Our polar flight

by Roald Amundsen; Lincoln Ellsworth

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.