THE WEATHER
BY JAKOB BJERKENS
THE WEATHER
This part does not contain any scientific accounts of the
meteorological observations undertaken by the expedition in King’s Bay,
during the flight or during the twenty-four days’ stay in 87° 43′--this
will be left for the scientific journals to publish. I shall only give
here a characterization of the “polar-weather” as it was during 1925
and what was done in order to determine the best date for the start.
What kind of weather conditions must the flyers have for their journey
towards the Pole?
First of all there must be no fog at the place where they have to land.
Even if there is only a fog-belt extending a few meters above the
ground, a landing is impossible and a “forced-landing” would almost
certainly end in a catastrophe.
Further, the flyers must avoid passing through thick snow. The two
flying-machines might easily lose sight of each other, and if, in order
to keep in contact with each other, they should fly close together,
there is always the danger of a collision.
An overcast sky without rainfall is also useless. At least it must
clear now and again sufficiently to make it possible to navigate by
the sun. It is of course known that steering by the magnetic compass
is very uncertain so far north, as the extent of the deviations in the
Arctic is not sufficiently known.
Luckily so much is known about the weather in the polar ice region that
it is possible to choose in advance the most suitable time of year for
a polar flight. First of all, Nansen’s expedition by the “Fram” in
1893–1896 has given us this knowledge about the polar weather. During
almost the entire time of their drift across the Arctic observations
were made nearly every two hours in the course of the day, so that a
singularly rich stock of information exists. The observations have been
thoroughly gone through by the late Professor H. Mohn, so that we have
got them set out now in a most perspicuous form. Both the observers’
and Professor Mohn’s calculations are published in the work, “The
Norwegian North Polar Expedition XVII Meteorology.”
[Illustration: THE TWO METEOROLOGISTS]
[Illustration: N 25 ON THE WAY TO OSLO]
I am going to cite some figures from this book which give a clear reply
to the question, Which time of the year is the best for flying to the
Pole?
In the three years which the drift lasted the approximate number of
clear days per month were:
In January 14
„ February 12
„ March 9
„ April 8
„ May 7
„ June 0
„ July 0
„ August 0
„ September 0
„ October 4
„ November 11
„ December 15
Thus in midwinter (December and January) nearly half of each month is
composed of clear days, but the number quickly declines towards the
summer and there are none in the four months from June to September. It
happens, of course, that in the summer time the sun breaks through the
sky at some time of the day, but even _that_ is not very often. June
had on an average twenty-six overcast days, July twenty-seven, August
twenty-four, and September twenty-seven days.
[Illustration: ROUTE OF THE AMUNDSEN-ELLSWORTH FLIGHT]
As might be expected, downpours are much more frequent in the gray
summer months than in the other part of the year. The number of days
with rainfall were, on an average, as follows:
In January 11
„ February 11
„ March 13
„ April 13
„ May 20
„ June 20
„ July 21
„ August 19
„ September 22
„ October 14
„ November 9
„ December 9
Therefore one can count that two-thirds of all the days from May to
September have rain or snow-falls. In the winter time, on the other
hand, only one-third of the days have downpours.
Fog--the flyer’s worst enemy--also collects during the summer half of
the year. Foggy days on an average were:
In January 0
„ February 0
„ March 2
„ April 1
„ May 2
„ June 10
„ July 20
„ August 16
„ September 10
„ October 4
„ November 1
„ December 0
One is therefore pretty sure to be without fog until May, but from June
to September it is general. First, in October the fog begins to get
less and then disappears altogether in the middle of winter.
It appears quite clearly from the “Fram” observations that only the
dark period of the year has somewhat stable weather conditions, with a
clear sky. During the light period of the year the weather is gray and
thick.
These conditions are as unfavorable as possible for all flying
expeditions towards the Pole. The good weather during the
winter--October to March--cannot be taken advantage of on account of
the darkness, and it is necessary to be satisfied with the much more
unfavorable weather during the lighter period of the year.
Luckily there is, however, an intermediate condition of weather, when
the light is still there, but the summer’s gray weather has not yet
set in properly. April with its eight clear weather days, seventeen
days without downpours, and only one foggy day ought to offer the
best conditions for flying. Only one has to remember that when flying
over a longer distance the chances of getting into ugly weather are
much greater than one would imagine from the impression given by the
figures. In a distance of an extent equaling that from Spitzbergen to
the Pole, during a good month such as April, one will in most cases
have to pass through a bad and good weather-zone. In April, too, one
has to reckon with severe cold. “Fram” had a temperature as low as
-38° 4 c. in the month of April and even at the end of that month it
can go down to -29° c. If it is, therefore, one’s intention to fly on a
day of good weather, it is necessary to be well protected against the
severe cold.
In 1925 the polar flight could not be undertaken as early as April.
Notwithstanding the fact that the journey from Norway was undertaken
before the real opening of the shipping season, and that the
preparations in King’s Bay proceeded quickly and according to program,
our machines were not ready to start until the beginning of May. An
earlier start might well have been possible if the previous winter had
been spent in Spitzbergen.
It was the business of the meteorologists to determine which was the
best day in the month of May for the start. With “Fram’s” experiences
before us the prospects of finding a good starting day were not very
rosy. In May, 1896, when “Fram” was about halfway between Spitzbergen
and the Pole, there were twenty-five days with rainfall, and only three
days at the beginning of the month had clear weather. Should May, 1925,
turn out just as bad as May, 1896, the polar flight would take place
under very risky meteorological conditions.
What resources were now at our disposal to determine what kind of
weather was expected? First were the telegrams from the stations in
the neighborhood, indicating the kind of weather which was approaching.
This system is commonly used by all meteorological institutions which
have something to do with weather reports, and it was therefore
only natural that this should be made use of for the polar flight.
One can, however, know beforehand that to make weather forecasts at
Spitzbergen is much more difficult than at other places where it
has been tried before. For instance, Southern Europe is covered by
a network of telegraph stations which can report the approaching
weather. But in Spitzbergen it is not so easy. The network of European
stations certainly give reports of every condition approaching from
the south, but no telegraphic weather reports can be obtained from the
west, north, or east. There are, therefore, many situations where the
meteorologists, notwithstanding all the aid, can give no reply to the
question: “What will the weather be like to-morrow?”
And that is the case in Spitzbergen. But the polar flight had to be
undertaken from there, and had to extend more than 1,000 kilometers
above unknown regions in unknown weather conditions! How could any one
guarantee good weather for the whole distance?
I know that many meteorologists would reply to such a question that
this is beyond science. To prophesy what the weather will be like near
the Pole is pure guesswork. As now and again stress has been put upon
this view in the press, may I be permitted to defend the foolhardiness
I showed by venturing to tackle this problem? I admit that it is very
often quite impossible to say what the weather will be like on the way
from Spitzbergen to the Pole, and still less possible to predict how it
is likely to turn out in a day or two’s time. But meteorology allows
us to determine by indirect conclusions whether the prospects of good
weather are bright or whether the situation is too risky. That these
weather forecasts are based on very weak foundations, and therefore can
easily turn out wrong, was known by the airmen from the first hour.
Still they preferred to follow the advice science could give, even if
it was often vaguely formulated and given with all sorts of provisos.
The plan was not to risk a flight in any case through fog and thick
snow, where the aeroplanes would certainly lose sight of each other,
but to turn back if the weather should begin to look too threatening.
It would then be the meteorologists’ problem to find another occasion
when it would be again worth while to try and see whether in a renewed
attempt the way to the Pole would be clear.
For several years the exchange of meteorological weather reports had
been broadcast by wireless so that everybody who had a receiving
apparatus could make free use of the same. “Fram’s” receiving
apparatus was of the latest type and worked very well, even receiving
meteorological messages from countries very far distant. Mr. Devoid
attended to the receiving of nearly all the weather reports--a job he
was well acquainted with, through his position as assistant at the
Geophysical Institute at Tromsö. It can safely be said that we could
not have got a better man for the handling of all the radio weather
news which came to hand. He was untiring in trying to pick up and read
communications which were very weak, coming from far distant stations,
and it was, thanks to him, that the weather forecasting station
at King’s Bay was able to work with nearly the same full range of
meteorological observations as any southern weather forecasting station.
The meteorological despatches are broadcast by international
agreement and, with one single apparatus, one can receive accounts of
observations from the whole of Europe, North America and North Asia.
That has been made possible by the various countries all having come to
an agreement, in which they have arranged to send despatches following
each other closely according to a prearranged time-table. On the “Fram”
we regularly received the following despatches:
_Observations from eight o’clock in the morning_
A.M.
4:30 Stavanger (repetition of Annapolis U.S.A.)
7:00 London (English observations at 2 A.M.)
8:12 Tromsö (+ polar station Jan Mayen, Björnöya)
8:20 Königswusterhausen (Germany)
8:25 Haapsalu (Estland)
8:35 Lyngby (Denmark)
8:40 Karlsborg (Sweden)
8:50 Oslo (Norway)
9:00 London (England and Faroe Islands)
9:15 Grudziadz (Poland)
9:20 Paris (France, Switzerland, Belgium, Holland)
9:30 Sandhamn (Finland)
9:35 Budapest (Hungary)
9:40 London (ships’ observations)
9:50 London (collected messages)
10:00 Tromsö (collected messages)
10:15 Dietskoje Selo (Russia)
10:30 Vardo (North Russia)
10:40 Paris (collected messages)
11:45 Oslo (Norwegian observations 11 o’clock)
11:50 London (English observations 11 o’clock)
12:00 Dietskoje Selo (Russia and Siberia)
_Observations from two o’clock in the afternoon_
P.M.
2:12 Tromsö (+ polar station Jan Mayen, Björnöya)
2:20 Königswusterhausen (Germany)
2:35 Lyngby (Denmark)
2:40 Karlsborg (Sweden)
2:50 Oslo (Norway)
3:00 London (England and Faroe Islands)
3:15 Grudziadz (Poland)
3:20 Paris (France, Switzerland, Belgium, Holland)
3:30 Sandhamn (Finland)
3:50 London (collected messages)
4:00 Tromsö (collected messages)
5:00 Paris (collected messages)
5:45 Oslo (Norwegian observations 5 o’clock)
5:50 London (English observations 5 o’clock)
6:30 Stavanger (repetition of Annapolis, U.S.A.)
_Observations from seven o’clock_
P.M.
7:12 Tromsö (+ polar station Jan Mayen, Björnöya)
7:20 Königswusterhausen (Germany)
7:35 Lyngby (Denmark)
7:40 Karlsborg (Sweden)
7:50 Oslo (Norway)
8:00 London (England and Faroe Islands)
8:15 Grudziadz (Poland)
8:20 Paris (France, Switzerland, Belgium, Holland)
8:30 Sandhamn (Finland)
8:40 London (ships’ observations)
8:50 Tromsö (collected messages)
9:15 Haapsalu (Estland)
10:00 Paris (collected messages)
As will be observed Mr. Devold had a lengthy time-table each
day--Sunday as well as week day. The despatches which arrived during
the night and the early morning were received by the ship’s own
operators, who besides had, as part of their duty, to attend to the
expedition’s very large press correspondence when not attending to the
meteorological telegrams.
Nearly all the north, west and middle European states are represented
in the list. Observations from those countries, the despatch stations
of which one could not hear direct (for instance certain south and east
European), were received indirectly through the “collected messages”
from London and Paris, which give extracts of all the observations from
the whole of Europe.
Special mention should be given to the despatches which were sent
out specially for the expedition. First come the extra observations
which the U. S. A. started broadcasting from Alaska, Canada, and
the United States. These formed a very important addition to the
general meteorological observations which America usually sent out for
European use. It was especially important for us to get the complete
observations from Alaska--the nearest inhabited land--on the other
side of the Pole. The whole of this extensive observation material was
supplied gratis by the United States of America Weather Bureau, and
telegraphed free of charge by the U. S. A. Naval Station, Annapolis. It
gives me great pleasure to mention the tremendous assistance which the
United States gave us in this connection, and I herewith offer them the
expedition’s grateful thanks.
Despatches from Annapolis were received by the Stavanger station,
which repeated them to the “Fram.” This was also done free of charge.
The Norwegian telegraph authorities also showed their goodwill to the
expedition by instructing Vardeo Radio Station to receive despatches
from North Russian and North Siberian stations and repeat same to the
“Fram,” which hardly could have got them direct. I must also mention
the help the radio station in Green Harbour gave us by assisting in
receiving messages and forecasts during the critical days just before
the start.
The Geophysical Institute at Tromsö, which is the central station
for the weather-forecastings for North Norway, sent from its radio
station, three times daily, the Norwegian observation material.
The institute in Tromsö also deserves thanks for all the assistance
it has given to the expedition by sending out weather forecasts from
the moment the trip was planned, and whilst we made our preparations
in the winter 1924–5. It was a great help to be able to sometimes
consult the nearest meteorological neighbors in the south, who had many
years’ experience in the Arctic Sea’s meteorological readings. I will
specially mention a telegram we received from Director Krogness a few
days before the start which informed us that his analysis suggested
that a period of _stable_ weather conditions was now approaching. This
was of great assistance when the starting day had to be fixed.
When the whole apparatus was in working order we could receive
meteorological despatches from nearly all the stations. The network of
stations is closest in Europe, so close that we often saved work by
making a choice of stations. Asia and America have not such a close
net, but even here it is possible to draw a weather chart which is
largely correct.
[Illustration: THE COURSE OF THE SHIPS ON WATCH, “FRAM” AND “HOBBY,”
DURING THE COURSE OF THE EXPEDITION
The dotted area indicates the pack ice.]
Furthermore, in the English, French and Norwegian despatches there were
a certain number of observations from ships in the Atlantic, which in
themselves formed a bridge between the American and European stations.
The whole station system therefore formed an almost complete circle
round the polar regions, with the exception of Northeast Siberia, where
telegraphic communications are still bad, and this of course makes a
wide gap.
[Illustration: THE DOTTED AREA, ABOUT 12,000 SQUARE MILES, SHOWS THE
TERRITORY EXPLORED BY THE FLIGHT EXPEDITION]
The point now was (with the assistance of this net of stations round
the Arctic regions) to control an account of conditions moving inside
the polar area, and thereby draw conclusions as to what the weather
might be like along the flight route. With this in view the weather
chart for the whole region was drawn twice a day. Besides this, two
charts were prepared daily showing the reports of the European net of
stations, so that the weather conditions were being calculated every
six hours.
The drawing up of the weather charts took place in one of “Fram’s”
afterholds, which (with this end in view) had been prepared as a
“weather forecast salon.” There was not overmuch room for all the
charts, instruments and other apparatus which had to be kept there,
especially as the hold also served the purpose of an office for Dr.
Matheson, the expedition’s doctor. But with goodwill from both sides it
worked smoothly the whole time, combining the weather forecasting with
the doctor’s practice in the same room.
After the weather forecasting was properly established I often had the
pleasure of receiving visits from the members of the expedition who
were housed on land. During the quiet periods when nothing special was
being accomplished, our two journalists were frequent visitors. In lieu
of something better to do, they wrote about the weather, simply because
it is always possible to say something regarding this subject. As the
time for starting approached, Captain Amundsen and the other polar
flyers often visited me in order to see what the prospects were. During
the times that “Fram” was not lying in safe harborage Captain Hagerup
was constantly in communication with the weather-forecasting station
in order to ascertain in good time whether wind was approaching which
might drive the drift-ice towards us. On the whole I could not complain
about the amount of faith that was placed in the weather forecasts, but
it was often necessary to reduce this trust by reminding every one how
little we really knew.
All the outside observations were made by the meteorologist, Calwagen,
Manager of the Meteorological Observatory in Bergen. His duties were so
numerous that they deserve a whole chapter in this report, but as it
has so far been impossible to make any preparation of the observations,
Mr. Calwagen’s calculations must be reserved for later publication
in scientific journals. With Mr. Calwagen’s permission I shall only
mention here that part of his activity which was of direct use in the
weather forecasts.
In order that nothing which happened concerning the weather conditions
should pass us unnoticed, Mr. Calwagen made observations as far as
possible each hour of the day, continuing until late at night. These
observations included wind, sky, cloud movements, cloud structure,
cloud altitude, rainfall, atmospheric visibility, atmospheric
temperature and dampness, the readings of the barometer, etc. Further
we had brought with us a case of self-registering instruments for
measuring the atmospheric temperature and the dampness. Inside were two
barographs--one in the ship’s instruments’ compartment, and one in the
weather-forecast compartment, which both gave information about the
changes in the air pressure.
As often as we got rid of the low clouds, Mr. Calwagen sent up the
pilot balloons for observing the wind’s direction and strength. These
observations were of the greatest value for judging the weather
conditions, and I will therefore mention them in a few words here. The
observations took place as follows: A colored rubber balloon is filled
with water gas until it is one-half meter in diameter. One weighs its
buoyancy and thereby knows the speed with which it will rise into the
air. After the balloon has been sent up it is observed through glasses
which have graduated scales for calculating necessary horizontal and
vertical adjustments--this is called a theodolite. The theodolite’s
indications are read and noted each half minute whilst the balloon
rises. Afterwards it is possible to reconstruct the course which the
balloon has followed, and to ascertain hereby the course of the wind at
the different heights.
It was not always easy to find a suitable place to set up the
theodolite. On board the “Fram” it very often happened that the balloon
after some minutes got behind the ship’s masts or funnel, and thereby
was lost from view. On the ice in the fjord it was generally possible
to find a good spot with the exception of the days when there was a
heavy swell on the water outside, which also set the fjord ice making
slight undulating movements, and which were disturbing enough when it
was a question of reading one-tenth of a degree on the theodolite. Near
Danskeöen, where there was no useful fjord ice, Mr. Calwagen had to be
rowed ashore for each pilot observation in order to have firm ground
below the theodolite. Generally he chose the little islet “Likholmen,”
where he could sit and have an uninterrupted view on all sides. When
the “Fram” went out to get fresh water-ice from an iceberg which had
got aground, Mr. Calwagen was there immediately and set his apparatus
up on the iceberg. This is probably the first time that pilot balloon
observations have been made from an iceberg.
With the execution of all these pilot balloon observations, under
conditions which were continually changing and often difficult,* Mr.
Calwagen had to use all his care and all his skill. It can certainly
be said that he made use of every possibility imaginable in order to
collect data which might be helpful in supplementing the expedition’s
weather forecasts.
* After having sent in this report, the sad news had just been
received that Mr. Calwagen has been killed in a flying accident at
Kjeller, near Oslo, on the 10th of August, 1925. Immediately after
arriving home from Spitzbergen he commenced to work on that branch
which he was the first to start in Norway, namely, the reading
of the atmospheric conditions by self-registering instruments
installed in aeroplanes. In the course of the last year he has
personally taken part in many flights in order to complete the
registering-dials of the instruments from his own observations. The
accident happened during such a flight, just when he was engaged in
collecting observations for determining the atmospheric belts.
All who were with the expedition will no doubt remember Mr. Calwagen
as a practical man, helpful, impulsive, bubbling over with merriment,
capable but at the same time possessed of a modesty which was the
natural result of his noble altruistic nature. We all feel very grieved
at such a man’s death.
When it was necessary to have two men for the pilot balloon ascents,
Mr. Calwagen got excellent assistance from ice-pilot Ness, who,
according to what he himself said, was only too glad to be employed a
little on such an occupation during the long hours in which “Fram” lay
idle, not giving him enough to do.
Altogether sixty-two pilot balloons were sent up between the 15th
of April and the 29th of May. It was possible to follow one of them
through glasses to a height of 10,500 meters. This, however, was only
possible because there was very little wind all the way up. Generally
the wind was so strong that the balloon was lost sight of at a much
lower height.
It will lead us too far into scientific spheres to describe all the
methods used in determining the weather conditions from weather-charts
and from observations which were made. I shall have to content myself
by just mentioning the main principles which must be taken into
consideration when choosing the starting day.
It is the general experience that the regions which have low air
pressure mostly have cloudy weather and rainfall, whilst places with
high air pressure have fine weather with a clear sky. The point was
therefore to avoid conditions where a depression was moving towards the
Pole.
In order to be pretty safe from bad weather it was necessary to choose
a high pressure condition. Further, the high pressure would have to lie
north of Spitzbergen so that the aeroplanes should not fly out of good
weather directly into bad on the way north. A high pressure condition
over the Pole would necessarily bring with it northeasterly winds and
cold weather in Spitzbergen. This northeasterly wind would (at West
Spitzbergen) be an off-shore wind and therefore would signify clear
weather. Along the north coast of Spitzbergen the weather would be more
doubtful, with a northeast wind which would cause the air to rise up
against the hills and form clouds. But these cloud-masses on the north
coast would very often only stretch out over a limited area which the
flyers could pass in a short time, preferably by flying over the clouds.
One has the best guarantee for stable weather conditions when the
pilot balloons show that northeast winds are not only to be found on
the ground but also higher up. One knows then that the high pressure
condition around the Pole will reach high up in the atmosphere and is
not just a low formation which could be swept away by the first attack
of a storm center from elsewhere.
The first high pressure condition in May occurred on the 4th, just when
the aeroplanes were finished mounting. This favorable condition did
not last long. The low pressure over North Norway increased and passed
northeast (along the dotted line on the chart) by pushing the polar
high pressure aside towards Greenland. Before the final preparations
were finished on the 8th of May the low pressure had got so near the
Pole that it was not advisable to start.
A period of drizzly weather followed now when it was impossible to do
anything else but wait. The wind was mostly between west and south, and
the sky was overcast and we often had snow showers. Only now and again
it cleared for half a day, but never long enough that there could be
a question of starting. This state of affairs lasted until the 18th
of May, when a change took place. A heavy storm center, which passed
Björnöya, turned the wind easterly at Spitzbergen, and behind the bad
weather a high pressure region appeared which moved from Labrador via
Greenland towards the Pole. The wind was still too strong, and it was
not quite clear at Spitzbergen, but there were good prospects that the
next few days would bring good weather conditions for the flight. The
planes were therefore made ready to start at short notice.
We had still to wait three days before the weather was as it ought
to be. The high pressure region had spread itself long ago over the
Arctic Sea, and the bad weather which passed Björnöya had moved to
North Siberia, but right up to the morning of the 21st we had dull
weather with snow now and again in King’s Bay. The reason was a slight
local depression which had remained persistently over the warm current
which the Gulf Stream sends along the west coast of Spitzbergen. On the
21st there was, for the first time, sufficient easterly wind to drive
the snowy weather out to sea, so that from midday on we had radiant
sunshine and a cloudless sky.
At last the condition had arrived for which we had waited so long, the
first useful condition since the planes had been ready to start. It
_had_ to be used, especially as the season was getting on towards the
end of May and the danger of fog was increasing each day.
So far we had not seen any fog at Spitzbergen and if one had not had
the knowledge about polar fogs which “Fram’s” observations, 1893–6,
had given us, it would have been tempting enough to wait longer. It
was still pretty cold, -9° c. in King’s Bay on the 21st of May and at
the Pole one might risk calculating that the temperature would be down
to -15° c. Both for the planes and the crews it would have been better
and more comfortable to have had a more summery temperature. But of two
evils choose the lesser. As soon as the summer arrives in North Europe,
North Siberia, Alaska and North Canada, fog starts to reign over the
polar sea. Each air current above the Arctic, no matter from which
direction it comes, will bring with it warm air, which is exposed to a
lowering of the temperature on contact with the polar ice. This cooling
of the warm air which contains a great deal of dampness causes fog.
This formation takes place quite independently regardless of whether
there is high or low pressure. Even the best high pressure condition
in the summer, might therefore be useless for flying. During the high
pressure one will certainly be free from the clouds which produce snow
and rain, and the flight can take place in radiant sunshine, but fog,
even if it only reaches twenty meters up from the ground, will make a
landing impossible.
Fog of that kind was very unlikely on the 21st, in fact, one might say
the possibility of its existence was quite excluded. The northeast
wind on that day was so cold (-9° c.) that it must have come from the
very central regions of the polar ice, and it is hardly probable that
on its way to Spitzbergen it should have been exposed to the further
lowering of temperature, which would have been necessary to produce fog.
All these observations led to the following result: “Conditions to-day
are as favorable as can be expected so late in the summer. It was not
without nervousness that I advised the airmen of this result on the
morning of the 21st--never have I given a weather forecast with such a
heavy sense of responsibility. It was almost weighing me down with its
fateful importance, but on the other hand it was bracing to note how
the airmen arrived at their _much more responsible_ decision: “We start
to-day.”
And it was so! The last reports which were received at midday did
not show any change for the worse, so there was not the slightest
reason for calling off the start. The sky grew clearer continually;
Mr. Calwagen had the opportunity of following the ascension of a
pilot balloon with binoculars to a height of 4,000 meters. It showed
a northeasterly wind, apart from the lowest belt, where the wind blew
southeast from King’s Bay. The northeast wind high up had a speed of
between eighteen to twenty kilometers per hour. Therefore if this
strength should continue throughout the eight hours of the flight
towards the Pole, it would give the planes a deviation of 130–160
kilometers. So much petrol was to be kept in reserve that the last
stretch could also be flown, especially if one could reckon on the wind
being _with_ the planes throughout the flight homeward. Mr. Calwagen
wrote down the results of the pilot’s calculations and handed them over
to Captain Amundsen to assist him in the work of navigation.
Herewith the task of the meteorologists was ended, and in the last
unforgettable minutes we all stood as spectators, filled with
admiration for the six brave men who smilingly said good-by as if
they were just going on an everyday flying-trip. Not long afterwards
both machines were out of sight in the bright blue sky flying in the
direction of Cape Mitra.
* * * * *
Forty-five days later the polar flyers are home in Oslo again and
Captain Amundsen and Ellsworth’s meteorological notes are handed over
to us. We read them through with excitement. They contain news from
that part of the world which otherwise is out of the meteorologists
reach. They give him something to think about--especially after he has
dared to predict what kind of weather the polar flyers were likely to
meet in the unknown.
We start with the reports referring to the very beginning of the flight
from King’s Bay and see what the meteorological notes tell us.
After flying along the coast and passing the seven glaciers, the flyers
find Danskeöen’s and Amsterdamöen’s hills enveloped in fog which
continues northwards as far as the eye can see. What can this have been
caused by?
I cannot judge by personal examination because when twelve hours later
we ourselves arrived up at Danskeöen on board the “Fram” there was not
a sign of fog to be seen. But I am inclined to believe that the fog
has been composed of a layer of certain low-lying clouds, which had
often been seen by us at the beginning of May while we were lying in
Syd Gat waiting for suitable weather for the expedition’s start. These
clouds will often just form suddenly when a cold wind blows from the
polar ice towards the open sea. The moment the air arrives over the
first water-lanes or open sea it gets heated from below. The heated
layer rises above and whilst ascending forms clouds. Other colder
parts of the air then come into contact with the water, get heated and
rise also forming clouds, etc. According to the observations which we
had occasion to make at Danskeöen in the beginning of May, the lower
surface of these clouds is about 200 meters from the ground. Below this
there is generally a thick mist of fine snow which reduces atmospheric
visibility and will certainly be very disturbing for flying. Luckily
these clouds do not reach to any great height, seldom over 1,000
meters, so that one can easily fly above them. Besides, one can count
on their not forming further north than where one finds open water
channels of fairly large dimensions. It is therefore not _too_ risky to
undertake a flight above the cloud-belt towards clearer weather farther
north.
The polar flyers took this risk, and quite rightly too. After two
hours’ flight from Danskeöen going northwards there were no clouds, and
on the remainder of the flight there was nothing that obscured the view
over the polar ice.
The expedition has here made a meteorological reconnaissance of great
importance to all later flying explorations in the Arctic.
If a cold wind blows from the Pole one must reckon with the formation
of a low cloud belt over the wider water channels, even if it is
cloudless nearer the Pole. These clouds will form at all seasons of the
year, but perhaps mostly in the colder periods, when the difference in
temperature between ice and sea is greatest.
The landing took place in a light wind, therefore probably near to the
center of the high pressure region, which covers the Arctic Sea. On the
way into the high pressure region the wind, however, must have been
considerably stronger as is shown by the very considerable deviation
of 250 kilometers on an eight hours’ flight. In the middle period of
the flight it must therefore have been thirty kilometers per hour,
which is considerably more than the pilot observations over King’s Bay
had shown, namely, twenty kilometers per hour. The aeroplanes must
have flown, therefore, through a zone with strong northeasterly winds
blowing north of Spitzbergen, and then later come into calmer wind
conditions nearer the Pole.
This raises the question: Could one not have found a day with a gentler
wind blowing, when the deviation would have been less and the Pole
might have been reached? Probably the next day, 22nd of May, would
have been better as far as wind was concerned. Mr. Calwagen measured
the speed that day at Danskeöen, finding an east wind blowing three
kilometers per hour at a height of 500 meters. This wind would only
have brought a deviation of about 100 kilometers. But according to
Amundsen’s observation reports there was, on the same day, a little
northerly breeze at the landing place at 87° 43′, which means that a
contrary wind was also blowing on that day over the district nearest to
the Pole. And what was worse, on the 22nd May there was no longer clear
weather near the Pole.
The observations were as follows: During the last two hours of the
flight slight high clouds had begun to appear, but not so dense that
they could prevent the taking of solar observations immediately after
landing. The next day the clear weather was gone and solid gray cloud
layers covered the whole sky. It was the polar summer weather which had
started, just as we calculated it would from the “Fram” expedition’s
observations. And it did not improve during the following days; the
23rd, 24th and 25th were all gray-weather days, certainly without
rainfall, but also without sunshine. A northerly breeze was blowing on
the 22nd, 23rd and 24th, but it got calmer on the 25th.
The big high-pressure region which we had over the Arctic Sea on the
starting day continued, and the polar flyers must have been very near
the high pressure center as they now had calm weather. As far as
could be seen everything looked favorable, and whilst we were lying
and waiting at Danskeöen in radiant sunshine, the whole day long, I
personally thought that this good weather would certainly stretch right
up to the Pole. But here the expedition’s observations have taught us
something else, that in the best of weather conditions there is gray
weather at the Pole when the year is so far advanced as the end of
May. This is also one of the new meteorological results which this
expedition has brought to light--in regard to the “Fram’s” expedition
it happened that they did not meet any high pressure regions at the end
of May.
There were a few occasions when the clouds broke up at 87° 42′;
for instance, the 29th of May “dawned with sunshine from an almost
quite clear sky.” But this was only a sign that worse weather was
approaching. In the night, between the 28th and 29th, snow had passed
Spitzbergen on the way north. It reached the polar flyers on the
30th in their camp 87° 43′. The clearing on the 29th was therefore
just a passing phenomenon, and if the aeroplanes had started that
day southwards they would after a few hours’ flight have got right
into a heavy snowfall. These clearings, before the large wandering
snow-masses, are well known in lower latitudes. It is, however,
interesting for meteorologists to find that the same rules also apply
to the weather conditions at the Pole.
Now follows a period of prevailing southerly and southeasterly winds
which cause the temperature to rise quickly. On the coldest day, the
24th of May, there had been -12.5° c., but at the end of the month we
already had +7° c. and on the 7th of June the temperature was up to 0°.
This enormously quick change from winter to “summer temperature” is
typical of the polar conditions.
“Spring” does not last “month’s,” as in the lower latitudes--it is
finished in a few weeks’ time.
From the 7th of June onwards the temperature did not rise much; it
remained about 0°. Sometimes a little over, sometimes a little under.
One can say that 0° is the characteristic summer temperature of the
Arctic region. Warmer air than 0° is very often carried there from
lower latitudes, but this gets cooled down immediately through contact
with the ice, and gets a temperature of about 0°. As mentioned before,
it is this cooling down which is responsible for the fog because it
causes the air’s moisture to condense. The first fog, which extended
right down to the ground, was observed on the 2nd of June; the next was
on the 8th of June, and thereafter happened fairly often, so in the end
whole days free of fog were exceptions.
Luckily on the 15th of June, when the starting place was ready, there
was sufficient visibility for them to start and to find their way out
of their “Foggy” home.
THE END
Transcriber’s Notes
Punctuation, hyphenation, and spelling were made consistent when a
predominant preference was found in the original book; otherwise they
were not changed.
Simple typographical errors were corrected; unbalanced quotation
marks were remedied when the change was obvious, and otherwise left
unbalanced.
Illustrations in this eBook have been positioned between paragraphs
and outside quotations. In versions of this eBook that support
hyperlinks, the page references in the List of Illustrations lead to
the corresponding illustrations.
The table on page 175 was printed in a way that was difficult to
understand, so its appearance in this eBook may be incorrect.
Page 249: “we reached the N 24” was printed that way, but the narrative
suggests that it should be “N 25”.