The word "Arctic" brings to mind frozen ocean waters and barren tundra. It is a harsh landscape that attracts explorers and adventurers. In the winter, most of the Arctic is hidden away under snow and ice. Sea ice expands to cover the entire Arctic Ocean, and the Arctic lands—northern North America, Eurasia, and Greenland, gain a blanket of snow. In the summer, the sea ice retreats to the Central Arctic, opening channels and coastlines to open water. On land, the snow melts to expose tundra, which blooms with lichens, shrubs, and grasses.
The Arctic may be a forbidding place to travel, but its cold weather and unique climate patterns make it an important place for scientists to study. The Arctic influences the weather and climate of the entire Northern Hemisphere, and the cool northern region helps to moderate the climate of the rest of the planet.