Circumpolar WHERE ARE THE POLAR REGIONS ARCTIC The Arctic surrounds the North Pole and can be defined in several ways In this book the Arctic refers to the tundra a land based habitat so cold and dry that trees can't grow Cold oceans surrounding the tundra are considered part of the Arctic too Arctic Circle Tundra Antarctica South Pole Alaska Arctic Canada Antarctica Russia North Pole Greenland ANTARCTICA Antarctica surrounds the South Pole and is defined by a current of moving water within the ocean The Antarctic Circumpolar Current is the longest strongest ocean current on the planet This current encircles Antarctica keeping the cold Southern Ocean isolated from warmer oceans to the north It's the main reason Antarctic habitats have remained unchanged for millions of years Antarctic Circle Antarctic Current
June MIDNIGHT SUN AND POLAR NIGHT The polar regions get different amounts of sunlight at different times of year That's because the Earth is tilted on its axis as it orbits travels around the sun In March the Arctic tips toward the sun causing sunrise at the North Pole This begins a period of constant daylight called the midnight sun In September Antarctica tips toward the sun As the midnight sun starts at the South Pole the North Pole enters a period of constant darkness called polar night At the poles the midnight sun and polar night last six months each As you travel farther and farther away from the poles these periods of continuous daylight and darkness get shorter and shorter At the Arctic Circle and Antarctic Circle imaginary lines encircling the top and bottom of the world the midnight sun and polar night last just 24 hours each September March December
