The Arctic is the Earth region that lies between 66.5°N and the North Pole. In addition to being defined as 66.5°N of the equator, the specific border of the Arctic region is defined as the area in which average July temperatures follow the 50°F (10°C) isotherm (map). Geographically, the Arctic spans the Arctic Ocean and covers land areas in parts of Canada, Finland, Greenland, Iceland, Norway, Russia, Sweden and the United States (Alaska).
Geography and Climate of the Arctic
The majority of the Arctic is composed of the Arctic Ocean which was formed when the Eurasian Plate moved toward the Pacific Plate thousands of years ago. Although this ocean makes up the majority of the Arctic region, it is the world's smallest ocean. It reaches depths of 3,200 feet (969 m) and is connected to the Atlantic and the Pacific via several straits and seasonal waterways such as the Northwest Passage (between the U.S. and Canada) and the Northern Sea Route (between Norway and Russia).
Since the majority of the Arctic is the Arctic Ocean along with straits and bays, much of the Arctic region is composed of a drifting ice pack which can be up to nine feet (three meters) thick during winter. In the summer, this ice pack is replaced mainly by open water that is often dotted with icebergs that formed when ice broke from land glaciers and/or chunks of ice that have broken away from the ice pack.
The Arctic region's climate is very cold and harsh for most of the year due to the Earth's axial tilt. Because of this, the region never receives direct sunlight, but instead gets rays indirectly and thus gets less solar radiation. In the winter, the Arctic region has 24 hours of darkness because the high latitudes such as the Arctic are turned away from the sun at this time of year. By contrast in the summer, the region receives 24 hours of sunlight because the Earth is tilted toward the sun. However because the sun's rays are not direct, summers are also mild to cool in most parts of the Arctic.
Because the Arctic is covered with snow and ice for much of the year, it also has high albedo or reflectivity and thus reflects solar radiation back into space. Temperatures are also milder in the Arctic than in Antarctica because the presence of the Arctic Ocean helps moderate them.
Some of the lowest recorded temperatures in the Arctic were recorded in Siberia around -58°F (-50°C). The average Arctic temperature in the summer is 50°F (10°C) although in some places, temperatures can reach 86°F (30°C) for short periods.
Plants and Animals of the Arctic
Since the Arctic has such a harsh climate and permafrost is prevalent in the Arctic region, it mainly consists of treeless tundra with plant species such as lichen and mosses. In the spring and summer, low-growing plants are also common. Low growing plants, lichen and moss are most common because they have shallow roots which are not blocked by the frozen ground and since they do not grow into the air, they are less prone to damage by high winds.
The animal species present in the Arctic varies based on the season. In the summer, there are many different whale, seal and fish species in the Arctic Ocean and the waterways surrounding it and on land there are species such as wolves, bears, caribou, reindeer and many different types of birds. In the winter however, many of these species migrate south to warmer climates.
Humans in the Arctic
Humans have lived in the Arctic for thousands of years. These were mainly groups of indigenous peoples such as the Inuit in Canada, the Saami in Scandinavia and the Nanets and Yakuts in Russia. In terms of modern inhabitation, many of these groups are still present as are territorial claims by the aforementioned nations with lands in the Arctic region. In addition, the nations with territories bordering the Arctic Ocean also have maritime exclusive economic zone rights.
Because the Arctic is not conducive to agriculture due to its harsh climate and permafrost, the historic indigenous inhabitants survived by hunting and gathering their food. In many locations, this is still the case for the surviving groups today. For example Canada's Inuit survive by hunting animals such as seals on the coast during the winter and caribou inland during the summer.
Despite its sparse population and harsh climate, the Arctic region is important to the world today because it has significant amounts of natural resources. Thus, this is why many nations are concerned with having territorial claims in the region and in the Arctic Ocean. Some the major natural resources in the Arctic include petroleum, minerals and fishing. Tourism is also beginning to grow in the region and scientific exploration is a growing field both on land in the Arctic and in the Arctic Ocean.
Climate Change and the Arctic
In recent years, it has become known that the Arctic region is extremely susceptible to climate change and global warming. Many scientific climate models also predict larger amounts of climate warming in the Arctic than on the rest of the Earth, which has raised concerns about shrinking ice packs and melting glaciers in places like Alaska and Greenland. It is believed that the Arctic is susceptible mainly because of feedback loops- high albedo reflects solar radiation, but as sea ice and glaciers melt, the darker ocean water begins to absorb, instead of reflect solar radiation, which further increases temperatures. Most climate models show near to complete loss of sea ice in the Arctic in September (the warmest time of year) by 2040.
Problems related to global warming and climate change in the Arctic include loss of habitat critical habitat for many species, rising sea levels for the world if sea ice and glaciers melt and a release of methane stored in permafrost, which could exacerbate climate change.
National Oceanic and Atmospheric Administration. (n.d.) NOAA Arctic Theme Page: A Comprehensive Resrouce. Retrieved from: http://www.arctic.noaa.gov/
Wikipedia. (2010, April 22). Arctic - Wikipedia, the Free Encyclopedia. Retrieved from: http://en.wikipedia.org/wiki/Arctic