Subarctic

Daylight at these latitudes is quite extreme between summer and winter due to its high latitude. Near the summer solstice for instance, subarctic regions can experience an all-night period of either civil, nautical, or astronomical twilight (or in the northern reaches full daylight), since the sun never dips more than 18 degrees below the horizon. Noctilucent clouds are best observed within this range of latitude.

Climate and soils

Subarctic temperatures are above 10 °C (50 °F) for at least one and at most three months of the year. Precipitation tends to be low due to the low moisture content of the cold air but isn't to the point to semiarid regions. Precipitation is typically greater in warmer months, with a summer maximum ranging from moderate in North America to extreme in the Russian Far East. Except in the wettest areas glaciers are not large because of the lack of winter precipitation; in the wettest areas, however, glaciers tend to be very abundant and Pleistocene glaciation covered even the lowest elevations. Soils of the subarctic are in which leaching of nutrients takes place even in the most heavily glaciated regions. The dominant soil orders are podsols and, further north, gelisols.

Subarctic regions are often characterized by taiga forest vegetation as deciduous trees can't withstand the long winters, though where winters are relatively mild, as in northern Norway, broadleaf forest may occur—though in some cases soils remain too saturated almost throughout the year to sustain any tree growth and the dominant vegetation is a peaty herbland dominated by grasses and sedges. Typically, there are only a few species of large terrestrial mammals in the subarctic regions, the most important being elk, moose (Alces alces), bears, reindeer (Rangifer tarandus), and wolves (Canis lupus). Agriculture is mainly limited to animal husbandry as many crops can't be grown here, though in some areas barley can be grown. Canada and Siberia are very rich in minerals, notably nickel, molybdenum, cobalt, lead, zinc and uranium, whilst the Grand Banks and Sea of Okhotsk are two of the richest fisheries in the world and provide support for many small towns.

Except for those areas that are well-drained or adjacent to warm ocean currents, there is almost always continuous permafrost due to the very cold winters and short summers. This means that building in most subarctic regions is very difficult and expensive: cities are very few (Murmansk being the largest) and generally small, whilst roads are also few. Subarctic rail transport only exists in Europe (lines to Narvik and Murmansk) and the Norilsk–Dudinka line in northern Siberia, as well as the Alaska Railroad in Alaska and short sections of rail lines in Canada reaching northward into the lower subarctic. An important consequence is that transportation usually tends to be restricted to "bush" planes, helicopters and, in summer, riverboats. In areas that receive lower rainfall they tend to be covered by grasslands.