when we talk about the Arctic, we all think of the polar bear. What are the characteristics of the Arctic? What are the reasons for the formation of the Arctic climate?
The Arctic winter lasts for six months from November to April of the following year. 5. June, September and October belong to spring and autumn. In summer, it's only 7 or 8 months. The average temperature in January is - 20-40 ℃. The average temperature in August of the warmest month is only - 8 ℃. The lowest temperature measured at the drifting station near the pole of the Arctic Ocean is - 59 ℃. Due to the influence of ocean current and Arctic anticyclone, the coldest place in the Arctic is not in the central Arctic Ocean. The lowest temperature of - 70 ℃ was recorded in verhojansk, Siberia, and - 62 ℃ in Prospekt, Alaska.
The southern boundary of sea ice is not fixed. With the change of hydrological and meteorological conditions, it can often change hundreds of kilometers. Under the action of wind and current, floating ice can accumulate and form a huge floating iceberg. The vast majority of icebergs commonly seen refer to huge ice bodies with a diameter greater than 5 meters falling from the continental shelf or ice sheet. The thickness of large table icebergs can reach 200-300 meters, and the average life span is up to 4 years. If you are lucky, you can also see a huge iceberg, tens of kilometers long, like a piece of white land across the dark gray sea.
The floating icebergs formed by sea ice in the Arctic Ocean, together with the icebergs formed by glaciers and ice shelves from Greenland and other islands, enter the Atlantic Ocean or the sea off Alaska with the current, and some icebergs can drift southward to 40 & deg; n;. In 1912, the world's most luxurious passenger ship, Titanic, hit an iceberg floating out of the Arctic Ocean and sank on its first voyage, resulting in the world's famous "ice sea sinking" tragedy.
Current in the Arctic:
The Arctic belongs to the world of ice and snow, but due to the movement of ocean currents, the sea ice on the surface of the Arctic Ocean is constantly drifting, cracking and melting, so it is impossible to accumulate thousands of kilometers of ice and snow in millions of years like the Antarctic continent. Therefore, the total amount of ice and snow in the Arctic is only close to 1 / 10 of the Antarctic, most of which are concentrated in the continental ice sheet of Greenland, while the permanent ice and snow in the Arctic Ocean, other islands and surrounding land only account for a small part.
Most of the surface of the Arctic Ocean is covered with sea ice all the year round. It is the only white ocean on the earth. The average thickness of Arctic sea ice is 3 meters, covering 73% of the total ocean area in winter, about 10-11 million square kilometers, 53% in summer, about 7.5-8 million square kilometers. The sea ice in the central Arctic Ocean has existed for 3 million years and belongs to permanent sea ice.