Fifty
years ago ...
From WMO
Bulletin 5 (1), January 1956
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To
meet a request from the International Telecommunications
Union, the WMO Secretariat has over the past three years
been collecting information from all over the world on the
number of thunderstorm days which have been observed. These
data have now been presented in a series of 17 world maps
giving the average number of thunderstorm days for each
month, for the quarters and for the whole year. |
The main article in the
January 1956 Bulletin concerned the International
Geophysical Year (IGY)
1957-58 (eight and a half pages). A report on the IGY had
been prepared by Prof. J. Van Mieghem, chairman of the WMO
Working Group on the International Geophysical Year. In view
of the importance of the programme and the wide interest it
had aroused, it was decided to reproduce the main sections
of the report in the Bulletin. Other articles covered activities of the technical
commissions, the Technical Assistance Programme, the second
world comparison of radiosondes, the World Climatic Atlas,
activities of the regional associations, increased efforts
to develop the arid lands, and artificial control of clouds
and hydrometeors.
International
Geophysical Year 1957-58
Meteorological
Programme
The organization of an IGY
is intended to increase our knowledge of the phenomena which
can be observed in the tropical zone and in the upper layers
at all latitudes. Meteorologists should direct their efforts
firstly to the systematic exploration, on a global scale, of
the upper troposphere and the stratosphere up to the maximum
bursting level of sounding balloons. There is therefore an
urgent need to fill the important gaps in the upper-air
network between the parallels of approximately 35°N and S
and to improve considerably the performance of vertical
soundings.
Programme
of investigations
Improvements in the
techniques of upper-air soundings, the increase in the
number of radiosonde stations n the extension of the
upper-air network make it possible at present to carry out a
daily three-dimensional analysis of the Earth’s atmosphere
over large areas up to a level of about 100 hPa. The
progressive development of the upper-air network has been
the main factor contributing to the substantial progress
made in meteorology during the last 10 years. Meteorologists
have become more familiar with the flow patterns associated
with various synoptic situations. Certain aspects of the
thermal and mechanical processes which maintain the general
circulation of the atmosphere have also been revealed, such
as the seasonal variations and the variations with height of
the momentum and energy exchanges between zones of different
latitudes. Nevertheless, many questions are still unsolved
and for many others only a very unsatisfactory solution
exits. The Special Committee for the International
Geophysical Year (CSAGI) therefore recommends that the IGY
investigations should be devoted to the large-scale
physical, dynamic and thermodynamic processes of the general
circulation ...
(There
followed a list of problems in synoptic and dynamic and
physical meteorology.)
Programme
of observations
… it should be pointed
out that the term observing station here means any station
carrying out synoptic observations of weather conditions.
These stations include land sations located in low country,
in the mountains, along the coasts and on islands, as well
as stations on board weather ships and selected ships.
To ensure that
observational data are as comparable as possible, CSAGI
recommends that the instruments used at stations which will
be carrying out observations during the IGY should be
checked without delay against national standards.
Standardization of records and methods of observation is
also desirable. Moreover, it is essential that WMO should
organize in good time, well before the beginning of the IGY
a worldwide comparison of the radiosondes in use.
(There
followed under “Synoptic and dynamic meteorology” a
description of surface and upper-air observations and, under
“Physical meteorology”, measurements of radiation,
atmospheric ozone, atmospheric electricity, radio
meteorology, composition of the air and precipitation and
exceptional phenomena (noctilucent and mother-of-pearl
clouds.)
Network
of observing stations
The history of
meteorological progress is inseparable from the history of
the successive developments in the observing network. In
spite of the considerable improvements which have been made
during the past 10 years, the network is still inadequate
because of the planetary nature of meteorological phenomena.
The main effort must therefore be directed towards extending
the network over the oceans and undeveloped areas.
(There
followed a description of the synoptic network, covering
vertical cross-sections, requirements of the IGY synoptic
network, gaps and deficiencies in the present synoptic
network.)
Action
to be taken
The need for upper-air data
is so great that any plans for the establishment of new
aerological stations in areas where the network is
inadequate should be warmly encouraged. Where extensive gaps
exist, it is better to increase the number of stations
rather than increase the number of launchings.
In view of the well-known
inadequacy of the aerological network over the oceans and
the importance of the oceans, where most disturbances
orignate, maximum advantage should be taken of all
possibilities offered by large or small islands for the
improvement of the aerological network.
Meteorological Services of
countries with whaling fleets should seek the cooperation of
the whaling companies in order that surface weather
observations may be made on board whaling ships during the
1957-58 whaling season and that meteorologists may accompany
some of those ships in order to carry out the aerological
soundings.
It is recommended that
automatic weather buoys be used in the southern seas where
no surface synoptic observations are available. These buoys
can transmit sea temperature, air temperature, pressure and
the wind close to the sea surface.
World
Climatic Atlas
Climatic maps are a means
of presenting a summary of knowledge of the climte of a
region in a form suitable for a wide variety of users,
including meteorologists, agriculturists, hydrologists,
civil engineers, biologists and those engaged in public
transport. In a reasonably sized atlas it is impossible to
present all the information required for specific purposes;
some users are interested in detailed maps for small areas,
others are satisfied with national maps and there is also a
growing demand for regional maps. For certain
investigations, world maps are required, as for example the
world thunderstorm maps.
At the second
session of Congress, the need for an up-to-date World
Climatic Atlas was recognized and it was felt that a certain
degree of uniformity in national and regional atlases was
desirable.
The
first task of the working group “set up to study these
questions] was to prepare specifications of requirements to
be met by national, subregional and regional climatic
atlases. It was realized that for purely national purposes
there is no imperative need to have national climatic maps
prepared to a uniform, internationally adopted
specification; such maps are however of use to neighbouring
countries and to international agencies and should therefore
be readily comparable with those of other countries and
capable of being joined to them to produce subregional and
regional maps. The specifications drawn up during the
meeting were designed to serve two purposes, namely to
provide guidance to meteorological services who are
preparing or revising climatic maps, and to ensure that maps
based on these specifications will provide reasonably
uniform material for subregional and regional atlases.
Points covered in the specifications are the map projection
and scales, indication of topography and relief, isolines,
layer tints, and the selection of stations. Details are
given for maps of precipitation, screen temperature,
humidity, atmospheric pressure, cloudiness and duration of
bright sunshine, water balance and radiation.
It was
recommended that Members of WMO should be urged to prepare
national maps and that regional associations should be asked
to consider ways and means for compiling the corresponding
regional sheets. For this purpose, diagrams showing how the
work can be divided up into separate sheets on scales of 1
to 5, 10 and 20 million are being prepared. The projection
recommended is such that, while distortion ofhte main land
areas is kept to a minimum, the sheets can be joined
together asrequreid for wall mounting.
Climatic
atlases should not be regarded as something static; however
good they may be, they must be subject to revision both in
the light of new data and of new ideas of physical and
dynamic climatology, The first maps to be produced should be
those which appear in orthodox climatic
atlases—precipitation, temperature, etc.—but the target
should be to produce maps of derived elements, for example
of the radiation and water balance. These maps are in one
sense the basic maps, for it is the radiation and water
balance which determine the temperature and most other
observed elements, than vice versa. Many users of climatic
maps have already found that maps of evapotranspiration,
water surplus, etc. are more suited to their needs than maps
of some of the more usual climatic elements.
Membership
The Kingdom of
Cambodia became the 92nd Member of WMO on 8
November 1955. The United Kingdom of Libya became the 93rd Member of WMO on 28 January 1956.
News
and notes
Dr H. Theodor Hesselberg
Dr
Th. Hesselberg retired from his post of Director of the
Norwegian Meteorological Service on 31 October 1955. During
his 40 years in this position, the staff increasedfrom 15 to
310, an indication of the rapid development of this science
and its many applications.
Dr
Hesselberg was the winner of the first IMO Prize in 1955.
Dr Ragnar Fjörtoft
Dr Hesselberg
was succeeded by Dr R. Fjörtoft. Dr Fjörtoft had been
Professor of theoretical meteorology at the University of
Copenhagen from 1952 to 1955. Prior to that he worked for 12
years in the Forecasting Division of the Norwegian
Meteorological Service and also spent 2.5 years in the USA,
mainly at the Institute for Advanced Study, Princeton. His
research was on theoretical meteorology, with special
attention to numerical weather forecasting.
WMO emblem
A design for
an emblem was submitted to all members of WMO for approval
in September 1955. As the necessary majority of Members were
in favour, it is now the official emblem of WMO.
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