Tundra-Climate (According to Koppen: ET climate type)
The arctic tundra's climate is dramatically different than any other of the world's biomes. Winters are long, cold and dark, while the summers experience mild temperatures and 24 hour sunlight.
In the fall, the arctic tundra's sun disappears below the horizon and does not rise for 66 days from mid November to late January. This extended period of darkness occurs because of the earth's tilt. In the winter, the Northern Hemisphere, where the arctic tundra is located, tilts away from the sun. During this time, the tundra's temperatures can plunge to a frigid 70ºC(94ºF). Strong winds rip through the tundra also bringing down temperatures with the wind chill factor . For six months or longer the arctic tundra remains covered in ice, seemingly lifeless.
In the winter, the arctic tundra seems inhabitable. Life is no where to be found. However, during the spring and summer seasons, the tundra is flourishing with life. This is because during the spring equinox, the Northern Hemisphere is bathed in constant sun light. For 84 days, from late May to early August, the tundra sun never sets. This is because the arctic regions of the earth are tilted toward the sun, just opposite of what happens in the winter when the arctic regions are tilted away from the sun. With this continuous sun, the ice from the winter season begins to melt quickly. During the spring and summer seasons animals are always active, and plants begin to grow rapidly. The growing season for the tundra is relatively short; lasting six to ten weeks. Comfortable temperatures, sometimes reaching 30ºC(85ºF), also last for a short time. The occasional winds and summer snow storms have a tendency to interrupt any agreeable weather from lasting to long.
In the Southern Hemisphere or Antarctica, where arctic tundra is also located, the seasons are reversed. The earths tilt is once again the reason for this. While the Northern Hemisphere is experiencing 24 hours of darkness, the Southern Hemisphere is experiencing 24 hours of light. The land and climate in these separate hemispheres are affected the same, just at different times of the year.
The alpine tundra shares the same characteristics as the arctic tundra, and is directly related. However alpine tundra is widely scattered and resides in other places besides the arctic regions of the earth. Alpine tundra, like arctic tundra has an extreme climate which includes frigid temperatures, snow storms, blizzards, and gale force winds . Cold temperatures and thin soils make it possible for arctic tundra plant and animal species to thrive in the alpine tundra. The alpine tundra gets more rain than the arctic tundra. However like the arctic tundra's soil, rain runs off rather than collecting in the soil, making the ground very dry. Because of the dry soil, alpine tundra's plants and animals have to endure environmentally devastating mud slides, rock slides, and avalanches in the winter. Alpine tundra animals also have to be specially adapted to strong UV light. This is because the atmosphere at higher altitudes is thinner, allowing more UV light to hit higher forms of land. An example of alpine tundra is the area above the tree line on Humphrey's Peak. Humphrey's Peak located near Flagstaff Arizona, is the highest summit of the San Francisco
Peaks, occurring at 11,000 to 11,400 feet (3353 to 3475 meters). The peaks receive from 33 to 40 inches (76 to 102 centimeters)of rain annually and are covered with snow from late November to early April.