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Fifty years ago …
WMO Bulletin 6 (2), April 1957
Apart from arid zone climatology, as mentioned above, other subjects covered by the April Bulletin 50 years ago were meteorological aspects of atomic energy, a progress report on observations made during the trial period of the International Geophysical Year 1957-58, climatic atlases, the Technical Assistance Programme and automatic weather stations, as well as reports of the International Geographical Congress and the second sessions of Regional Association I (Africa) and the Commission for Climatology.
An abridged selection of some of these articles is given below. Another will appear in the June 2007 edition of MeteoWorld.
Meteorological aspects of atomic energy
One of the most significant of all human activities in recent years has been the development of techniques for the utilization of atomic energy for peaceful purposes and it is well recognized on all sides that mankind is on the threshold of a new era in which scientific and technological advances in this field can, if rightly used, bring vast benefits to the whole world. The use of atomic reactor plants for the controlled generation of power is one of the most important and well-known of such benefits. The use of radioactive tracers for medical and agricultural purposes are also of great significance and almost equally well known. Many other less obvious examples could be given but it is quite impossible at the present stage to envisage the full scope of future developments and applications in this field.
To the meteorologist, the question naturally arises as to where does the science of meteorology stand in relation to these new activities. He asks himself what benefits can this new knowledge pass on to the science of meteorology itself and in what way can meteorology assist in the application of such knowledge in other fields. From the WMO point of view, the additional questions arise as to how can international collaboration in the meteorological aspects of atomic energy be fostered and in what directions should such collaboration be guided to ensure that the maximum benefit is rendered to the Members of the Organization. In this article some provisional indications are given as to the answers to these questions and in particular the activities of WMO are described against the general background of international collaboration ain the peaceful uses of atomic energy.
A small number of countries have for several years given attention to the meteorological aspects of atomic energy as part of their respective national activities in this field but a WMO policy on this question was first established by the WMO Executive committee at its eighth session in April 1956. The Secretary-General submitted to the committee at that session a document which reviewed the developments which had taken place in the international field. Such developments included the establishment by the United Nations of an advisory committee on atomic energy, from the recommendations of which had stemmed the conference on the peaceful uses of atomic energy held by the United Nations in Geneva in 1955. This conference … must be regarded as one of the landmarks in international cooperation in this field. Meteorology did not figure greatly in this conference.
The United Nations had also established a scientific committee on the effects of atomic radiation, what the function of advising on possible dangers resulting from the uses of atomic energy. There were indications that meteorological factors were involved in the work of this committee. The Administrative Committee on Coordination … had established a sub-committee on atomic energy with a view to ensuring coordination between the existing specialized agencies some of whom (e.g. WHO, FAO and UNESCO) were already engaged on projects relating to the application of atomic energy techniques to their respective spheres of activity.
But perhaps the most important development at that time was the decision to convene a conference of Members of the United Nations to discuss the statute of a proposed new international atomic energy agency.
Against this background of vigorous activity in the international sphere, the Executive Committee considered WMO’s future role in the meteorological aspects of atomic energy and adopted an important resolution which established that WMO “shall play its full part as a specialized agency of the Untied nations in advising appropriate international organizations and Members of WMO on the meteorological aspects of the peaceful uses of atomic energy”. The resolution also established a panel of four experts on atomic energy to study this question with a view to enduring that new techniques arising from this field of activity may be used to assist the science of meteorology in every possible way, including the development of new instruments and with a view to giving all help and assistance required by Members of WMO and other international organizations.
First meeting of panel
After an exchange of ideas by correspondence, the panel held a meeting in December 1956 … The panel drew attention to ways in which harmless radioactive tracers could be used to obtain valuable meteorological information and special reference was made to studies of atmospheric motions by the use of radioactive substances introduced artificially into the atmosphere. In this way air currents could be traced and atmospheric diffusion measured. The need for careful planning of any such experiments and in the selection of suitable tracers was stressed. In such experiments the meteorolgoists would clearly require the assistance of atomic physicists.
Another possible development referred to by the panel was the use of radioactive tracers in hydrology. Radioactive tritium could be used to mark molecules of water so that important applications to the hydrological cycle were possible. The possibilities of using radioactive tritium in association with water to study the formation of dew was also referred to. It was further noted by the panel that accurate estimation of the water equivalent of deep-lying snow could be obtained by the use of a radioactive source immediately beneath the snow in contact with the Earth’s surface. The water equivalent could be determined by measuring the attenuation of the radiation in a vertical path through the snow.
Other possible applications of radioactive techniques considered by the panel included the measurement of the water content of soil by neutron absorption and the use of natural radioactive substances produced by the action of cosmic rays on the upper atmosphere, to investigate such questions as vertical diffusion in the atmosphere, the removal rate of particulates and the increase of carbon dioxide in the atmosphere.
Location of stations
The panel noted that the measurement of atmospheric radioactivity was of particular importance not only for experiments for purely meteorological purposes such as have been mentioned above, but also for the work of other bodies such as the United Nations Scientific Committee on Atomic Radiation. It was pointed out that meteorological factors must be given due consideration in all techniques for such measurements. The panel accordingly laid down in some detail some principles which should govern the general arrangements for networks of stations at which such measurements would be made and the equipment to be used.
In these principles, the long experience of meteorologists in ensuring that instruments are suitably exposed was stressed. The fact that measurements of radioactivity of rainfall were utilized to obtain measurements of atmospheric radioactivity was noted and attention was drawn to the meteorologists’ knowledge of distribution of precipitation amounts, types and intensities. The advantage of using existing land meteorological stations as observing stations for radioactivity was pointed out and comments on measurements of radioactivity from aircraft and ships were given.…
The panel noted that in view of the fact that movement of radioactive substances released into the atmosphere by reactor plants either as effluents or through accidental causes would be dependent on meteorological conditions, the application of meteorology to the siting and operation of reactor plants was of importance. In this connexion, the panel felt that a technical note treating as fully as possible the meteorological problems which would arise in the different applications of the peaceful uses of atomic energy, would be of use to the Members of WMO ……
It will be seen that meteorologists and WMO have important roles to play in this new and important field of human activity It seem clear also that the science of meteorology will in due course benefit greatly by the application of techniques which until recently could hardly have been conceived.
International Geophysical Year 1957-58
Nearly six years have elapsed since WMO first announced its participation in the planning of what was then known as the Third Polar Year. …
Judging from the forms which are now arriving in the IGY Meteorological Data Centre containing the observations made during the IGY trial period, there is every reason to believe that the IGY will provide the research workers with a most valuable collection of meteorological data.
Arid zone climatology
By W. J. Gibbs
The Symposium on Arid Zone Climatology (with special reference to microclimatology) took place in Canberra, Australia, from 17 to 20 October 1956. The chairman was C.W. Thornthwaite, president of the WMO Commission for Climatology. Other delegates included Burgos, Eriksson, Fournier d’Albe, Ganji, Geiger, Naqvi and Ramdas [sic]. Observers included H.T. Ashton, W.J. Gibbs and C.H.B. Priestley.
In the introductory session the chairman did much to encourage an appropriate atmosphere for the symposium by a typically whimsical presentation of his important background paper on arid zone climatology.
The next session was concerned with evaporation and the water balance. [The papers by] Taylor on an automatic evaporation recorder, Philip on evaporation from soil and Hounam on pan coefficients were of particular interest. Discussion in this session was particularly animated. Evaporation pans, in spite of their deficiencies, were considered by many to be the best available instruments for the measurement of evaporation. There was some comment on the unsuitability of the month as a time unit in the preparation of climatic data. The need for the measurement of hydrolapse, surface temperature of lakes and pans and wind at the tope of the ground-disturbed layer and the desirability of consideration of these factors in studies of the water balance was stressed.
Radiation and the thermal balance were considered in the third session. The review paper by Drummond and that of Albrecht dealt with radiation problems; others, including that of Priestley, dealt with the transfer of heat from ground to air, whilst others were concerned with the thermal behaviour of soils. The type of radiation measurement required was discussed, including the need for a spherical collector in addition to a flat plate and for measurements within selected wavelength bands.
Sessions four and five dealt with the interrelationship of climatic elements and flora and fauna and contained much of interest to the meteorologist. The way in which rainfall, temperature and evaporation control plant and animal ecology was clearly indicated by numerous papers and particularly by that of Bodenheimer which dealt with weather effects on animals, birds and insects. The paper by Kraus explained some meteorological aspects of desert locust control. In these sessions there was a reiteration of much that has concerned WMO technical commission in the past—the unsuitability of the month as a unit of time, the fact that within a period of a few days or even a few hours plant life may suffer climatic crises and the non-representativeness of standard observations of particular micro-environments. The subject of dew also evoked much comment both in regard to its origin and its utilization by plants.
The review paper by Schmidt-Neilsen opened session six which was concerned with microclimate of man and domestic animals. Proprio-climate (the microclimate of the individual) was discussed, together with the function and properties of surface insulation (fur and clothing), surface colouring and other features. The importance of the measurement of ultra-violet radiation in studying its effects on animal and man was stressed.
In session seven on modification of microclimate, Fournier d’Albe presented a comprehensive background paper, reviewing the elements of microclimate and natural and artificial influences. This and the paper by Geiger on the modification of microclimate by vegetation were notable contributions to the session and the symposium Of interest were the references to the artificial stimulation of rainfall which indicated that we are still far from an answer to the question: “Is it possible to affect rainfall significantly?”
Session eight was devoted to a consideration of salting and chemistry of rainwater and Eriksson presented a thorough review of this subject, which is of considerable importance in arid zone work and of interest in many other fields.
Climatological observational requirements in arid zones were the subject of session nine. The general considerations were discussed in the paper by Gilead and Rosenan and particular reference to the problem of the measurement of dew was made in the paper by Masson. During this session the appreciation by WMO of the very broad scope of meteorological observations necessary was emphasized by reference to the WMO Technical Regulations. It was evident that there was a distinct need for these regulations to be put into effect in arid ones and also that cooperation between meteorologists and other workers in making integrated surveys was essential. Dew measurement was the subject of much comment, the defects of existing methods and in particular visual methods being pointed out. It appeared that the difficulties in this field were, in many respects, similar to those encountered in measuring evaporation. It was suggested that under some conditions much of the moisture condensed as dew comes from the soil.
Technical Assistance Programme
British East Africa
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