Some radio reflections

Jotmrnn~ of Atmospheric

and Temsrriol

Pergamon

Physics,

Vol. 56, No. 7, pp, 807-813, 1994 Copyright Ca 1994 Elsevier Science Ltd Pnnted in Great Britain. All rights reserved @Xl-9169/94 $6.00 + 0.00

Some Radio Reflections G. M. BROWN Department

(Received infinal

of Physics,

University

of Wales, Aberystwyth,

U.K.

form25 November 1993; accepted 25 November 1993)

AbstractIt is a truism as valid in science as in any other activity that one career is frequently shaped by that of another. This was certainly the case with Sir Granville Beynon’s early career. In these reflections, the author recalls some of his personal and scientific associations with Sir Granville Beynon over 46 years which illustrate the same point.

shoulders of giants’. And who of us would not echo that thought? Half a gene~tion on, I am honoured to acknowledge my indebtedness to Granville for setting me off in my humble career, and to offer him my heartiest congratulations on the occasion of his eightieth birthday.

1. PROLOGUE

My title is not original: it was first used, I recall, as a catchy title to a talk by Sir Edward Appleton in the early sixties. To mention Appleton in the first sentence of these ‘reflections’ is appropriate, because it was through close associations between Appleton and the enthusiastic young Granville Beynon in his first job at the then Radio Division of the National Physical Laboratory (later the Radio Research Station) at Slough that the latter’s career was set. It was this link which laid the foundations for Sir Granville’s involvement in ionospheric research, and perhaps also it was partly through emulation of his early mentor, whom he was proud to have known at first hand, that he developed his unusual administrative ability. Maybe it was prophetic, after all, that on the very day (11 December 1924) that Appleton and his student Bamett first demonstrated the existence of a sky wave in radio propagation using the Boumemouth BBC transmitter (APPLETON and BARNETT, 1925 a,b) a new radio station opened at Swansea and Granville, as a ten year old boy, watched his father twiddling with the cat’s whisker of a crystal set of his own ~nst~ction as he struggled (successfully!) to receive the first transmissions over a four mile path. It is salutary to acknowledge the train which Even one of the surely moulds every career. world’s greatest scientists, Sir Isaac Newton, was able to say in a letter to Robert Hooke ‘If I have seen further than you, it is by standing on the

2. SOME

PERSONAL

MEMORIES

I first met Granville in 1947, one year after he had returned to his native Swansea following his employment at Slough. He was just beginning to set up some experimental radio research equipment at the University, and was looking for a helpmate. He had previously had an assistant called Brown at Slough, and it seemed natural for him to have another! The work appeared interesting to me also, and so began an association, a f~endship, and a partnership which continued at Aberystwyth when Granville moved there to the Chair of Physics in 1958. Looking back over these 46 years, it is interesting for me to see how Granville’s career developed, to have been a spectator in seeing how a gifted man ‘got to the top’, and to realize how the course of one life influences that of another. The authors of several contributions to this special issue could surely say the same thing. And looking back over the last 80 years, Granville has reason to feel grateful that it has been an extraordinarily interesting time to have lived through. Political, scientific, and technological advances have 857

808

G.M.BRowN

occurred at speeds that could not have been dreamt of when he was born. Yet, as today’s research workers spend so much of their time staring at VDUs and operating keyboards, as data flow in online from anywhere in the world from equipment that is often never seen, and as sophisticated analyses and displays can be carried out at the press of a few buttons, it is well to remember that much good work was done when none of these things was possible. In those early days at Swansea we had to do almost everything ourselves. I recall our building our own pulse transmitter (on a wooden frame!), and adapting some old Marconi commercial receivers which Granville had acquired cheaply for pulse reception. It was a luxury, which gave us many headaches too, when we acquired the first ionosonde, a clapped-out early Union Radio model which seemed like something very special (when it worked). The first paper in the first issue of this journal in 1950 was by Bartels, and was concerned with the detection of 27-day variations in F2 layer critical frequencies at Huancayo (BARTELS,1950). It was natural that this new journal, founded by Sir Edward Appleton and with Appleton as the first Editor-in-Chief, should be perused carefully, and as Granville and I had already started some work on E-layer parameters this paper turned our attention to 27-day recurrence tendencies in several geophysical parameters, including foE. So evolved work which led to much study of the fine structure of region-E, as well as the associated solar control, and the influence of the geomagnetic field. Granville was proud of his Brunsviga ‘calculating machine’ which Appleton had given him, and I suppose we counted ourselves fortunate to have this wholly mechanical aid to calculations. We slaved at it for many hours, pulling and pushing levers until our fingers were sore and turning the handle backwards and forwards. .Division was a particular demon to effect! It was a wonderful improvement when an electrically operated Marchant machine Our first joint (still mechanical) was acquired. paper was on 27-day recurrence tendencies in foE, and we ventured, perhaps naively at the time, into an early excursion into Sun-weather relations in reporting a sequence of 27-day variations in various atmospheric parameters, including foE and ground pressure, for a certain period. Use of the latter was, predictably, frowned some on by meteorologists, and one of these, who maybe enjoyed the opportunity the more because he was

an ex-research student of ours, had a slam at demolishing the significance of the correlation on statistical grounds. Granville was always in demand as a public lecturer, for he knew how to present material in an interesting way to non-specialist audiences. He was always dynamic and lively, with the great asset of an infectious sense of humour. He usually carried round some radio demonstrations to these lectures, and always liked to have someone with him - if only to drive his car, since driving for him was a chore which he was only too glad to pass to someone else if he could. This was not all that surprising considering the cars he ran! Granville has never been a showman in the automobile scene. Outside research, one of my first ‘big’ cooperative efforts with Granville was the planning, running, and subsequent publication of the proceedings of a three-day international symposium entitled ‘Solar Eclipses and the Ionosphere’ which was held at the Royal Society, London, in August 1955. This gave me an insight into his organising prowess, as well as his energy and drive which character&d all that he undertook. We decided to try to report most of the discussion which followed each presentation using another of Granville’s prized possessions, a massive reel-toreel tape recorder which weighed a metaphorical ton. Transcribing the recordings into script was difficult, to say the least, not only because the replay mechanism was incredibly clumsy to operate but also because the quality of recording was often poor. Sometimes we could only decipher part of a conversation; Granville’s solution was simple: ‘just make up the question if you know what the answer is’. The reverse was not so easy! One of Granville’s earliest involvements in international science, involvements which exploded in later years, was to serve as Secretary of a special committee formed under ICSU and spear-headed by URSI (when Appleton was President) entitled the ‘Mixed Commission on the Ionosphere’. He was always keen to point out that it was at the second meeting of the MCI, held in Brussels in 1950, that the first suggestion for organising the International Geophysical Year 1957-1958 was made. This was subsequently endorsed by the relevant International Scientific Unions, and URSI set up a special committee, with Appleton as Chairman and Beynon as Secretary, to plan the ionospheric programme. Subsequently, Granville was appointed ‘World Reporter for Ionosphere’ for the IGY. This was a major scientific enterprise,

809

Somemdioreflections and it was natural that I was drawn into it with him. We edited the various instruction manuals which were published for the ionosphere discipline, a task which was aggravated by the short time scale we had in order to publish the manuals before the experimental phase began. My only memory of this now is the long hours that we had to put in and the stamina which Granville exhibited. It paid off in one respect: the ionosphere manuals were actually the first volumes of the Annals of the International Geophysical Year to be published (although they were officially called Volume III in the very long series of volumes). As a special ionospheric input to planning the IGY programme, Appleton had the bright idea of publishing tables of hourly values of solar zenith angle (cos x) applicable to the 15th day of each month for every ionospheric station in the world then operating, to simplify data analysis of monthly mean ionospheric parameters involving solar control studies. There was some suspicion that these tables were really only required at the time by Appleton, because he was then much concerned with an analysis of temporal variations of foE, but it was agreed that they should be included along with other data in a detailed Manual of Ionospheric Srarions to be published by URSI. The production of this 586-page Manual was a pretty mammoth task which fell on us, but that is another story. Back to the cos x tables: each station was supposed to carry out its own calculations, but we soon realized that some uniformity in dealing with the variations of solar declination and the equation of time would be essential if such tables were to be of any use, and the upshot was that the burden of preparing these tables landed on B and B! At this time, electronic computers were just surfacing as practical tools, but there were only a few commercial machines in existence. We were really in the forefront of technology in having all these cos x tables produced (at considerable cost) commercially on a Ferranti computer, and I remember we were both very impressed. We were also greatly relieved that they did not have to be retyped - a computer printout was a new luxury! Granville was always keen to do things properly; in fact, he preferred a dose of extra icing on the cake if possible. To mark the beginning of the IGY, a Conversazione was held at the Royal Society in June 1957 and it was natural that the Swansea research group should be invited to contribute an exhibit. In the event, under

Granville’s guidance and the mechanical skills of several members of the group, a mode1 was gradually evolved which proved to be one of the stars of the show. In a contemporary account in Discovery it was singled out for special mention as ‘a beautiful model, among the outstanding exhibits’ (Discovery, 1957). Fig.1 shows the model, which may be better understood from the following quotation from the same article. ‘The model....consisted

of a series of white

bulbs encased in vertical incoming perspex

solar particles, (the

the Antarctic inlaid.

which

ionosphere)

phenomenon of aurora. in which

spirals

blue

of wire

produced lights

flashlight

representing in a case of

simulating

the

Below the perspex was a map of a number

of

compasses were

’

I recall how almost all other activity in the research group had to go into abeyance for several weeks while priority was given to perfecting this model. Another example of Granville’s ‘extra icing on the cake’ is provided by the way we hosted the MIST meeting when it first met in Aberystwyth in April 1976. [MIST stands for a series of discussion meetings on the Magnetosphere, Ionosphere, and Solar Terrestrial physics which are still held biannually in the U.K.] We just had to do better than previous meetings - so we laid on poster displays; exhibitions of books, manuscripts, and astronomical instruments; screened some NASA Skylab films; and put on a piano recital and an No wonder the account of the evening reception. meeting (KENDALL and RISHBETH, 1976) reported that ‘this most successful occasion...had several features new to MIST meetings’. And, as far as I know, several of these features have never been seen at subsequent MIST meetings either! These few personal reminiscences are, of course, highly selective, and they do not do justice to many other facets of Granville’s personality that have not been mentioned. After we moved to Aberystwyth our research interests diverged, although our close association in other areas grew even closer. It was a privilege to share with him the introduction of a postgraduate course on the physics of the upper atmosphere, which ran for over 20 years, and of a new undergraduate course on planetary and space physics which still continues to attract students. Fig.2 shows Granville in his garden at Aberystwyth (gardening was always one of his favourite ‘pastimes’) standing by an armillary

G. M. BROWN

810

sphere with the occasion Always a quick mind experienced

sundial which was presented to him on of his retirement in 1981. strong and vigorous chairman, with a and persuasive qualities, we who have him in action appreciate why he was

always in demand on committees. I from personal experience, that beneath a certain toughness there is a sensitive, kind nature which shows the true face

also know, a facade of tender, and of Granville

Beynon .

3. SOME scIENrIFrc

mv0LvEMENTs

I am sure that I hold the record of having been closely associated professionally with Granville Beynon for longer than anyone else. From what has been written above, it will be clear that my early research work was closely determined by this association, and it may be appropriate to expand briefly on some of this work and see how it led one worker to develop his independent interests and specialisations. This restriction clearly means that there is no intention of giving here a full picture of Granville’s overall scientific achievements. As already indicated, a large part of our earlier work together was concerned with detailed studies of the E region, its solar control over short period (27-day) and long period (solar cycle) variations, and the distortion of its vertical ionization profile This work arising from geomagnetic influences. led to the publication of seven ‘Beynon and Brown’ papers over the period 1950-1959. We stuck to the same order of authorship for each on a strictly alphabetical basis, in true Appleton style (who, for obvious reasons, was always a protagonist of alphabetical order!). For me, this early work was invaluable in introducing me to some important aspects essential for the proper treatment of geophysical data, e.g. conservation (or coherence) in data and how to deal with it in statistical significance tests, and ‘second order’ features like the equation of time and the annual variation of the solar distance which often had to be included. The biggest study was that of establishing, fairly unequivocally, the influence of the Sq current on the E region electron density profile through the vertical ionization drifts which arise when the current flows (East-West) across the (North-South) horizontal magnetic field. It reads a bit like a

detective story as the effect was gradually ‘nailed’ in a series of analyses of diurnal, seasonal, and latitudinal variations. It was this work which led me to become fascinated with geomagnetism per se, and was the seed which later took my interests more positively into this area rather than ionospheric physics. It is interesting to add that Appleton was also working along parallel research lines at this time (perhaps this should be put the other way round) and, as a result, there were frequent mail communications between him and Granville, as the latest work on ‘Sq’ was brought out on each side. Granville derived considerable enchantment from being at the receiving end of so many personal letters which always ended ‘Yours ever, EVA’. When we moved from Swansea to Aberystwyth my research work started to develop independently, although Granville, of course, maintained an interest in progress made. Initially, I further developed the studies of geomagnetic distortion of the E region, and 1963 saw the publication of our first paper with reversed authorship! It was at this time that the second international geophysical effort, the International Quiet Sun Years, was held, and Granville was much involved with this as President of the Special Organising Committee over the period 1962-1967. A special IQSY Office was set up in London under the able direction of Dr C.M.Minnis (who later became SecretaryGeneral of URSI) and voluminous correspondence ensued between Beynon and Minnis, who had been colleagues in early days at Slough, on all aspects of the IQSY programme. One of the useful things about working in the Physics Department at Aberystwyth at this period was the fact that each year we had three or four postgraduate students studying on our M.Sc. course on the physics of the atmosphere, and each one had to have a research project which could be completed within the year. This gave us the opportunity to ‘try out’ many investigations which might have been too risky as full three-year Ph.D. topics. One such project which I tried was to take advantage of our coastal situation to see if we could detect ocean tidal induction effects in Earth currents measured between suitable probes. The results were incredible: there, staring us in the face on the pen recordings, were beautifully clean lunar variations clearly linked to the tides in Cardigan I remember Granville remarking on the Bay.

Some radio reflections

Fig.1.

Model

simulating

the occurrence

of a magnetic

Swansea as an exhibit to mark the heginning

storm

and aurora

constructed

of the International

Geophysical

Year in 1957.

at

G. M. BROWN

812

Fig.2.

Sir Granville

Beynon with the armillary

Physics Department

sphere which was presented to him by the

at Aberyshvyth

on his retirement

in 1981.

813

Some radio reflections

contrast with the struggle which it had always been to extract any lunar tide from ionospheric variations. He spoke with some experience, having himself worked on lunar tides in the D region many years earlier. In our Earth current case, it was the solar tide which required extraction work to show it up! From my own student days at Cambridge I had nursed a real interest in the Sun and solar activity, which has always been with me, and there is no doubt that my early studies with Granville on the solar control of the E region appealed partly

because they pandered to these leanings. As indicated above, these studies also built up a great interest in geomagnetism, and as a result most of my subsequent research career was firmly set in these two areas. But here this story should end, because its continuation ceases to be relevant to the context of these radio reflections. What is relevant is to make the point that both these interests were fostered in those embryonic days when I had the privilege of initiating my career with Sir Granville Beynon .

REFERENCES APPLETON, E.V. and BARNEIT, M.A.F.

1925a

Local

reflection

atmosphere. APPLETON, E.V. and BARNFIT, M.A.F.

1925b

of wireless

On some direct evidence reflection

waves

from the upper

Nature 115, 333-334.

of electric

for downward atmospheric Proc.Roy.Soc., A109,

rays.

621-641. BARTELS, J.

1950

27day

variations

Huancayo. KENDALL, P.C. and RISHBETH,H. (eds.)

1976

in F2 layer critical frequencies

J.Atmos.Terr.Phys.,

MIST Meeting at Aberyshvyth.

1, 2-12. Q.J.Roy.Astron.Soc.,

17,457-471. Unsigned article

1957

The Opening of the IGY.

Discovery,

August, 321.

at