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Fifty years ago ...

From WMO Bulletin 6 (1), January 1957


Fifty years ago, the main items in the January Bulletin were climatology, technical assistance, radiation and radiosonde comparisons, the second session of the Commission for Maritime Meteorology, the International Radiation Conference, agrometeorology and the International Geophysical Year 1957-1958.


The picture on the cover   

The importance of meteorology in the technical assistance programmes in developing countries is increasingly being recognized. Meteorology ... is vital to the success of many other important technical assistance  missions. Without the basic meteorological data, the hydrologists, agriculturists, aviation authorities, transport officials and economic planners —to mention only a few—are unable to tackle their problems on a sound basis.  

It is gratifying to be able to report that a sum of US$ 288 000 has been made available for technical assistance projects under WMO in 1957: this figure contrasts favourably with the sum of US$ 22 950 provided in 1962, the first year of the WMO programme. There can be no doubt, however, that even the 1957 sum will not be sufficient to meet all the costs; it can equally be asserted that tall the basic needs for meteorological technical assistance have not yet been formulated in official requests from governments, without which a project cannot be undertaken. 

Priority in WMO technical assistance has always been given to building up meteorological services in countries where there is no service at all or only a very rudimentary service. A project of this kind is the mission to Afghanistan; the cover photograph shows Mr H.I. Anda, a WMO expert giving instruction to some Afghan trainees in Kabul.. 


The International Geophysical Year 1957-1958 

Instrument comparisons 

The Special Committee for the IGY (CSAGI) directed attention to the meteorological instruments to be used during the IGY and stressed the importance of obtaining the highest possible accuracy in the meteorological observations. It was recommended that the instruments used should be periodically intercompared in accordance with WMO specifications, that regional comparisons between the standard instruments of each country should be carried out and that CSAGI should obtain, through WMO, a list of the standard instruments in use in each country in the western hemisphere so that a programme for these comparisons and their coordination could be drawn up. Another resolution concerning the comparison of instruments invited the Radiation Commission of the International Association of Meteorology to designate two or three standard actinometric instruments from the 16 compared at Hamburg which could be used for the regional comparison of instruments not tested during the Hamburg trials of September 1955 and May 1956. 

Upper-air networks 

Several decisions were made which concerned the location of radiosonde and pilot-balloon stations. It was recommended that countries in South and Central America should establish and maintain pilot-balloon stations at high altitudes and that the observations effected at these stations should be made with two theodolites for the duration of the IGY. This resolution was complementary to one stressing the nee for information on the atmospheric circulation in equatorial regions. In view of the present inadequacy of the upper-air network in these regions it was urged that the equatorial countries of the western hemisphere should install a full network of radiosonde and radiowind stations for the period of the IGY. A third resolution asked the national committees of countries in the western hemisphere to consider the installation and operation of radiosonde stations adjacent to stations operating cubical meson telescopes. Whenever possible they should be within a radius of 25 km from the cosmic ray stations and should make not less than four and preferably six radiosonde flights per day throughout the IGY. Data for the pressure levels between 50 and 100 mb are particularly required.

Chemical content of the atmosphere 

The importance of measurements of carbon dioxide content of the atmosphere gave rise to two resolutions. One of these urged that measurements of atmospheric carbon dioxide be made whenever possible with the object of obtaining an accurate estimate of the total carbon dioxide content of the Earth’s atmosphere and the rate of interchange between atmosphere, oceans and soil. Measurements are especially needed over the oceans, at coastal stations away from the cities and at high altitude stations. Particular attention should be given to the carbon dioxide content of different air masses. CSAGI recommended that oceanographical stations in the western hemisphere should carry out the analysis of surface water samples for carbon dioxide content whenever and wherever possible by a standard procedure. These measurements could provide information on the exchange of carbon dioxide between sea-water and the atmosphere and its possible influence on the annual variation of the carbon dioxide content of the atmosphere. 

CSAGI also recommended that selected meteorological observing stations throughout  the western hemisphere should measure the chemical constituents of precipitation during the IGY. Detailed information on the methods used should be exchanged and duplicate samples should be analysed at different measurement centres to ensure that results were comparable. 

IGY world data centres 

At last three centres will be set up, one in the USA, one in the USSR and the third, consisting of a number of centres in different countries, to collect for particular branches of geophysics. 

Each centre will be a depository for the originals or copies of IGY records, observations and preliminary tabulations. A catalogue of all the material held by each centre will be made available to each national IGY committee and to responsible scientific bodies and investigators Each centre should be prepared to provide copies of the data in its charge at cost price. 

Each national IGY committee is under obligation to supply all its IGY data to at least one of the centres at its own cost and should inform CSAGI to which centre it will supply its data. 

The list of centres has not yet been fully formulated. WMO will continue to be the repository for meteorology and it is recognized that other centres must pay for copies of meteorological data required. 

Recovery of instruments 

As it will be essential to recover instruments launched during the IGY as rapidly as possible, the meeting recommended that suitable action should be organized at the international level. The WMO Executive Committee was asked to form a working group to prepare an appropriate standard international recovery label. To encourage the return of the instruments, a finder’s reward should be payable in local currency and this should be clearly indicated on the label. Appropriate arrangements should be made with the customs authorities of each participating country to facilitate the free transfer of the recovered instruments to their countries of origin. 

Nuclear radiation in the atmosphere 

The broad aspects of the use of radioactive tracers in the geophysical sciences has been discussed, mainly by a special working group. CSAGI recommended that during the IGY, measurements should be made on a worldwide scale of the nuclear radiation of the air and precipitation at the Earth’s surface and of solid particles deposited on that surface. National committees should combine their resources in order to facilitate the analysis of the collected samples. An interim committee has been set up under the chairmanship of Prof. W. Bleeker to consider the establishment of a network of stations and the standardization of sampling methods and simple analysis. 

Activities in the WMO Secretariat 

The IGY Meteorological Data Centre has now been set up in the WMO Secretariat with Dr G. London (Israel) as chief. The expenses of running the Centre will be recovered by charging for the microcards and other publications using as working capital the surplus from the first financial period. 

The first task of the Centre was to complete the arrangements for the IGY trial period (6-10 January 1957); supplies of standard forms for this purpose were despatched in good time to all concerned. 

IGY brochure 

… all the available information about the IGY meteorological programme has been gathered together and published as a printed volume. The main text of about 60 pages was written by Prof. J. Van Mieghem. This describes the historical development of the IGY and gives full details about the various aspects of the programme of interest to meteorologists. The remainder of the volume contains 14 annexes, dealing with such matters as standard forms, telecommunications questions, world days and recommendations for the competent international bodies on observations at sea and on radiosonde, radiation, ozone and atmospherics observations. 

The task ahead in climatology
By C.W. Thornthwaite 

It has seemed to me that never before has the development [in climatology] been so rapid as during these lest four years. 

Early history of climatology

Only after the period of rapid geographical exploration began was it shown that climates are not simple latitude belts. They proved instead to be highly irregular areas exhibiting contrasts in moisture supply and in wind movements as well as solar heat, which are reflections of the general circulation of the atmosphere and which, in turn, are strongly affected by the distribution, orientation and configuration of the great land masses and water bodies over the Earth’s surface. 

This new direction in climatology was given considerable impetus with the development of instruments and the collection of data. For the first time, regional differences in temperature, precipitation, wind and pressure could be given quantitative expression. But the thermometer and anemometer revealed large local differences in temperature and wind, vertically as well as horizontally. For climatological purposes, it was thought that these local variations should be avoided in some way, or at least generalized. Accordingly, early investigators devote much effort to developing standards of instrumentation and exposure. 

At the same time, the basic geographic quality of climatology was gradually lost from view. To many people at the present time, the content and scope of climatology is only this—the measuring , recording and averaging of standard meteorological elements. … climatology, when circumscribed in this way, is sterile and unrewarding. 

The fault lies, at least in part, with the climatologists who are responsible for the collection and compilation of the basic data. They have, too often, been satisfied to accept the old conventional approach, to continue the old techniques without reference to relevant developments in related fields. 

Extent of climatology 

Modern research in physical climatology show us that climates owe their individual characteristics to the nature of the exchange of momentum, heat and of moisture between the Earth’s surface and the atmosphere. The climate at a place represents the existing balance between incoming and outgoing fluxes of heat and moisture. 

Thus the proper field for study in climatology is not limited to the atmosphere alone but must include the land surface as well. … any region is a composite of innumerable local climates; the climate of the ravine, of the south-facing slope, of the hill top, of the meadow, of the corn field, of the woods, of the bare rocky ledge. Both the heat and moisture exchange vary from the ravine to the hill top and to the rocky ledge because of variation in the physical characteristics, position, exposure and aspect of these diverse surfaces. The colour, apparent density, heat capacity, moisture content and permeability of the soil. The characteristics of the vegetation cover, the albedo and roughness of the surface; these are all factors that influence the heat and moisture exchange and are thus important climatic factors. 

There followed three extensive, detailed sections on microclimatology, topoclimatology and field climatology. 

Related problems 

In studies of interrelationships of climate and oils, plants, animals and people and their clothing, houses and materials, we are still dealing with problems of the heat and moisture balance between the subject and its surroundings. We must consider a warm-blooded animal or man himself in the same way that we do a boulder, a macadam road, or a bush or tree. But in doing so, our problem is complicated by the fact that the body has need to maintain itself at some constant temperature and is at the same time producing heat which needs to be dissipated. Under varying conditions of climate the flux of heat may be to or away from the body Some animals possess physiological means for dissipating unwanted heat but others do not; these must seek out microclimates where the heat stress is tolerable. 

It is worthwhile at this point, however, to remind ourselves that climatology is a geophysical science rather than an aspect of biology. However much we may use the plant as an indicator or however vital we may consider the transpiration process, our concern is always ultimately with the exchanges of energy and moisture rather than the life processes of the plant. We must think of the vegetation cover as an agency in these physical exchanges. The physiological climatology of man and the warm-blooded animals may be approached in much the same way. Again, we are concerned with the moisture and heat exchanges. Here, the degree of biotic control is considerably greater but still the responses must accord with the laws of  thermodynamics. 

The principal problems in climatology relate to the heat and moisture balance and involve the measurements of the exchange of heat and moisture between the Earth’s surface and the atmosphere. However, … climatologists do not have a monopoly on the problems of heat and moisture exchange. Chemical and mechanical engineers are concerned with both in developing their industrial processes They must be considered in architectural design. Some of the most fruitful recent developments in architecture have been in climate control, using physical principles in making house interiors cooler and drier in summer and warmer and moister in winter. Actually, this vast field of technology is the concern of technical climatology. 

In recent years there have been numerous examples of the application of climatological principles in the solution of practical problems in agriculture, industry and defence. I regard this as a wholesome and thoroughly desirable development. However in order for our science to advance we must continually add to the store of basic climatological knowledge. Applied and fundamental research in climatology must go forward side by side. 

… four years ago I expressed the hope that climatology might soon be raised from its inferior position in the hierarchy of meteorology. This has come to pass to some degree; climatology has demonstrated its importance and is now far stronger in several meteorological services than formerly. For this progress we may be happy but not complacent. Only by diligent effort can we hold for climatology its newly won respect. 

Technical assistance and meteorology
By H. Treussart

The author made some general remarks about technical assistance in general and went on to say that he would be restricting himself not only to the subject of technical assistance and meteorology but to also to two missions he had carried out in Israel and Afghanistan. 

I think it is essential, at the very outset, to attempt to put meteorology in its true place among the various other forms of technical assistance and to endeavour to answer the simple question “Has meteorology the place it merits within the framework of technical assistance activity?” My answer to this question is in the negative. The abruptness of my reply may cause some surprise, but it is based on personal experience which has led me to conclude that it would be advisable not to put all technical assistance missions on the same footing but to introduce in particular the concept of key mission. 

If we examine the wide range of assistance missions, we see that a large number of them have quite significant repercussions on the progress of other missions, Similarly, some missions can only terminated after the completion of others with which they appear at first sight to be in no way related. As an illustration of this, I should like to mention the difficulty encountered in certain underdeveloped countries by all kinds of experts when endeavouring to recruit students at a level sufficiently high to ensure that their training will be profitable. This difficulty is usually an indication that the school and university systems are unsatisfactory and require revision. This means that there is a task for one or more educational experts, whose presence is essential not only to revise the school system but also, indirectly, to ensure the success of the entire technical assistance programme. This is a typical example of what I would call a key mission. 

… [during] the mission which I carried out in Afghanistan, we find that many experts require meteorological information in the course of their missions and recognize that if this is not forthcoming their mission loses a great part of its effectiveness. In support of this statement I should like to quote as concrete example the requests for rainfall information received from an irrigation expert, for evaporation data from a soil expert, for micrometeorological information from an expert of the World Health Organization responsible for the installation of drains in Kabul, for humidity data from a milk industry expert and for soil temperatures and wind data from an expert supervising the construction of runways. Unfortunately, in spite of the fact that a substantial technical assistance mission had been active in Afghanistan for several years, it was only possible to provide sparse and inadequate information, because a meteorological mission had only been in the field for a few months. 

Does this mean that all meteorological technical assistance missions are key missions? To answer yes would be to show a lack of objectivity. In actual fact, meteorological missions can also be classified. If we adhered to the official terminology, it would be possible to group them by simply indicating in each case the functions of the expert responsible. This would provide us with missions of instrument experts, observation experts, forecasting experts, etc. In practice, I think that a more general, but perhaps more valuable classification would be provided by distinguishing between development missions and organizational missions. 

Development missions 

My mission in Israel constituted a typical example of a development mission. The task was to set up an aerological service, including all that that entails—installation of equipment, training of a team of operators, preparation of a programme for maintenance of the equipment, etc. This, therefore, was essentially a technical mission with aims sufficiently well defined to permit unequivocal and more or less definite evaluation of the results. The director of the Meteorological Service was able to summarize these at the end of the mission by stating simply that a team of meteorologists in his Service had been able to carry out a radiowind sounding unaided, the results of which could be incorporated in the normal international broadcast. 

… this is the essential task of development missions; they are intended for well-established meteorological services which nevertheless suffer from a deficiency in a well-defined section of their activities, which they wish to remedy as soon as possible. They thus presuppose the existence of meteorologists capable of undergoing specialized training without difficulty. As the aims to be achieved are clearly defined, it is possible to assess quite accurately the time needed to complete the task. This was particularly true of the mission mentioned above; it was planned to last three months and at the end of that time the work was in fact finished. 

Organizational missions 

This does not hold good, however, in the case of an organizational mission. In this case, the problem is more complex, because factors are involved which unfortunately are not always of a purely meteorological nature. Such missions generally take the experts into countries where there is practically no Meteorological Service and sometimes even no meteorologist. They therefore have to make direct contact with the government officials and to induce them to take the decisions necessary for the establishment of the Service; these decisions may be delayed because they clash with the plans of certain other departments or even ministries. It is not possible, as in the previous case, for the Meteorological Service to prepare the way before the expert even arrives; the commencement of the work may therefore be slowed down owing to unforeseen administrative difficulties. 

WMO sent two experts to Afghanistan in 1955. At the moment of their arrival, the Meteorological Service was practically non-existent and they had first to overcome a certain number of non-meteorological difficulties—the salary problem, which could only be solved by reference to the salary scales obtaining in other branches and the problem of recruitment, which showed that staff requirements could not be met by a programme already established whereby students leaving the various schools would be employed. 

Another characteristic of these organization missions is that they cannot be dealt with simply by providing experts. As thy are required in countries where the Meteorological Service is far from adequate, there is a problem of equipment to be tackled, which the government is generally unable to solve completely, as it is unable with all the goodwill in the world to face the large-scale expenditure involved. It is frequently necessary, for this reason, to send not only experts, but also a large amount of equipment. Coming back to the case of Afghanistan, this material assistance took very varied forms. It was necessary first of all to provide meteorological instruments purchased in the USSR by the United Nations Technical Assistance Administration. Tools had then to be made available for the maintenance of these instruments and for training of a certain number of technicians. Finally, a vehicle was necessary so that the experts could construct a mobile workshop for the setting-up of the stations. 

An organization mission has in fact a variety of aspects, necessitating the use of all the means at the disposal of technical assistance; not only experts but instruments and perhaps even fellowships and scholarships may be required, since it is usually during missions of this type that the need for sending a certain number of students abroad to study is felt most strongly. 

Afghanistan – a key mission 

All these points are covered by the mission at present in Afghanistan but even this is not sufficient to ensure the development of the Royal Afghan Meteorological Institute with all the speed desirable. It would in fact be difficult to find a more striking example of a key mission. Aviation is at present awaiting weather data, agriculture is hoping for information and certain sections of the public health department find their activity limited by a lack of meteorological advice. The government is perfectly aware of the importance of the work to be done and for its part is making a considerable effort, which provides a magnificent example of international cooperation. In addition to technical assistance provided by WMO, there is now a programme of bilateral assistance between Indian and Afghanistan which has resulted in the opening of two observing stations at thee most important aerodromes of the country—Kabul and Kandahar. These stations are at present operated with Indian meteorologists who expect to be replaced by the Afghan observers being trained by means of WMO equipment and experts


Weather and potato blight in Chile 
By P.M. Austin Bourke, Irish Meteorological Service 

In 1845 the disease now known to be caused by the fungus Phytophthora infestans made its first appearance in the potato crops of Europe. It brought serious loss and distress to the farmers of England, France, Belgium, Germany and Poland. In Ireland, it led to disaster on a scale seldom paralleled. Out of a total population of eight million, a million people died as a direct consequence of the great famine caused by the potato crop failure and one and a half millions emigrated in the immediately following years. 

Today potato blight occurs in almost every region in which the potato is grown and although consequences as disastrous as those of the last century are now unthinkable, the disease continues to take a heavy toll of the crop in many years. 

The disease in Chile 

Chile has, in the past, been one of the few substantial potato-growing areas free of the scourge and it was not until late in 1950 that the appearance of blight there was confirmed. 

How the disease came to Chile cannot be determined for certain but it seems likely that it was introduced in diseased tubers, possibly in the form of rejects from the food stores of ships which had provisioned in Argentina or Peru, where the disease has had a foothold for a number of years. 

Once again, as in other countries, potato blight showed its ability to strike suddenly and destructively. In the year following its discovery, the disease was rampant throughout Chile and up to 50 per cent of the crop was destroyed. In the potato-growing island of Chiloé … some 3 000 of the island’s population were forced to emigrate. 

Counter measures 

Since no effective way to eradicate the disease is know, the Chilean authorities adopted the introduction of more resistant varieties of potato and the use of fungicides to hinder the spread of the disease. … The development, multiplication and commercial introduction of a resistant potato variety, which at the same time would combine good yielding and the desired culinary qualities, is of necessity a slow process. Meanwhile, the use of fungicides presents its own difficulties. Spraying is a costly business even in areas where labour is cheap, machinery for spraying is sparse and transport of equipment and materials is not easy in a country where the potato growing regions stretch for over a thousand miles of often difficult terrain. 

Aid from the meteorologists 

The life cycle of the fungus which causes potato blight is controlled to such an extent by environmental conditions that in the early days it was believed that weather itself caused the damage done by the disease. In certain humid conditions, the fungus forms spores outside the plant surface and it is at this stage that the disease is vulnerable to protective measures. Hence, the meteorologist can help considerably to make fungicide applications less costly and more effective by indicating to farmers the optimum times to spray—neither too late, when the damage is already done (since the fungicide has no curative effect) nor too early, when the protective layer on the plants is apt to be washed off by rains and a substantial amount of new unprotected foliage will have grown before the disease is again on the move. 

The main objective of the Chilean authorities in seeking meteorological advice in this problem was to lay the foundations for such an advisory service on fungicide applications. But there were other questions to which they also sought answers. To what extent had the lesser impact of blight in Chile in the years 1952-1956 been due to less favourable weather for the disease in those years compared to 1951, and to what extent to the partial introduction of resistant potato varieties and other similar measures? How often, climatically speaking, was blight likely to strike as severely as in 1951? What areas were suitable, by reason of high frequency of weather favourable to light, for the rigorous testing of field resistance of potato varieties? What areas, as an alternative to the humid and blight-prone south, would be used for seed potato production, as combing simultaneously weather conditions unfavourable both to blight and to the insect vectors which transmit virus diseases? 

Results in Chile 

It was possible to provide at least partial answers to these questions, which can be amplified and confirmed when more complete weather and disease observations are available. The criteria for use in Ireland for detecting and forecasting blight weather proved equally applicable in Chile, i.e. a minimum period of 12 hours with relative humidity not below 90 per cent and temperature not below 90 per cent and temperature not below 10°C, followed by at least four hours during which the foliage of the plants is wet owing to rain, drizzle, dew or wet fog. In the rainy area, these conditions are, as in Ireland, mostly associated with low pressure systems and often with the influx of maritime tropical air masses. In the coastal areas of north Chile where rainfall is sparse and where crops must be irrigated, the humid conditions favouring blight come from the frequent fogs which are caused by the cold coastal Humboldt current and which are often accompanied by morning drizzle, too light to make any measurable contribution to the recorded precipitation. 

The analysis of blight weather spells over the period 1950-1956 showed that these were in complete agreement with the outbreak of blight in late 1950, its epidemic spread and virulence in 1951, the damping out of the attack late in that year and the spasmodic revival of the disease in milder form in the later years. Weather as favourable to blight as that of 1951 is to be expected on an average of about one year in eight. In between the seasons of widespread epidemic blight, local conditions in almost every year will lead to losses of yield in sheltered and humid locations. Even in seasons of comparatively little disease on the foliage there is a risk of appreciable loss of crop due to washing down of the spores by rainfall to infect the tubers. 

Establishment of agrometeorological stations 

In order to provide data for a potato blight forecasting service, the Chilean authorities propose to set up a network of agrometeorological stations at their agricultural experimental farms. The observations will also be applied to investigations into the environmental aspects of other plant diseases of economic importance to Chile, such as wheat rusts, apple scab and sunflower rust. They will further be of value in planning and introduction of new crops and plant varieties, in determining the water requirements of crops as a prelude to scientifically planned irrigation and in the many other aspects of Chilean agriculture in which weather plays an important part. 

Future role of meteorology in Chile 

It was abundantly clear in Chile that it is not agriculture alone that feels the need for the application of modern meteorological methods. Many other interests in the nation’s expanding economy—forestry, fisheries, tourism, building, sanitation, medicine, aviation, hydroelectric work, water boards, etc.—stand to gain considerable benefit. There is a growing realization that the climate of Chile is as much a part of her natural wealth as are her copper mines and nitrate deposits, and could be far more efficiently utilized than at present in the drive to heighten living standards. There is, in fact, a bright and useful future for modern meteorology in Chile. 

Second session of the Commission for Maritime meteorology
Hamburg, 16-31 October 1956



Observations at sea 

… Voluntary observing ships, the number of which is of the order of 3 000, are classified by WMO as selected, supplementary and auxiliary ships. … A fly on the wall would therefore have been surprised to hear much talk of a hitherto unknown category of ship—the Crawford ships. The explanation of this mystery is that the Commission, following a proposal by Mr A. Crawford (Union of South Africa), devoted considerable effort to improving the network of observations in areas where merchant shipping is normally sparse. Bearing in mind especially the International Geophysical Year (IGY), the Commission considered that a concerted effort should be made to supplement the reports from selected and supplementary ships in areas from which few observations are received by obtaining the cooperation of other ships. Many such ships are only equipped with uncertified barometers and thermometers but reports from them might nevertheless be valuable. The Commission recommended that as many as possible of these ships should be recruited, that their instruments should be checked by port meteorological officers and that the ships be requested to report pressure and temperature at least for the duration of the IGY. An essential part of this scheme is that each such ships should be supplied with a simplified code-card facilitating the work of the observer. 

Another item, quite hotly debated, was the revision of the wind speed equivalents of the Beaufort numbers. Some delegations went so far as to suggest that the estimation of wind force on the Beaufort scale cold be replaced by measurements or estimations of wind speed in knowts of metres per second. The majority of the meeting did not share this view. It was noted that the equivalent speeds for the Beaufort numbers, provisionally adopted for international use in 1947 are not entirely satisfactory and in particular are not representative for estimates of the wind force at sea. Considering that the adoption of a more suitable set of wind speed equivalents is of basic importance for these observations the meeting recommended that these equivalents should be amended as suggested by the Netherlands. This recommendation, if adopted, will mean, for instance, that Beaufort number 8 will correspond to 32-36 knots instead of 34-40 knots and Beaufort number 10 will correspond to 43-48 knots instead of 48-55 knots. 

Another question studied by the Commission was the old problem of observing and reporting sea waves. It was concluded that waves could be more effectively observed and reported than at present. Instead of recommending a change in the existing codes to achieve his objective, the meeting agreed that it would be preferable to attempt to improve matters by issuing better and more precise instructions to observers in the use of the existing codes … 

Maritime applications of meteorology 

The problems of cargo ventilation had been studied by a working group and a draft of a “Note on cargo ventilation” … had been distributed before the session … the Commission agreed that a revised and amplified version of the paper should be approved by the president of CMM and submitted for publication as a WMO Technical Note. The Commission has thereby made an important contribution to the application of meteorology and to the carriage of goods by sea. 

Attention was also given to another large group of users of meteorological information—the fishermen. Every fisherman knows that accurate weather forecasts and climatological information are of vital importance to in planning his operations, in designing his gear, in dealing with storage problems and in ensuring his safety while at sea. The Commission considered, however, that the fishing fleets of the world are often not fully aware of the current possibilities of obtaining weather information; there is need for further extending the collaboration between WMO and the international fishery organizations and other agencies concerned, such as the Food and Agriculture Organization. A small working group was therefore set up to study and make recommendations on these questions. 


The Commission adopted in all 6 resolutions and 33 recommendations, only a few of which can be mentioned. A number of changes in the Technical Regulations relating to maritime meteorology were proposed and these will in due course be considered by the Executive Committee and Congress. At the closing session, the Commission established working groups on the following subject: technical problems, organizational and operational matters, marine climatology, and marine cloud album for use by observers at sea, sea ice.

H. Thomsen (Denmark) and K.T. McLeod (Canada) were unanimously elected president and vice-president, respectively. 


Radiation comparisons at Hamburg
By F. Möller, Secretary, Radiation Commission of the International Association of Meteorology

Measurements of the radiation balance of the Earth’s surface are mainly limited to the determination of the total insolation from sun and sky on a horizontal black surface, the so-called global radiation. Measurements or the recording of the second main part of the balance, the long-wave or terrestrial radiation, encounter great difficulties. For example, the oldest and best known instrument, Ångström’s pyrgeometer, permits measurements during calm weather only. The determination of the total radiation balance is, however, highly desirable. This is one of the sources of the energy balance and of the energy transports in the whole atmosphere, the evaluation of which on a large scale is the main task in the meteorological programme of the International Geophysical Year. 

During recent years, different devices have been developed independently in many countries for measuring the long-wave radiation only or for determining the balance of long-and short-wave radiation fluxes directed upwards and downwards. … it was recommended that systematic and critical comparisons between the different models of radiation balance meters should be undertaken in order to find out their properties and accuracy. 

… From 1 to 15 September 1955, a series of comparisons was carried out at the observatory of Hamburg-Fuhlsbüttel. On this occasion, ten different instruments re used and some designers of these instruments participated in the work. Because it was unfortunately not possible to include some of the known instruments, this procedure was repeated and a second series of intercomparisons was carried out from 15 to 30 May 1956, again in Hamburg. In this way some designers had the opportunity of correcting small defects found during the first meeting and of presenting the improved models for the second comparison. 

… [this] exchange of technical information between the designers of the radiation balance meters was an important complement to the primary purpose of the meeting, the comparison of the different instruments. 

The main object of the second meeting was to compare the devices for the measurement of the long-wave radiation; hence the pyranometers for measurement of the short-wave radiation fluxes upwards or downwards were not included. The instruments which measured long-wave radiation only or the long- and short-wave radiation together may be suitably classified according to the direction and the wave-length range of the measured radiation fluxes. Such a classification is particularly important for anybody who will have to make the choice of a suitable instrument. 

The 16 instruments were grouped into four types: radiation balance metres, infra-red balance meters, effective pyranometers and infra-red effective pyranometers.

Each group of instruments base on the same principle has its special advantages of disadvantages. In addition, special consideration should be given during a critical evaluation of different instruments to the purpose for which the instrument was designed: whether it was built for long-period records in all kinds of weather conditions, for determination of radiation sums during short periods, for exact instantaneous values of radiation, or finally for a sample measurement in different surroundings or on an expedition. An advantage for one application may represent a disadvantage for another, for example, the instruments for continuous recording may show a larger absolute error in the instantaneous value because such instruments have a larger inertia. 

Last but not least the question arises whether the instrument is commercially available or whether it is a single model, perhaps with excellent properties, which however, cannot be bought or is difficult to reproduce.


The Hamburg comparisons should only be considered as a beginning. On the basis of these comparisons and discussions, improvements will be made and indeed to the knowledge of the author have already been made. Therefore the less favourable opinions expressed about some instruments may already be obsolete.


International Radiation Conference
(Davos, Switzerland, 10-15 September 1956) 

… The conference was attended by a number of radiation experts from National Meteorological Services and from specialized research institutes. This large attendance reflected the increasing interest in radiation problems in general and the importance attached to recommendations regarding the radiation measurements to be made during the IGY. 

Discussions on many items led to conclusive results and to formal recommendations while in other cases they resulted in valuable contributions to our knowledge, especially as regards methods of observation and evaluation. It was thus possible to reach an agreement about different problems which had been discussed among radiation experts for decades without a final result and which now seemed ripe for solution. 

The most important recommendation is undoubtedly that dealing with the creation of a new pyrheliometric scale. Since two different scales for expressing measurements of solar radiation have been in use for a generation, the conference felt the urgent need to introduce a unique international scale, especially for IGY measurements and recommended the adoption of the International Pyrheliometric Scale 1956 before the start of the IGY and preferably by 1 January 1957. …. The conference was in a position to recommend that measurements made according to the original uncorrected Ångström scale should be increased by 1.5 per cent while measurements expressed in the Smithsonian scale (1913) should be reduced by 2 per cent. It is to be hoped that from the beginning of the IGY all radiation measurements in meteorology will be expressed in this new scale which has the two advantages of being uniform and of being nearer to the true value than the two traditional scales. 

Other long outstanding problems, such as the best aperture conditions for actinometers and the methods to be applied for the actinometric determination of atmospheric turbidity, were also the subject of recommendations. More recent problems discussed at the conference were the desirability of measurements of the different radiation components over the oceans and the free atmosphere, methods for measuring short-wave ultra-violet radiation, sky radiation, daylight illumination or the components of radiation balance ..

Practical instructions for radiation measurements and a terminology of actinometry are under preparation. A survey of the projects for radiation measurements during the IGY showed that while a large number of stations will be making observations, the distribution of the stations over the world is far from uniform. Finally, the conference had to discuss the possibilities of the technical applications of solar energy and the contribution to this problem which can be made by scientific research ...  


News and  notes

Presentation of IMO Prize to Dr Hesselberg 

The first IMO Prize was presented to Dr Th. Hesselberg, former director of the Norwegian Meteorological Institute, at Oslo on 21 September 1956. The presentation was made by the President of WMO, Mr André Viaut, at a ceremony in the meteorological institute at Blindern. Those present included a number of representatives of the Norwegian and other governments, Dr Alf Nyberg (president of Regional Association VI) and many university professors and meteorologists. 

In his tribute to the recipient of the award, Mr Viaut spoke of the three aspects of Dr Hesselberg’s work—developing his meteorological service, conducting important scientific research, and collaborating at the international level. He had actively participated in international meteorology since 1919 and the eminent position which WMO now held among the UN specialized agencies was to a large extent due to this “grand old man” of meteorology. Mr Viaut continued “if he had not been a meteorologist, he would have achieved fame in any other sphere of human activity to which fate might have directed him. He has the gift of combining courtesy, affability and the most acute sensitivity with an immensely idealistic faith and a firm refusal to compromise his principles.” 

Further tributes were paid by Dr A. Nyberg and by Dr R. Fjörtoft, the present director of the Norwegian Meteorological Institute. The latter was especially pleased that the first IMO Prize had been awarded to somebody from Norway, a country where meteorology is a science of great practical value. 

Dr Hesselberg was honoured again on 28 September 1956, when he was made an officer of the order of the Légion d’honneur by the French Government.


Membership of WMO 

The Sudan became a WMO Member State on 2 January 1957. WMO thus had 70 Member States and 25 Member Territories. 

Postage stamps in honour of WMO 

The United Nations would be issuing a set of 2 postage stamps in honour of WMO on 28 January 1957. The stamps would be for denominations of 3 and 8 US cents and would be of the same design except that the name of WMO would be in English on the 3c stamp and in French on the 8 c stamp. The stamps could be used for mail posted in the UN post office in New York. The stamps depicted a radiosonde balloon symbolizing the globe and the worldwide range of WMO’s activities.



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