The Arctic, a remote region at the top of our planet, is defined by its unique features, extreme climate, and remarkable ecosystems. Understanding the Arctic involves recognizing its boundaries and the life that thrives there. This region influences global systems far beyond its icy expanse.
Defining the Arctic
The Arctic is primarily defined by the Arctic Circle, an imaginary line of latitude located at approximately 66.5 degrees North. This geographical marker indicates the southernmost point where, for at least one full day each year, the sun either remains continuously above the horizon during summer or continuously below it during winter. The position of this circle slowly shifts northward by about 14.5 meters annually due to variations in Earth’s axial tilt.
Other definitions also delineate the region. Ecologists consider the Arctic as the area where the average July temperature remains below 10 degrees Celsius (50 degrees Fahrenheit), largely corresponding to the northern tree line. The Arctic Ocean, the smallest and shallowest of the world’s five oceans, covers approximately 14 million square kilometers. Surrounding this ocean are landmasses belonging to eight countries: Canada, Denmark (via Greenland), Finland, Iceland, Norway, Russia, Sweden, and the United States (Alaska).
The Arctic Environment
The Arctic experiences long, cold winters and short, cool summers. Winter temperatures can drop to -40 degrees Celsius (-40 degrees Fahrenheit), with some Siberian regions averaging below -40 degrees Celsius in January. Precipitation is low, mostly snow, with many areas receiving less than 50 centimeters (20 inches) annually. High winds frequently stir up this snow.
Extensive ice presence defines the Arctic. The Arctic Ocean is largely covered by sea ice, thickening in winter and shrinking in summer. This sea ice reaches its maximum extent in March and minimum in September. The Greenland Ice Sheet is another significant feature.
The aurora borealis, also known as the northern lights, is commonly observed. These light displays occur when charged particles from the sun interact with gases in Earth’s upper atmosphere.
Life in the Arctic
Despite extreme conditions, the Arctic supports diverse ecosystems. Animals have developed adaptations to survive the cold, seasonal light changes, and find food. Marine mammals like polar bears, seals, whales, and walruses thrive in Arctic waters and on its ice. Polar bears rely on sea ice for hunting seals, their primary food source.
Bird species migrate to the Arctic for breeding during warmer months, utilizing abundant insect life from the thawing tundra. Terrestrial animals like Arctic foxes and caribou inhabit the land, adapting their coats and behaviors. Plant life is tundra vegetation, including low-growing shrubs, grasses, mosses, and lichens. These plants adapt to short growing seasons and permafrost, the permanently frozen ground.
Human Presence and Exploration
Humans have inhabited the Arctic for thousands of years, with Indigenous communities deeply connected to this environment. Groups like the Inuit, Sami, Chukchi, Aleut, and Yupik represent over 40 distinct ethnic groups across the circumpolar region. Approximately 400,000 Indigenous people, about 10 percent of the Arctic’s four million total population, practice traditional livelihoods such as hunting, fishing, and reindeer herding. Their traditional knowledge of the land and ice has been essential for survival and navigation.
European exploration began in the 10th century with Vikings reaching Greenland. Later expeditions, starting in the 16th century, sought new trade routes like the Northwest Passage and Northeast Passage, and aimed for scientific knowledge. Modern human presence includes scientific research stations that study climate, oceanography, and ecosystems. These stations aid understanding global environmental changes.
The Arctic’s Role in Global Systems
The Arctic plays a role in regulating Earth’s climate and influencing global weather patterns. Extensive ice cover, particularly sea ice, acts as a reflective surface, bouncing sunlight back into space and cooling the planet. This phenomenon, the albedo effect, is a component of Earth’s energy balance.
As the Arctic warms faster than the global average, melting sea ice contributes to rising sea levels and impacts ocean currents. Changes in Arctic temperatures and ice cover can affect the jet stream, a high-altitude air current influencing lower latitude weather patterns. Alterations to the jet stream can lead to more extreme weather events, such as droughts, heatwaves, and storms, far from the Arctic. Changes in this remote region have widespread implications for the entire planet.