


































HOM6_01_Bjerknes_Half_a_century


	
   History	
  of	
  Meteorology	
  6	
  (2014)	
   	
  1	
  
	
  

	
  

1	
  

	
  
	
  
	
  
	
  
	
  
	
  
	
  
	
  

Half a century of change in the “meteorological scene” 
 

J. Bjerknes 
University of California, Los Angeles 

 

Bulletin of the American Meteorological Society 45 (1964): 312–315. 
©American Meteorological Society.  Reprinted with permission. 

 

The "meteorological scene" at the beginning of our century had separate centers of 
activity, largely out of touch with each other. There was no world-wide communication 
system for weather data, and daily weather maps were of more local extent than today. 
The weather forecasting in each area was troubled by the lack of early information about 
travelling disturbances from the west. It did not help the European weather forecasters, 
for instance, that transatlantic cablegrams could bring a daily summary of the North 
American weather. That had been tried in the early years of the cable connection, but 
then again abandoned. The Atlantic gap had proved too wide to be bridged by 
interpolation on the weather maps, and radio messages from ships could not yet be 
contemplated.  

Upper-air observations were in their first stage of development and exerted no 
influence on the routine of daily forecasting. Manned balloon flights were a popular 
public spectacle; and the measurement of the close-to-moist-adiabatic rate of decrease of 
temperature with height was an important scientific by-product of such flights. 
Unmanned balloon flights with self-recording instruments had penetrated still higher than 
the manned ones, and had discovered the stratosphere.  

The people on the "scene of theoretical meteorology” were becoming aware of the 
interesting three-dimensional structure of the atmosphere, and began to look for tools 
from the science of hydrodynamics that could put weather forecasting on a scientific 
foundation. The old German genius of natural science, von Helmholtz, had already two 
decades before 1900 made the first important steps with his theorems of circulation of 
incompressible media; and my father, Vilhelm Bjerknes, had followed up at the turn of 
the century by extending Helmholtz' theorems to compressible media (like air) on a 
rotating planet. 



	
   Bjerknes,	
  Half	
  a	
  century	
  of	
  change	
   	
  2	
  
	
  

2	
  

My first childhood memories date from this period. The tapping of the typewriter 
in my father's study was heard year in and year out. But then also, during summer 
vacations in the country, a different activity took place. Impressive kites, far greater than 
the toy ones, were launched, carrying recording instruments. My role was of course only 
to watch while grow-up students operated the kites; and the purpose of the whole thing 
was far beyond my comprehension. As I later learned, the kite ascents were made to 
extend aerological knowledge northwards from Central Europe, where many balloon 
ascents had taken place, to the virtually unexplored Scandinavia. In technical terms, the 
ascents were made to count the isobaric-isosteric solenoids in a meridional profile. The 
new circulation theorems ca1led for such fieldwork, but I must add, as most of you know, 
that my father's tinkering with kite technology never caused the sensation on the 
meteorological scene as did the circulation theorem itself.  

I would like to mention a few other personalities on the “meteorological scene” in 
the first part of our century, and I hope you will excuse my bias in choosing these people 
all from Scandinavia, the only part of the world that I could observe at that time. 
V.W. Ekman 

One of my father's students developed theorems of his own, which have found 
their way to all standard textbooks and forever will continue to be useful. That was W.V. 
Ekman, an applied mathematician who invented what all the world still calls the "Ekman 
Spiral.” It is a symbol for the explanation given by Ekman of how friction at a boundary 
surface modifies the circulations derived by classical hydrodynamics for frictionless 
media. One of the most important applications of the Ekman Spiral is that of showing the 
mechanism of the maintenance of the ocean currents by wind drag at the ocean surface. 

Ekman later got his appointment as a professor at the small provincial Swedish 
university of Lund, and remained there for the rest of his life. From his "ivory tower" 
came a succession of fine research contributions, which built the theoretical structure 
from which modern oceanography got many of its present tools. As an example of the 
esteem of younger oceanographers for their lonely and modest senior colleague, I may 
mention that the young and dynamic worker, in oceanography as well as in meteorology, 
C.-G. Rossby, repeatedly confided to me that he had often, and very seriously, thought of 
abandoning all his empire building in America in order to go back to a small job under 
Ekman in the provincial university in the old country. 

Arctic explorers 
Then, let me mention a few arctic explorers. They also belong in a description of 

the meteorological scene. Some were scholars in their own right, and all of them went to 
their adventures more or less with the moral backing of the profession of meteorology, 
that wanted to see also the geographical frontiers of knowledge advanced. Before the turn 
of the century the Swedish explorer Otto Nordenskjöld had pioneered the navigation by 
ship from Europe to the Bering Strait north of Siberia; and the Norwegian Fridtjof 
Nansen had been the first to cross the Greenland icecap; and several years afterwards had 
his ruggedly constructed ship “Fram” cross the Arctic Ocean following the ice drift with 
the transarctic ocean current, whose existence he had postulated. These were glamorous 
world events in geographical exploration, and they had pushed the frontiers of 



	
   History	
  of	
  Meteorology	
  6	
  (2014)	
   	
  3	
  
	
  

	
  

3	
  

meteorological and oceanographic exploration further polewards. But more remained to 
be done! 

Quite naturally, the manned balloon came into the picture as the vehicle that could 
travel faster than the ship, bring more uncharted territory under observation, and also 
make a beginning in exploring the aerology of the Arctic. The Swedish balloonist S.A. 
Andrée and two young meteorologist companions pioneered that idea, and got the 
necessary financial support for a balloon flight from Spitzbergen at 80°N toward the pole 
and beyond. The risk of failure of such a flight was great, but not really forbidding. A 
balloon can stay aloft long provided it does not lose gas by the periodic thermal 
expansion and contraction between day and night. The Arctic summer does not have 
nights, and the balloon was expected to be able to fly there in almost constant 
temperature for a long time. Then also, the balloon would stay aloft long enough to be 
carried by the winds to some inhabited area outside the Arctic. 

Such was the plan, but it failed; and the balloon with its courageous crew did 
never return from the Arctic. 

It took thirty years for the mystery to be cleared up. An expedition of Norwegian 
geological surveyors in 1930 explored some uninhabited, and seldom visited, islands east 
of Spitzbergen,—islands that can only be reached by ship in summers of minimum 
volume of Arctic pack ice. There they found an old campsite with the remnants of the 
Andrée expedition. The diary and the meteorological log were found in good readable 
shape, so that the following thirty-year-old happenings could be reconstructed: 

All had gone well to begin with, and the balloon had travelled at low altitude 
about one-third the distance to the North Pole, when the wind dropped to a light breeze of 
variable direction. During that period the rope, that was being dragged behind the balloon 
to afford some amount or steering, got stuck around the corner of an ice hummock, 
whereafter the balloon remained helplessly moored to the ice. After a period of desperate 
waiting the balloonists had to release gas, and land. The tour back on foot across the 
rough ice and in a raft across open lanes, was a terrible struggle, and it ended at the 
uninhabited island from which no further southward push was possible. 

This was only one of the many tragic losses of young arctic explorers 
volunteering to take great personal risks in the service of science. I only mention the 
Andrée tragedy because it was very much part of my childhood scene. One of the 
balloonists was my father's student in Stockholm, Sweden. 

Today, as we all know, flying has conquered the Arctic. Regular long distance 
passenger flights connect Europe with Alaska and the Far East by way of the North Pole; 
and meteorological and oceanographic observing platforms with comfortable living 
quarters are maintained on drifting Arctic ice floes. The air freight logistics for such 
scientific activity is not entirely free of risk, but the risk factor is what we in modern 
thinking call "acceptable"; and, certainly, it is several orders of magnitude safer than the 
Andrée Arctic balloon flight. 

Space exploration 
Today the glamorous, and risky, frontier of exploration is space; and again young 

enthusiasts volunteer for it. "Space" is outside the atmosphere, and space science is not 



	
   Bjerknes,	
  Half	
  a	
  century	
  of	
  change	
   	
  4	
  
	
  

4	
  

meteorology. But we as meteorologists are not quite free of responsibility for the space 
billions this country is spending. I am referring to the disturbing fact that many public 
statements, delivered in favor of the immense appropriations for the conquest of space, 
offer the promise of what may look like commensurate future benefits to mankind to be 
delivered by the science of meteorology.  The statements seem to take for granted that 
large scale weather modification, made to order to enrich mankind, will automatically 
follow from the mastery of space.  I think it is our duty to society to tell that we as 
meteorologists do not believe in such dreams. 

Even the public statements which omit the weather modification angle, and only 
promise the more limited benefits from and improved space-supported weather 
forecasting, usually go too far.  A frequently heard theme is: when we get space 
platforms the problems of weather forecasting on earth will be trivial and easy to solve. 
Such promises should also be emphatically contested. Space platforms, even manned 
ones, we shall probably get in a not too distant future. But faultless weather forecasting 
will not follow. And meteorologists will then be blamed for not being able to perform the 
''trivial" job of turning the information from a space platform into perfect short and long-
range weather forecasts. 

Now, don't misunderstand me as being entirely anti-space. I am not. TIROS 
satellites were marvelous eye-openers for synoptic meteorologists myself included; and 
our world-monopoly on these wonderful gadgets is a source of world prestige of which 
we can be justifiably proud. But let us not lose our balanced view of what scientific 
weather forecasting really is: l) a quick compilation of data on the present state of the 
global atmosphere, and 2) a quick prediction of the change of that state by time-
integration of our dynamic equations. Ultraviolet, visual, and infrared observations from 
a space platform would help to some extent under heading (1), but hardly at all under 
heading (2). Even in the job of compiling the present three-dimensional state of the 
atmosphere I would not trade our reporting weather ships against satellites on a dollar for 
dollar basis. To reap the benefits from modern numerical forecasting we do need weather 
ships, and more of them, particularly in the Pacific Ocean. Satellites do not make weather 
ships superfluous. 

What should we recommend our bright young students to do with their careers on 
the present "meteorological scene"? I would exclude the glamorous trip to the Moon, and 
even that to Mars. Our meteorology on Earth is infinitely more important for mankind, 
and we need all the bright young people right here. There is plenty of choice of subjects. 
On the meteorological scene of today we are "teaching more and more about less and 
less''; meaning that more and more fields of narrow specialization, too numerous to be 
mentioned here, are available for choice. Modern society calls for all that differentiation, 
and I hesitantly admit that most of that diversification is inevitable. 

Weather forecasting 
But yet I would give highest recommendation to the less narrow and more basic 

field of meteorology, which was the concern of the founders of our science, and which 
still is our first duty to society: weather forecasting. All too frequently, students, and 
professors too, shy away from the subject of weather forecasting and go into one of the 



	
   History	
  of	
  Meteorology	
  6	
  (2014)	
   	
  5	
  
	
  

	
  

5	
  

nice little research specialties which are less nerve racking, and which do not force you to 
show the public how often you are wrong. 

But, fortunately, the weather forecaster will soon be better off. Electronic 
automation has already relieved him of much of the overwhelming load of data handling, 
and now also presents him with electronically computed forecast maps. True enough, 
these forecast maps are not infallible, because they apply strictly only to a "model 
atmosphere" which is a simplified version of the real atmosphere. But the computed 
forecast maps do have the great merit of being consistent with the teaching of the science 
of fluid media. And, with that sound foundation, improvements are bound to come to the 
still very young science of numerical weather forecasting. 

Oceanographic-meteorological research 
Since the AMS has given me this unique opportunity of addressing a large and 

representative professional audience, I cannot resist the temptation to wind up with a plug 
for the combined oceanographic-meteorological research, to which I am devoting my last 
active years.  It is quite logical to enter that field if you want to understand the changes of 
weather over longer range; in other words: the “climatic change.” 

The period of adequate marine observations for such studies extends about 80 
years. In the National Weather Record Center, in Asheville, N.C., 33 million ship 
observations are now stored, and the stockpile rapidly grows from year to year. 
Individual researchers of course cannot cope with the gigantic job of extracting all the 
useful information from that many millions of observations, and the science of ocean-
atmosphere interactions has therefore largely stagnated after a brief blossoming period in 
the early part of our century. But on the modern meteorological scene the fast electronic 
processing can salvage the stored treasures of information, and soon will do so, if the 
latest nationwide plans for the research on air-sea interaction get implemented. 

Fortunately, the past 80 years have also seen a good deal of measurable climatic 
change, so that much can be learned from a study of that important period. The 
geographical models of climatic anomalies found to apply for the recent past will also 
help us to evaluate the many different theories put forth for the more distant past, in 
particular those of the ice ages. 

H.U. Sverdrup 
We can enter this type of research armed with the knowledge contained in the 

theorems of circulation of atmosphere and ocean handed down to us from the primitive 
meteorological scene of half-a-century ago. But it is fitting and timely at this occasion 
also to remember how much was later added in the way of important tools for ocean-
atmosphere research by the late Harald Ulrik Sverdrup, whom we are honoring today. 

Dr. Sverdrup came from the same theoretical school as did his senior Swedish 
colleague in oceanography V.W. Ekman, but Sverdrup’s career unfolded more on the 
international plane, first as a Norwegian arctic explorer, then as a U.S. citizen in the 
directorship of the Scripps Institution of Oceanography, and finally back to international 
work in the old country. Among his many fine research contributions we here only 
mention one of his last, from 1947, which, by an ingenious combination of the circulation 
theorem and Ekman's theory of wind drift, gave us the simple rules for long-range 



	
   Bjerknes,	
  Half	
  a	
  century	
  of	
  change	
   	
  6	
  
	
  

6	
  

adjustment of' ocean currents dictated by primary meteorological change. The resulting, 
usually minor, adjustment in ocean currents has, in turn, a perceptible feedback effect on 
the atmospheric circulation, whereby the play of climatic change, in atmosphere and 
oceans, continues through decades, centuries, and millennia. 

It will obviously take a long time to get a firm hold on the theory of current 
climatic changes through verification testing by observations. But it seems to be a safe 
prediction that the AMS, when reviewing the state of knowledge on the processes of 
climatic change some time in the 21st century, will feel proud that in 1964 the name of 
Harald Ulrik Sverdrup was immortalized also by the institution of an AMS gold medal.  
 

 
Fig. 1.1. J. Bjerknes speaking at AMS in 1964 inaugurating the Sverdrup Gold Medal. 


