Physical Environment: Arctic

Physical Environment Overview

All lines of longitude converge at the North Pole. The challenge to map makers is attempting to replicate that on a flat map. NATO militaries use the Military Grid Reference System (MGRS) as the geocoordinate standard for locating points on Earth. The MGRS is derived from the Universal Transverse Mercator (UTM) grid system and the universal polar stereographic (UPS) grid system, but uses a different labeling convention. In the Arctic region, this becomes extremely challenging with the convergence of the longitudinal lines, becoming noticeable north of the 60° latitude. For detailed information on the MGRS in polar regions, see DMA Technical Manual 8358.1, Datums, Ellipsoids, Grids, And Grid Reference Systems, Appendices A-D.

Military Grid Reference System for the North Pole

Land Environment

Climate

The Köppen climate classification places the Arctic in two categories: tundra climate (ET) and snow and ice climate (EF). Köppen’s type E climates are controlled by the polar and Arctic air masses of high latitudes (60°N and higher). These climates are characterized by low temperatures and precipitation and by a surprisingly great diversity of subtypes.

Tundra climate (ET). This major climate type of the Köppen classification is characterized by sub-freezing mean annual temperatures, large annual temperature ranges (but not as large as in the adjacent continental subarctic climate), and moderately low precipitation. The tundra climate region occurs between 60° and 75° of latitude, mostly along the Arctic coast of North America and Eurasia and on the coastal margins of Greenland. In areas dominated by the tundra climate type, winters are long and cold (temperatures may be below 0°C [32°F] for 6 to 10 months), especially in the region north of the Arctic Circle where, for at least one day in the year, the Sun does not rise. Winter precipitation generally consists of dry snow, with seasonal totals less than in the summer when cyclonic storms that develop along the boundary between the open ocean and sea ice yield rainfall. Typical annual totals are less than 35 cm (about 14 inches), but a range from 25 to 100 cm (10 to 39 inches) is possible, with higher totals in upland areas. In contrast, summers are generally mild, with daily maxima from 15 to 18°C (59°F to 64°F), although the mean temperature of the warmest month is less than 10°C (50°F). Days are long (a result of the high latitude), but they are often cloudy. The snow cover of winter melts in the warmer season (though in places with mean annual temperatures of −9°C [16°F] or less the ground at depth remains permanently frozen as permafrost); however, frosts and snow are possible in any month

Snow and ice climate (EF). This major climate type of the Köppen classification characterized by bitterly cold temperatures and scant precipitation. It occurs poleward of 65° N over the ice caps of Greenland the permanently frozen portion of the Arctic Ocean. It is abbreviated EF in the Köppen-Geiger-Pohl system. In snow and ice climate regions, temperatures are below freezing throughout the year, and annual temperature ranges are large but again not as large as in the continental subarctic climates. Winters are frigid, with mean monthly temperatures from −20°C to −65°C (–4°F to –85°F); the lowest temperatures occur at the end of the long polar night. Precipitation is meager in the cold, stable air (in most cases, 5 to 50 cm [2 to 20 inches]), with the largest amounts occurring on the coastal margins. Most of this precipitation results from the periodic penetration of a cyclone into the region, which brings snow and ice pellets and, with strong winds, blizzards. High winds also occur in the outer portions of the Greenland climates, where cold, dense air drains off the higher, central sections of the ice caps as katabatic winds. Daily temperature variations are very small, because the presence of snow and ice at the surface refrigerates the air.

Precipitation

Surprisingly for some, the Arctic is place of relatively low precipitation. According to Encyclopaedia Britannica, this is caused by “subsidence of air in the high-pressure belts and partly by the low temperatures. Snow or rain occur at times, but evaporation from the cold sea and land surfaces is slow, and the cold air has little capacity for moisture.”

Most precipitation in the Arctic comes in the form of snow. Snow particles constitute the clouds of cirrus type—namely cirrus, cirrostratus, and cirrocumulus—and many clouds of alto type. Ice and snow clouds originate normally only at temperatures some degrees below the freezing point; they predominate at −20°C (−4°F). In polar regions, snow particles “can occur near the surface and may appear as ice fogs. If cold air near the ground is overlain by warmer air (a very common occurrence in polar regions, especially in winter), mixture at the border leads to supersaturation in the cold air. Small ice columns and needles, ‘diamond dust,’ will be formed and will float down, glittering, even from a cloudless sky.” The presence of ice crystals in the atmosphere can cause optical effects around light sources appearing as halos, arcs, circles, mock suns, and coronas. Sunshine reflection from snow will cause severe sunburn on all exposed skin and damage to retinas. Units must issue effective sunglasses to prevent snow blindness in troops and sunblock creams to prevent sunburn.

When raindrops fall through a cold layer of air (colder than 0°C, or 32°F) and become super-cooled, freezing rain occurs. The drops may freeze on impact with the ground to form a very slippery and dangerous “glazed” ice that is difficult to see because it is almost transparent.

Midnight Sun

The midnight sun (also known as white nights or polar day) is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle, when the sun remains visible at the local midnight. Since the axial tilt of the Earth is approximately 23° 27”, the sun does not set at high latitudes in local summer. The midnight sun is visible at the Arctic Circle from 12 June until 1 July. At the pole itself, the sun rises and sets only once each year on the equinox. During the six months that the sun is above the horizon, it spends the days continuously moving in circles around the observer, gradually spiraling higher and reaching its highest circuit of the sky at the summer solstice.

Wind

Wind speeds over the Arctic Basin and the western Canadian Archipelago average between four and six meters per second (14 and 22 kilometers per hour [km/h], nine and 13 miles per hour [mph]) in all seasons. Stronger winds do occur in storms, often causing whiteout conditions, but they rarely exceed 25 meters per second (90 km/h, 55 mph) in these areas.

During all seasons, the strongest average winds are found in the North Atlantic seas, Baffin Bay, Bering Sea, and Chukchi Sea, where cyclone activity is most common. On the Atlantic side, the winds are strongest in winter, averaging seven to 12 m/s (25 to 43 km/h, 16 to 27 mph), and weakest in summer, averaging five to seven m/s (18 to 25 km/h, 11 to 16 mph). On the Pacific side they average six to nine m/s (22 to 32 km/h, 13 to 20 mph) year round. Maximum wind speeds in the Atlantic region can approach 50 m/s (180 km/h, 110 mph) in winter.

Terrain

Arctic ground is generally covered with ice or snow during the winter season. Although frozen ground and ice can improve trafficability, a deep accumulation of snow can reduce it. Vehicles and personnel require special equipment and care under these adverse conditions. Wheeled vehicles will need chains or studded snow tires. Dismounted troops will require winter clothing, skis, and snowshoes. Light infantry movement may take up to five times longer than in temperate terrain. Light infantry patrolling dismounted with combat loads and moving tactically can plan on a movement rate of 500 meters per hour.

Night navigation may be particularly enhanced when operating in Arctic terrain. Moonlight and starlight on a clear night reflect off the snow, thus enabling units to employ daytime terrain association techniques with little difficulty. Even cloudy winter nights are often brighter than clear moonlit summer nights when the ground is dark and covered with foliage. Movements with complete light discipline (no black-out drives) can often be executed. On the other hand, areas with severe winter climates experience lengthy periods of darkness each day, which may be accompanied by driving snow and limited visibility.

In relatively flat, open areas covered with snow (especially in bright sunlight), the resulting lack of contrast may interfere with being able to read the land. With foliage gone, concealment (both from the ground and from the air) is greatly reduced. As in desert areas, units must make better use of the terrain to conceal movement. Frozen streams and swamps are not a problem in the winter, but a major impediment to vehicle traffic during the Spring thaw and Summer months.

Tundra

The word “tundra” is often used to describe Arctic and sub-Arctic land areas. Specifically, tundra is a biome with long cold winters and short cool summers. The Arctic tundra has low precipitation (less than ten inches per year) and dry winds. These conditions make the Arctic tundra a desert-like climate. One unique characteristic of the Arctic tundra is permafrost--ground that is permanently frozen. The level of ground above the permafrost will defrost during summer allowing plants to grow. The growing season is 50-60 days only.

Arctic tundra has low plant diversity and mostly simple, hardy vegetation. It is treeless and mostly covered in wildflowers in the summer. Large shallow lakes exist melted into the permafrost and are referred to as thermokarst lakes.

Animal populations fluctuate throughout the seasons in the tundra biome. The food chain in the Arctic Tundra consists of predators such as owls, foxes, wolves, and polar bears at the top of the chain. Predators hunt herbivores, plant eating animals, such as caribou, lemmings, hares, mice, and shrews.

Types of Arctic Animal Life

Mammals	Arctic foxes, Arctic hares, lemmings, caribou, ermine, musk oxen, porcupines, polar bear, Arctic shrews, Arctic squirrels, voles, wolves, weasels, multiple species of whales
Birds	Arctic loons, snowy owls, falcons, ravens, snow birds, snow buntings, snow geese, sandpipers, tundra swans, Arctic terns, many species of gulls
Fish	Cod, trout, flatfish, salmon, sheefish
Insects	Arctic bumblebees, grasshoppers, blackflies, flies, moths, mosquitoes

Ground Pressure

Ground pressure is the pressure exerted on the ground by the tires or tracks of a motorized vehicle, and is one measure of its potential mobility, especially over soft ground. It also applies to the feet of a walking person or machine. Ground pressure is measured in pascals (Pa) which corresponds to the United States customary units unit of pounds per square inch (psi). Average ground pressure can be calculated using the standard formula for average pressure: P = F/A. In an idealized case, i.e. a static, uniform net force normal to level ground, this is simply the object's weight divided by contact area. The ground pressure of motorized vehicles is often compared to the ground pressure of a human foot, which can be 60 - 80 kilopascal (kPa) while walking or as much as 13 megapascal (MPa) for a person in spike heels.

Increasing the size of the contact area on the ground (the footprint) in relation to the weight decreases the ground pressure. Ground pressure of 14 kPa (2 psi) or less is recommended for fragile ecosystems like marshes (prevalent in the Arctic summer). Decreasing the ground pressure increases the flotation, allowing easier passage of the body over soft terrain. This is often observed in activities like snowshoeing.

Ground Pressure Examples

Object	Ground pressure (kPa)	PSI
Hovercraft	0.7	0.1
Human on snowshoes	3.5	0.5
Rubber tracked ATV	5.165	0.75
Wheeled ATV	13.8	2
Snowmobile	3.5	0.5
Crawler Carrier	35.16	5.1
Human male	55	8
BV-206 all terrain carrier	11.6/12.6	1.68/1.97
DT-30PM articulated track carrier	29.4	4.26
M1 Abrams main battle tank (MBT)	103	15
1993 Toyota 4Runner / Hilux Surf	170	25
T-90A MBT	92.18	13.37
BTR-D infantry fighting vehicle (IFV)	49.03	7.11
Marder 1A3 IFV	92.18	13.37
M113A1 armored personnel carrier	53.93	7.82

Maritime Environment

Arctic Ocean

The Arctic Ocean is the smallest of the world’s oceans and is centered on the North Pole. The marginal seas of the Arctic Ocean are the Chukchi Sea, East Siberian Sea, Laptev Sea, Kara Sea, Barents Sea, White Sea, Greenland Sea, Beaufort Sea, Bering Sea, and Norwegian Sea. Databases tend to be rather empty concerning these seas due to their remoteness, inhospitable weather, and seasonal or perennial sea ice. The total area of the Arctic Ocean is 14,090,000 km2 (5,440,000 sq mi). Average depth is 987 m (3,240 ft) with the deepest point at 5,502 m (18,050 ft).

The Arctic Ocean floor is split by an underwater mountain range (Lomonsov Ridge) making it actually two large basins: the Eurasia Basin and the Amerasia Basin. The Lomonsov Ridge was discovered by Donovian scientists in 1948-1949 and reported in 1954. According to the Encyclopaedia Britannica, the ridge “varies in width from 40 to 120 miles, and its crest ranges in depth between 3,100 and 5,400 feet."

Water in the Arctic Ocean moves in multiple layers. The water from surface to 200 m (650 ft) is variable due to the freeze/thaw cycle. The temperature is this layer varies 4°C and salinity 28-34 grams of salt per kilogram. The next layer is 650 – 3,000 ft and is warmer Atlantic Ocean water. The temperature of this layer is 1-3 C (34-37F) as it enters the Arctic Basin, but cools as it enters the Beaufort Sea to 0.5 to 0.6 °C (32.9 - 33.1 °F). The bottom layer beneath the Atlantic layer to the ocean floor. This is colder than the Atlantic water (below 32 °F, or 0 °C) but has the same salinity. In the Amerasia Bain, warmer low salinity Pacific Ocean water mixes with colder and denser Chukchi Sea water. This causes a wedge between the Arctic and Atlantic waters. Its temperature range is −0.5 to −0.7 °C.

Arctic waters are driven by the wind and by density differences. The effect of tides is unknown. The motion of surface waters is best known from observations of ice drift. The surface circulation pattern of the Amerasia Basin is a large clockwise gyre (circular motion) travelling at two orbits in 20 years. The northern portion splits off into the Greenland Current and reaches speeds of 6-16 inches per second. The Eurasia Basin circulation is counterclockwise with speeds of two inches per second. The circulation of bottom layer waters is unknown.

Sea Shipping Routes

The two major shipping routes through the Arctic are the Northern Sea Route (also known as the Northeast Passage) and the Northwest Passage. Ocean depths along these routes range from 200 meters to 5,000 meters (see bathymetry graphic).

The Northern Sea Route was first conquered by Adolf Erik Nordenskiöld's Vega expedition, 22 June 1878 through 20 July 1879. It extends east of Novaya Zemlya and specifically runs along the Donovian Arctic coast from the Kara Sea, along Siberia, to the Bering Strait. The entire route lies in Arctic waters and within Donovia's Exclusive Economic Zone (EEZ). Parts are free of ice for only two months per year. While this route includes all the East Arctic seas and connects the Atlantic and Pacific oceans, the Northern Sea Route does not include the Barents Sea, and it therefore does not reach the Atlantic.

Donovia issues navigation permissions and provides support activities along the route. Future plans include extensive infrastructure growth to provide electricity and refueling sites. Since 2010, the number of transits through the Northern Sea Route have been dropping. The number of complete passages per flag country:

Northern Sea Passages Per Flag Country

Year	Donovia	Singapore	Bothnia	Norway	Germany	Spain	Olvana	Greece	Hong Kong	Torrike	Holland
2011	26	4	2	2	1	1
2012	18		6	5			2
2013	46		2	2				2	1
2014	47									3
2015	10						2			1	1
2016	7				1				2

In August 2017, the first ship traversed the Northern Sea Route without the use of ice-breakers.

The Northwest Passage (NWP) is a sea route connecting the Atlantic and Pacific Oceans via the Arctic Ocean through the Canadian Arctic. The northern route was discovered in 1850 by Irish explorer Robert McClure. Scottish explorer John Rae discovered a southern routes in 1854. Norwegian Roald Amundsen completed the first complete passage, 1903-1906. Arctic sea ice decline has allowed more freedom of ice navigation since 2009. The Northwest Passage includes three sections:

• East: East of Baffin Island: Baffin Bay between Greenland and Baffin Island to Lancaster Sound at the north end of Baffin Island, or West of Baffin Island (impractical): Through Hudson Strait south of Baffin Island, north through the Foxe Basin, west through the Fury and Hecla Strait, north to Lancaster Sound through the Gulf of Boothia and Prince Regent Inlet. The Fury and Hecla Strait is usually closed by ice.
• Center: Canadian Arctic Archipelago North: From Lancaster Sound west through the Parry Channel to the Prince of Wales Strait on the northwest side of Victoria Island. M'Clure Strait to the northwest is ice-filled; southwest through the Prince of Wales Strait between Victoria Island and Banks Island might be passable, or South: From Lancaster Sound west past Prince Regent Inlet (basically a cul-de-sac but it may be possible to exit west through the Bellot Strait), past Somerset Island, south through Peel Sound between Somerset Island and Prince of Wales Island, either southwest through Victoria Strait (ice-choked), or directly south along the coast through Rae Strait and James Ross Strait and west through Simpson Strait south of King William Island (shallow) into Queen Maud Gulf, then west along the mainland coast south of Victoria Island.
• West: There being no major islands, follow the coast to the Bering Strait.

Map of the Arctic Region showing the Northern Sea Route and the Northwest Passage

Poles

The term “North Pole” is one sometimes used incorrectly. There are actually four poles in the Arctic: the North Pole, the North Magnetic Pole, the North Geomagnetic Pole, and the Northern Pole of Inaccessibility. A geomagnetic pole is an antipodal point where the axis of a best-fitting dipole intersects the surface of the Earth. This theoretical dipole is equivalent to a powerful bar magnet at the center of Earth and comes closer than any other model to accounting for the magnetic field observed at Earth's surface. In contrast, the magnetic poles of the Earth are not antipodal; that is, the line on which they lie does not pass through Earth's center. A pole of inaccessibility marks a location that is the most challenging to reach owing to its remoteness from geographical features that could provide access. Often it refers to the most distant point from coastlines.

The North Pole (also known as the Geographic North Pole or Terrestrial North Pole), is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. The North Pole is the northernmost point on the Earth, lying diametrically opposite the South Pole. It defines geodetic latitude 90°North, as well as the direction of true north. At the North Pole all directions point south; all lines of longitude converge there, so its longitude can be defined as any degree value. Along tight latitude circles, counterclockwise is east and clockwise is west. The North Pole is at the center of the Northern Hemisphere. The sea depth at the North Pole has been measured at 4,261 m (13,980 ft) by the Donovian Mir submersible in 2007.

The North Magnetic Pole (also known as the Magnetic Dip Pole) is the wandering point on the surface of Earth's Northern Hemisphere at which the planet's magnetic field points vertically downwards (in other words, if a magnetic compass needle is allowed to rotate about a horizontal axis, it will point straight down). The North Magnetic Pole moves over time due to magnetic changes in the Earth's core. In 2001, it was determined by the Geological Survey of Canada to lie west of Ellesmere Island in northern Canada at 81.3°N 110.8°W. It was situated at 83.1°N 117.8°W in 2005. In 2009, while still situated within the Canadian Arctic territorial claim at 84.9°N 131.0°W, it was moving toward Donovia at between 55 and 60 kilometers (34 and 37 mi) per year. By 2017, the pole had moved beyond the Canadian Arctic territorial claim to 86.5°N 172.6°W.

The North Geomagnetic Pole is the center of the 'open' magnetic field lines which connect to the interplanetary magnetic field and provide a direct route for the solar wind to reach the ionosphere. As of 2015, it was located at approximately 80.37°N 72.62°W, on Ellesmere Island, Nunavut, Canada. The locations of geomagnetic poles are predicted by the International Geomagnetic Reference Field, a statistical fit to measurements of the Earth's field by satellites and in geomagnetic observatories.

The Northern Pole of Inaccessibility (also known as the Arctic pole of inaccessibility and the Arctic pole) is located on the Arctic Ocean pack ice at a distance farthest from any land mass. It lies at 85°48′N 176°9′W, 1,008 km (626 mi) from the three closest landmasses: Ellesmere Island, Komsomolets Island, and Henrietta Island. Due to constant motion of the sea ice, no permanent structure can exist at this pole.

Sea Ice

The cover of sea ice (above latitude 60°N) reflects most of incoming solar radiation and keeps the surface temperatures low. Wind and water keep the ice in constant motion causing cracks, open ponds, and pressure ridges. Pressure ridge can stack very high, and reach down in the water 10-25 m (33-80 ft). Sea ice in the Arctic Ocean generates cold water that drives the circulation of the world ocean system.

The impact of global warming on Arctic Ocean sea ice is expected to continue. This graphic shows the U.S. Navy’s prediction of open water availability and the number ships passing through the Bering Strait, the Northern Sea Route (NSR) (4,740 nautical miles), the Northwest Passage (5,225 nautical miles), and the Transpolar Route (4,170 nautical miles), 2012-2030.

Arctic Sea Route Navigability

Much has been researched, written, and argued over concerning the extent of Arctic Ocean sea ice. These two graphics show some of the data. One is a graphic from the National Snow and Ice Data Center showing the Arctic Ocean sea ice extent for the months of September and March of each year from 1979 through 2016. September and March are when the minimum and maximum extent typically occur each year. The other shows the range of Arctic Ocean sea ice, 1979-2007 as observed by the National Aeronautics and Space Administration (NASA).

Climate Change Indicators- Arctic Sea Ice, 1979-2016

The Arctic as observed by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) aboard NASA’s Aqua satellite on September 16, 2007

Icebergs

In the Arctic Ocean, the highest latitude sources of icebergs are Svalbard archipelago north of Norway and the islands of the Donovian Arctic. 26% come from Svalbard, 36% from Franz Josef Land, 32% from Novaya Zamlya, 6% from Severnaya Zemlya, and .3% from Ushakov Island. These primarily affect travel in the Barents or Kara Seas. In the Amerasia Basin, most Arctic icebergs originate from the Greenland ice sheet. Arctic icebergs tend to be smaller and more randomly shaped than Antarctic icebergs. Most icebergs are actually ice islands. Ice islands produced by Ellesmere Island calve into the Beaufort Gyre.