, but the land observations would only be requested from selected stations. The basis of this selection was to provide a sufficient grid of stations for the preparation of synoptic charts on a hemispherical scale. 

It had been estimated that a complete set of IGY meteorological data would require about 30 000 micro-opaque cards. Each card would contain about 50 standard forms and each form would contain up to 40 surface observations or four radiosonde observations. It could be seen that the IGY Meteorological Data Centre would have to handle material amounting to many millions of observations. 

The total const involved in running the Centre was estimated to be of the order of US$ 300 000. 

The Executive Committee decided that a trial period should be organized from 6 to 10 January 1957. 

It was decided that, as far as meteorological codes and station index numbers were concerned, the Antarctic would be treated as a separate WMO Region for the IGY. The Committee also agreed that degrees Celsius and metric units should be used for all meteorological reports from the Antarctic; this would be yet another step forward towards the achievement of uniformity in meteorological units, which had so long been one of the most desirable but most elusive goals of international meteorology. 

Regional Association VI (Europe)—second session 

The second session of RA VI was held in March 1956 in Dubrovnik, Yugoslavia. 

Observations 

The Association was in favour of adopting the main synoptic hours (0000, 0600, 1200 and 1800 GMT) for these observations which were currently being made at the intermediate synoptic hours (0300, 0900, 1500 and 2100 GMT). By deciding that all countries in the European Region should release the balloon carrying the instruments exactly one hour before the hours of observation, the session took a new step towards the standardization of upper-air observations. 

The network of stations making surface or upper-air observations was examined in detail. For surface observations, a small addition to the stations existing in the Region on 1 March 1956 was considered necessary to obtain satisfactory coverage. 

Codes 

Consideration was given to the introduction of a special new code (EXFOR) for the exchange of temperature forecasts and to the adoption of 150 and 100 mb as standard levels for upper-air observations in the Region. 

Transmissions 

Important outcomes 

•        A plan for radio-teletype broadcasts to replace the present Morse telegraphy transmissions 

•        A reorganization of the broadcast schedule of North Atlantic Ocean weather stations operated by European countries. This reorganization provides for the successive transmission by the five stations of their surface observations with a delay of only two to eight minutes after the hour of observations, their pilot-balloon observations within 10 to 30 minutes and their radiosonde observations within 25 minutes to one hour. 

•        The development of experimental facsimile broadcasts, the standardization of the apparatus and the characteristics of the broadcasts. 

•        A general review, which could be finalized during a joint meeting with the International Civil Aviation Organization, subject to their approval, of all European meteorological broadcasts. In proposing this study, the Association stressed that the present system for the exchange meteorological data within the Region by Morse telegraphy and the international network of teleprinters allocated to meteorology was still insufficient to meet the needs for meteorological information.

•         Connection of the international meteorological teleprinter network of western Europe with the corresponding network of eastern Europe. 

IGY

The Association decided to carry out an investigation of the standardization of instruments and the methods of observations for hydrology and the preparation of climatological maps for hydrologists. The meeting adopted a project for a comparative study of the forecasting techniques for high-level flights and suggested that a special meeting of experts be convened. 

Elections 

Dr A. Nyberg, Director of the Swedish Meteorological and Hydrological Institute, was elected president and Mr M. Perovic, Director of the Hydro-Meteorological Service of Yugoslavia, was elected vice-president. 

Comparisons of sferics systems 

A comparison between thunderstorms observed visually or aurally and those detected by different types of sferics equipment in use in France, Great Britain and Switzerland was carried out from 11 January to 11 February 1955. 

The first part of the report restated briefly the principles of the equipment used and gave details of the methods and times of observations for the period of the trials. A list of 13 European countries which had been asked to supply reports of thunderstorms observe was also included, together with a map showing the positions of the sferics stations employed for the comparison and the area from which visual or aural reports of thunderstorms had been received. 

Results 

The chief feature was the very small number of fixes reported by both France and Switzerland and by both Great Britain and Switzerland. This was attributed to the fact that thundery zones were generally more numerous over sea than over land in winter which meant that many occurred outside the maximum range of 800 km up to which accurate fixes could be obtained with the two Swiss stations.  The number of coincident fixes found by France and Great Britain was substantially higher. 

As winter thunderstorm activity on the continent was generally weak and of short duration the report concluded that the cathode-ray direction-finding methods, in which readings are made for only 10 minutes for each observation, gives a poor chance of locating thunderstorms at this time of the year. It also concluded that the fact that the narrow-sector record did not record flashes outside the sensitive sector resulted statistically in a decrease in accuracy. Most of the thunderstorms occurring during the period of the comparisons were not detected by the Swiss network because they fell in the blind area. 

It was noted that the list of thunderstorms observed was incomplete. Some countries included only those reported by synoptic stations, which were too sparsely distributed to represent the true amount of activity. 

Japanese automatic rainfall stations 

Since 1952, the Central Meteorological Observatory of Japan had installed automatic weather stations for rainfall, consisting of 109 transmitting and 70 receiving stations. Their purpose was to obtain prompt and immediate information on rainfall in mountain regions were no observations could be effected otherwise. Heavy rainfall, especially when accompanied by typhoons, often caused destruction and disaster in Japan. The need for urgent flood warning was drastic. 

From spring until late autumn the transmitting stations furnished hourly UHF transmission of rainfall amounts (in mm) as Morse-cope signals. Every hour the receiving stations tuned their receivers and picked up the signals for onward transmission. 

The equipment consisted of seven units, i.e. the rain-receiving unit, the metering unit, the coding unit, the programme-clock unit, the transmitter unit, the power unit and the receiver unit. The first six units constituted the manned transmitting stations and the last unit was operated by an observer at the receiving station. Each unit was portable. 

The operating principle was simple and straightforward.  The rainfall was caught by a funnel 14.14 cm diameter with a wind shield, exposed on the roof of the transmitting station hut. The metering unit was a tipping-bucket system which incorporated a mercury switch. The instantaneous electric pulse, triggered by the mercury switch, corresponding to each bucket turnover (1 mm rainfall), energized an electromagnet in the coding unit and set the position of three Morse-code cylindrical templates. The templates could compose three numerals of rainfall amount from 000 to 999 mm, after which they returned to 000 mm again. A sliding key travelled along the templates, call-sign first, and interrupted the plate current of the transmitter unit. The plate voltage was stepped up by a motor-driven vibrator from a stack of air wet cells of the power unit, which also provided the electric power of the transmitting station. 

The time keeping and control of the whole programme was effected by the programme-clock unit. 

The receiving unit was a standard type receiver with ancillary equipment similar to that employed in the Japanese radiosonde system. The Morse-code signals are heard as audiofrequencies corresponding to the frequency of the vibrator. 

Because of their increasing reliability and ease of maintenance, the value of the instruments in the rainfall observation network of Japan was becoming fully recognized. 

Humid tropics research

Meeting of specialists, 22-24 March 1956 in Kandy, Ceylon, preceded by a symposium on tropical vegetation, in collaboration with UNESCO 

Increased knowledge of these climatic regions resulting from a carefully planned programme of research could appreciably assist the solution of problems affecting human settlement and economic development in the humid tropical zone.

The meeting considered that fundamental research in all scientific aspects was of the utmost importance and recommended the creation of a permanent committee to advise on all problems within the scope of the natural sciences in humid tropical zones. 

Considerable attention was paid by the meeting to the meteorological aspects of most of the problems dealt with and to the meteorology and climatology of the humid tropics. 

Authors of papers on tropical vegetation were urged to provide, for the area of study, mean monthly temperature, mean annual and monthly rainfall and mean monthly maximum and minimum air humidity. It was further recommended that a symposium should be organized to coordinate the aims and methodology of vegetation, climate and soil studies in the tropics. The symposium also proposed that Meteorological Services should be encouraged to keep records of temperature and atmospheric humidity and other data of interest to ecologists and that records should be started in regions which were insufficiently covered. 

It was felt that there was often a failure to make full use of existing meteorological data and that the special requirements for research were not always brought to the notice of the meteorologists who might be able to help them. 

No simple delineation could be made between the arid and humid tropical zones but it would be useful to draw a boundary between the two on a small-scale map. The possibility of dividing the humid tropical zone into subzones should also be studied. 

Suggested topics for inclusion in the UNESCO Humid Tropics Research Programme were: 

• Improvements in the observational programme, particularly for solar radiation, rainfall characteristics and evaporation 
  

• Dendrochronological studies to ascertain the climatic history of humid tropical regions 
  

• Study of the climate of the soil 
  

• Bioclimatological studies particularly human bioclimatology
  

• Jet-stream research on a worldwide scale with a view to improving tropical storm forecasts
  

• Establishment of observatories equipped with microseismic, sferics and radar instruments to help in forecasting cyclonic storms and thunder squalls 

Excellence awards to Australian selected ships 

A system of Excellence Awards to Australian weather reporting ships was instituted by the Bureau of Meteorology as a means of giving concrete recognition of the cooperation of ships’ captains and officers in the provision of daily weather reports on a voluntary non-allowance basis. This action was taken in pursuance of the resolution adopted at the 1955 Conference of Commonwealth meteorologists in London, recommending the practice of making awards to selected ships which consistently maintained a high standard in their weather observations and reports.

An Excellence Award would be limited to cases in which a high standard had been maintained in the performance of meteorological observations, the maintenance of a weather log and the transmission of regular reports over a minimum period of five years. 

Initiation of the award emphasized the importance placed by the Bureau of Meteorology on ships’ reports received not only from Australian waters but also from the Indian, Pacific and South Ocean areas and its desire to encourage ships’ captains and officers to report as regularly and accurately as possible. It was gratifying to note the increasing number of reports being received from selected ships. 

Reports were being received from 27 ships comprising the Australian reporting fleet, of which 16 were of Australian and 11 of overseas register. Since many of the ships of the Australian register were practically wholly engaged in the coastal trade, it was uneconomic to recruit and equip them as selected ships but every opportunity was taken to encourage all ships to report during storm and cyclone.  

Exploring Greenland 

In spite of the increased attention given to it by scientific expeditions in the 20^th century, Greenland remained one of the largest and least explored landmasses to challenge the resources of man. The long history of Greenland exploration which began a thousand years ago must have been uppermost in the minds of the scientists of eight countries who met at Grindelwald and the Jungfraujoch Research Station, Switzerland, from 3 to 8 April 1956 to plan the scientific programme and organization of a new expedition, the International Glaciological Expedition to Greenland (IGEG). 

Although it did not form part of the official programme arranged for the International Geophysical Year (IGY), the work of the expedition would be coordinated with the IGY programme. Investigations would be made in the sciences of meteorology, glaciology, geophysics and geodesy. Study groups would work both on the coasts and the ice-cap and the expedition was expected to be in the field from 1957 until 1960.  Two or three meteorological stations would be established to study especially the lower layers of the atmosphere up to about 300 m above the surface of the névé and the problem of snowdrift. 

Although the Viking, Eric the Red, had established settlements in Greenland before the end of the 10^th, little was known of the country before the English navigator Martin Frobisher landed there in 1578. The work of exploration which he initiated was continued by famous explorers such as Davis, Hudson and Baffin in the 17^th century and by Danish settlers at Godthaab in the following century.

During the 19^th century the mapping of the coastal areas was almost completed by Danish, English, American and German expeditions and a start was made on the exploration of the ice-cap which had hitherto prevented any attempt to reach the interior. This enormous ice-sheet, five times the area of France, covers the whole of Greenland apart from the coastal regions and constitutes the largest glacier in the  northern hemisphere. It rises to a general level of 3 000 m and is believed to have a depth of 2 000 m in central Greenland from which it flows slowly outward to the coats. If melted, the mass of water released would be sufficient to raise the level of the sea by more than 7 m throughout the world. 

The Danish explorer Jensen was the fist to make notable progress across the ice-cap when he reached a height of 1 700 m in 1878. In 1886, Peary and Maigaard reached a point 160 km inland, 2 300 m above sea level. Two years later, Nansen made the first complete crossing of the ice-cap from east to west. A second crossing was made by Peary and Atrup in the course of an expedition which determined the northern limit of the ice-cap. 

The founding of a station at Thule by K. Rasmussen in 1910 began an intensive period of exploration of northern Greenland by Denmark. Five expeditions under Rassummen and Koch used Thule as a base and Peary fitted out his polar expedition there. In later years it was to become an important link in a chain of Arctic weather stations. 

Further crossings of the ice-cap by the Swiss, A. de Quervain and by Koch and Wegener marked the progress of 20^th century Greenland exploration. By 1931 Germany had become the first country to make a crossing by air. In the same year, a British expedition under Gino Watkins made weather observations from the ice-cap beyond the Arctic Circle, whilst a German expedition led by Wegener wintered 300 miles further north. Since the Second World War, both French and British expeditions had established stations on the ice-cap itself.