Scientific studies made during the solo-dogsled journeys to the North Pole and across Greenland*
(1) Introduction
Prior to Uemura, others had reached the pole but few had made observations or collected samples of snow, aerosols (particles in the air), etc. as described hereunder. Since his route from north to south on the Greenland ice sheet had never been trodden by human beings before, Uemura’s observations on snow, ice and glacier conditions, and samplings are significant.
The North and South Poles are quite different, one being a sea and the other a continent, but both have in common an extensive snow and ice covering and they both have a great effect on global weather and climate.
While the history of antarctic expeditions only goes back as far as James Cook’s attempt in the 18th century, arctic expeditions started much earlier. The Vikings settled in Iceland as early as the 8th century and in the 10th century they reached Greenland. The number of Vikings in Greenland is considered to have reached 9,000. (1) What did the Eskimos, the aborigines of Greenland, call their island? We have a document stating that the Vikings called it “Greenland”. Besides their intention to attract people to the island by the suggestive name “Green Land”, they must have actually thought of it as an island of green leaves and grasses. At the time, willows, birch trees and green pastures were seen around the fjords and the climate was much milder than now. It became colder by the 15th- 16th century and all the descendants of the Vikings are said to have perished. (1) This is an example of how a change in climate had a great impact on human life. From the 15th/16th century the earth entered the cold period called the “Little Ice Age”, during which some glaciers in the mountain areas are known to have expanded.
During the ice age more than 10,000 years ago, ice sheets developed in North America, Europe and Siberia, of which the Greenland ice sheet is the only one remaining in the northern hemisphere. In 1888 Nansen and his group, searching for the unknown in this white land, succeeded in a latitudinal crossing of Greenland for the first time. Subsequently, the veils of mystery surrounding Greenland were lifted one by one by the North Greenland journey (1905 – 1906) of a team led by Peary, who hoped ultimately to reach the North Pole, a journey in the northwest area of Greenland (1916 -1919) by the Rasmussen (Denmark) team, and a traverse of Greenland (1930 – 1931) by Watkins (Great Britain) and his group.
The two basins on the Atlantic side of the Lomonosov Ridge which runs through the middle of the Arctic Ocean are called Nansen Basin and Amundsen Basin. They were named after Nansen who, while exploring in the drifting boat “Fram” in 1893-96, attained the northernmost point at the time and contributed to oceanography; and Amundsen, who succeeded in opening the northwest route (1903 – 1906) and flying across the Arctic Ocean from Spitsbergen to Alaska via the North Pole (1926) in the airship “Norge”. Robert Peary was the first person to reach the North Pole in 1909. Through these explorations, people came to know about the Arctic Ocean bit by bit. The age of geographic discoveries is said to have ended with the discovery of Severnaya Zemlya in 1913.
Unexpectedly, however, soon after the end of the World War 11, an island partly covered by rocks was found at a point 500 km off Point Barrow, Alaska in the Arctic Ocean. Upon further investigation it became known that it was not really land but was drifting, and it came to be called an ice island.
Higuchi joined the glaciolgy/oceanography study group on Ice Island “T-3” in 1960. Fushimi engaged in oceanographical observations on Ice Island “Arlis 11” from 1963 to 1965. Studies of the rocks on the ice islands suggested that these ice islands were originally part of the ice shelf and glacial ice formed near the seashore around Ellesmere Island.
These ice islands are about 50 meters thick and serve, so to speak, as “natural ice breakers” floating on the Arctic Ocean, the average thickness of the sea ice being a few meters, and they are used as bases for scientific observations. Ice islands drift according to the wind and ocean currents. The direction of drifting is clockwise on the Beaufort Sea on the North American side of the pole as can be seen in the drifting course of T-3. Arlis I1 took the same direction as that on which the Papanin team drifted on the North Pole I in 1937, i. e., from west to east in the sea on the Asia/ European side of the North Pole. Between the pole and Greenland/Ellesmere Island, ice advances toward the land, the pressure of which particularly helps ice ridges develop. As Uemura described it, “Climbing an ice ridge, I looked for the next flat ice but to no avail. Giving up, I started opening a path inch by inch. I had to repeat the same action endlessly.” (2)
During the period from 1960 to 1966 a boring core down to the ice sheet base as deep as 1,387.4m was collected at Camp Century (77.Z0N, 61.1°W, 1,885 m above sea level). Dansgaard (Denmark) and others deduced past temperatures from the oxygen isotope ratio and showed the history of climatic changes dating hack almost 20,000 years by an analysis of a core at one spot. (8)
On the other hand, Benson (USA), who made extensive survey trips (1952 – 1954) in the inland regions of Greenland, distinguished four snow facies, i. e., dry snow facies, percolation facies, wet snow facies and ablation facies. He indicated that their distribution had a close relationship with meteorological conditions.(4)
Snow conditions greatly affected Uemura’s sled journeys. He writes about the advance of his sled on the Arctic Ocean; “It is -34°C. The runners of my sled do not slide because of the low temperatui-e. With snow clinging to the runners, I feel its heaviness as if my sled is running on sand.” (2) He experienced a similar difficulty caused by low temperatures on the northern region of the Greenland ice sheet.
Unlike the preceding expeditions/investigations in the arctic region, Uemura reached the pole alone and also accepted the challenge of a traverse of Greenland from north to south, which none had attempted before. In a case like this, no sophisticated observations or investigations could be expected. Investigations and collection of basic information which could be done by light instruments were planned.
The following is the report presented by Higuchi and Uemura at the first lecture meeting of the Japanese Alpine Club Scientific Research Committee held on March 19, 1979, plus results of analyses conducted after the meeting.
(2) Contents of investigations
It is about 3,000 km in tangent from the pole to the southern end of Greenland. The distance actually travelled by Uemura was far longer. When one travels in an extensive area and is required to move fast, long-term study and observations at a certain place are difficult. In this study he concentrated on collecting samples of fresh snow, snow-cover and aerosols. Collection of these samples is relatively easy and gives us basic information about weather and climate.
(2-1) Investigation of snow
When snow falls on an ethylene dichloride solution of a synthetic resin called polyvinyl formvar, ethylene dichloride evaporates leaving a thin film of resin showing the surface structure of snow crystals and shapes. Uemura, using this method (known as “replica”), put on record crystals of falling snow and at the same time took photographs of snow which had fallen on black woolen cloth together with a scale indicating size. From these photos we can figure out the intensity of the snowfall, as we have records of the exposure time. As Fig. 2 shows, observations were conducted at 19 points in Greenland and Ellesmere Island. The purpose of these investigations was to probe the relationship between kinds of snow crystals and the intensity of the snowfall and meteorological conditions.
(2-2) Collection of snow samples
(3) Results of investigation
(3-1) Weather conditons
The average annual temperature distribution of the northern hemisphere for the period from 1921 to 1950 shows: 1) the coldest regions with average temperatures below -30°C are in Siberia and northern Canada from November to February; 2) in March the average temperature in almost the entire area of the Arctic Ocean goes up to -28’C; 3) in April in the central area of the Arctic Ocean the average temperature rises to -20°C and in the southernmost part of Greenland it reaches 0°C; 4) subsequently, the temperature keeps going up, and in August, the warmest season, in most of the Arctic Ocean the temperature reaches +4″C and +8″C in the southern part of Greenland; and 5) then, the average temperature quickly drops toward what it is during the coldest season.(6)
As shown in Table 1, the air temperature was measured at about 12:OO GMT, which is early morning local time (Resolute Time). According to the records of the “North Pole 6” and “T-3″ Ice Island observations(@, the daily range of temperatures on the Arctic Ocean in March through April averages 4” to 5°C.
The minimum temperature observed during the investigation on the Arctic Ocean was -51°C recorded at the Aurora Base Camp, the departure point at the northern tip of Ellesmere Island, on March 5, and the maximum temperature was -11’C recorded at a point near the pole (88’51’N, 76″17’W)
on April 27. In March a rising tendency in the air temperature corresponds closely with the weather conditions, namely, high temperatures were recorded on days of snow and blizzard, March 8, 11, 16 and 23-24. This was probably caused by the advance of low pressure with warm air from south.
Fig.5 shows that the west wind dominates in the area south of 87″N, whereas the north wind dominates north of 87″N in the Arctic Ocean. Two areas of drifting sea ice are separated in the sea area between the pole and Greenland, that is, one rotating the Beaufort Sea clockwise and the other drifting southward along the east coast of Greenland. These characteristics of drifting sea ice are explained by the north wind that carries ice from the pole to Ellesmere Island and the west wind that helps the ice ride on the east Greenland current.
The weather chart of Greenland (Table 2) indicates there was a low temperature period from the end of May through June. This may have been caused by the increase in the altitude of observation points as the observer was travelling on the ice sheet from north to south. On the other hand, the high temperature tendency after July that sometimes reached as high as 0°C is considered to be caused by the high temperatures of the warmest month of the year, the influence of which had finally reached the inland region of the ice sheet. On July 14 the record showed rain at a point close to 72’N about 3,000 m above sea level on the inland ice sheet of Greenland.
Uemura, starting from Independence Fjord located at the north end of Greenland, reached the ice sheet via a route along the Academy Glacier. When he went up the glacier in order to avoid the crevasses, he advanced through a dry ditch. Such dry ditches of 4 – 10 meters in width and 2 – 7 meters in depth, which were often seen in this area, are thought to have been formed on the surface of the glacier by the erosion of melting water in summer. The formation of these ditches indicates that even in the glaciers at the north end of Greenland near the point 82″N, not only calving (a phenomemon in which the end of the glacier cracks off and floats out to sea or into a lake) but the melting of the glacier surface contributes to the ablation process of the glacier.
The chart indicating the direction and force of winds on the Greenland ice sheet (Fig. 5) shows that the west wind dominates in the northern part of the ice sheet and the east or south wind in the southern area. The wind shifting point is approximately the highest place on the ice sheet (around 72″N).
As Uemura reported, although the temperature rose in the afternoon and the surface of the snow-cover got partly wet in the area north of 72″N – 73″N, generally the snow-cover became hard like a slab. He mentioned that this injured his sled dogs’ paws.(2) According to Benson’s account of the distribution of snow facies, the southern end of this dry snow facies on the line of 40″W is somewhere around 70°N, about 300 km removed from the facies of Uemura’s report. The latter observed the south limit of the dry snow facies at a point around 73″N (Fig. 6). The investigation was conducted in the warmest months on the Greenland ice sheet, during which distribution of dry snow facies shrinks to the minimum. Therefore, it was the most suitable period to observe the distribution of the dry snow facies that is invariable regardless of the seasons.
The Greenland ice sheet is highest at around 71°N, 38″W, where the height exceeds 3,000 m. On the route crossing Greenland from north to south, the highest point Uemura passed was 3,230 m near 72″N, 40″W on July 12. Judging from the snow-cover conditions, the dry snow facies that has the most typical inland characteristics did not show a concentric distribution around the highest point of the ice sheet, but the distribution was in the direction of north from the highest point (Fig. 6). This is because advancing warm air masses, being hindered by the watershed on the ice sheet, cannot reach the northern part. This area therefore remains dry and cold. The annual accumulation pattern of snow on the Greenland ice sheet indicates that both dry snow facies and the areas with less snow accumulations are concentered in the northern part.(4) The lowest temperature which Uemura experienced on the Greenland ice sheet was on June 22 at a point near 76.5″N, 39’W. It was -26°C. The area is the center of the dry snow facies distribution. While running his sled on this dry snow area, Uemura encountered a sudden fall of the snow surface about 10 cm. It was thought that the surface fell on account of the depth-hoar layer of the snow being crushed by the weight of the sled.
A stretch of dunes (accumulated snow in the shape of sand hills) from east to west in this area (Fig. 6) is caused by the prevailing wind from the west, which often blows on the northern ice sheet. As is seen
from the characteristics of the wind directions on the Greenland ice sheet (Fig. 5), except the north/south winds blowing down along the slope in the central area near the highest point, the west wind prevails in the major portion of the northern ice sheet and the east wind in the southern ice
sheet. This fact indicates that a strong katabatic wind (wind descending a slope) similar to that often encountered on the antarctic ice sheet is not developed on the Greenland ice sheet during May through August.
As mentioned above, the cold period observed on the northern part of the Greenland ice sheet from late May to June (Table 2) is not caused only by the high altitude, but dry and cold climatic conditions with dry snow facies are thought also to contribute to the low temperatures.
In the area south of the highest point, the snow-cover changed to the percolation facies. In this connection, Uemura described the snow conditions as follows : “The snow gradually gets wet and sticks to the soles of the dogs’ paws. It grows to a large ball like the snow that balls up between the supports of wooden clogs. Their ability to run being impaired, the dogs try to bite off the snow ball from their paws. They do it hastily, without slowing their pace. While they are repeating their bites, fur starts coming off with the stuck snow and their paws bleed.” (2) Not only hardened dry snow and snow-cover at low temperatures but also wet snow became quite an obstacle to the dogsled journey.
The snow-cover in the area lower than a nunatak (6l039’N, 44″15’W) near the southern end of the ice sheet shifted to the wet snow facies and in some places ponds and streams were formed. As written by Uemura, “From here starts the Corpukselmia Glacier going down to Narssarssuaq. There are countless hidden crevasses in this glacier. It is practically impossible to pass through it by dogsled in the snow-thawing summer season.” At this point he completed his investigation journey on the ice sheet through both the dry snow facies and the wet snow facies.
(3-3) Snow crystals
According to Nakaya’s study of artificial snow, the temperature range necessary to form dendritic crystals is from -17°C to -14°C. (n Since the temperature was -10°C when the dendritic crystals were found, if the moist adiabatic lapse rate is taken as 0.7″C/100 m (average figure of moist adiabatic
lapse rate at -10°C and -15’C at 750 mb corresponding to the observation point), the height at which the dendritic crystal is formed is calculated to be 600 to 1,000m above the observation point, i. e., at an altitude of 2,950 – 3,350m. We did not see crystals with cloud droplets made by supercooled water drops in the dendritic crystals shown in Fig. 7. Therefore, that suggests that the stratus clouds were formed of snow crystals only and the top of the cloud reached 3,35Om, which is the highest limit for dendritic crystals to be formed. Nakaya’s experiment shows that at temperatures between -14% and -17’C the weather conditions to form dendritic crystals require a higher saturation ratio of ice than those to form column-with-plate crystals or bullet-with-plate crystals. (7) On the ice sheet the temperature increased only 2 degrees between 01:OO and 14:00 GMT. Assuming there was not much change in temperature at the high altitude where snow was formed, it can be considered that the weather condition at an altitude of about 3,000 m on June 20 changed from dry to wet. There are similar reports on weather conditions deduced from snow crystals at high altitudes observed by Higuchi (1976, 1978) in the Himalayan region.(8)
At 19:OO GMT on July 16 (71″22.CN, 4l042.9’W, at 2,900 m) and 20:00 GMT on July 30 (67″24.8’N, 44″36.7’W, at 2,300 m) both at -2″C, cumulus cloud cover, dendritic crystals were observed. The heights of the cloud summit at these times calculated by the above-mentioned method are 5,000 m and 4,400 m respectively. This shows that in the soutern part of the Greenland ice sheet, cumulus convection reaches approximately 5,000 m. This figure is very low in comparison with that in Japan, which is located at a middle latitude, where cumulus convection often reaches as high as 10,000m in July.
We would like to express our sincere appreciation to the many people who supported the solo dogsled journeys to the North Pole and across Greenland, Dr. Eizaburo Nishibori, Mr. KO Yoshida, Dentsu Inc., Bungei Shunju Ltd., Mainichi Newspapers, Mainichi Broadcasting System, Dr. Lee Houchins of the Smithsonian Institution, Dr. Yasushi Kitano of the Water Research Institute (Nagoya University), NASA, the National Geographic Society, the Northwest Territory of the Canadian Government, the Greenland Ministry of Denmark, the base camp crew; Mr. Yuko Tada, Mr. Kikuji Suzuki and Mr. Mutsuhiko Masuda.
References
(1) Stefansson, V. (1962) : Unsolved mysteries of the Arctic. Collier Books, New York, 320 pp.
(2) Naomi Uemura (1978): Solo journeys to the North Pole and across Greenland. Bungei Shunju Ltd., 261 pp.
(3) Dansgaard, W., Johnsen, S. J., M$ller, J. and Langway, C. C. Jr. (1969) : One thousand centuries of climatic record from Camp Century on the Greenland ice sheet. Science, 166, 377-381.
(4) Benson, C. S. (1962) : Stratigraphic studies in the snow and firn of the Greenland ice sheet. U. S. Army Snow Ice and Permafrost Research Establishment, Research Report 70, 93 pp.
(5) Japan Meteorological Association (1963) : Monthly mean surface temperature anomaly charts for the northern hemisphere (1921-1950).
(6) Vowinckel, E. and Orvig. S. (1970) : The climate of the North Polar Basin. Climate of the Polar regions, World Survey of Climatology. Vol. 14, S. Orvig ed., Elsevier, Amsterdam, 129-252.
(7) Nakaya, U. (1954) : Snow crystals, natural and artificial. Harvard University Press, 510 pp.
(8) Higuchi, K. (1976): Snow crystals observed at Lhajung station in Khumbu region. Seppyo, Vol. 38, Special Issue, 93-101.