A polar ice cap is a high-latitude region (60-90°N & S)of a planet or moon that is covered in ice. Polar ice caps do not have size, composition or geologic requirements of being over land, but they must be centered in the polar region, aka the axis of rotation.In the geologic time scale, the ice caps may grow or shrink due to climate variation, and the poles have even apparently migrated!

Earth's south pole, on the continent of Antarctica, is covered by the Antarctic ice sheet. It covers an area of almost 14 million km². Around 90% of the fresh water on the Earth's surface is held in this ice sheet.

Vostok, Antarctica holds the world's record for coldest temperature ever recorded on Earth:

-129°F (7/21/83).

Despite the hostile environment, the short growing season is long enough to support low-growing plants

-136°F in 8/10/10 NASA Unofficial

Today, Earth's north pole is covered by floating pack ice (sea ice) over the Arctic Ocean. There is no land mass at that pole.Portions of the ice that don't melt seasonally can get very thick, up to 3–4 meters thick over large areas, with ridges up to 20 meters thick. The area covered by sea ice ranges between 9 and 12 million km².

Abiotic Data:Latitude: from 66.5°- 90° south, and north Soil Moisture: dry Soil Organic Content: lowSunlight: bright 24/7 in the summer, dark 24/7 in the winterWind: strong winds Summer temperature: north: 29 °F, south:-25 °FWinter temperatures: north: -40°F, south: -60°FColdest temperature ever recorded in the northern hemisphere: Verkhoyansk, Siberia (-94º F)

The sun rises at the north pole on the spring equinox.It gets higher in the sky every day, until the summer solstice.Then the sun begins its long journey setting in the sky towards the west.The sun sets on the fall equinox, and there is darkness from October until the next spring, in March, when it rises again.If days were measured in darkness and daylight, instead of hours, there would only be one day every year at the north pole.The reverse of this happens in the southern hemisphere.

Things you should know:Things you should know:

Where is most of Earth’s freshwater found?

What is the biggest difference between the N.P. region, and the S.P. region (besides direction!)?

Why is soil organic content so low in Antarctica?

Why would the S.P. (a typically colder region) support low-growing plants, but not the N.P.?

• Tundra is a vast treeless land•Too cold for trees to grow

•Permafrost layer •Dark during winter

•Soggy during summer•World’s youngest biome

•Mostly in Northern HemisphereParts of Alaska, Northern Canada, Greenland, and parts of RussiaTundra covers one fifth of the Earth's surface and comes from the Finnish word tunturia and means barren or treeless land.

There are two seasons in the TundraWinter and summer

A typical Tundra climograph might look something like thisOn a climograph, the temperature data is always a line graph, while the precipitation is shown in a bar graph.

Temperature: -18°FCan get to 54° F in the summer, and as cold as -94° F in the winter

Because of its location within the arctic circle, the sun shines almost 24 hours in summer. The winter is almost completely dark 24 hours a day.

Precipitation: desert-like, 6-10” per year… mostly snow

There is a low biodiversity of flora, as well as fauna on the tundra.Musk oxen, reindeer and polar bears, and snowshoe hares are among the largest grazers found.Even though it gets swampy, there are very few reptiles and amphibians found in the tundra because the temperatures are so cold.

Many animals that live in the tundra, like the caribou and the, musk ox migrate to warmer climates during the winter. Others, like the arctic ground squirrel, hibernate during the winter months.

Arctic wolves simply tough it out, and grow a winter coat of fur to help insulate them from the cold.

The ermine is a type of tundra weasel. In the summer months, it has a chocolate brown fur.In the winter its fur turns snow-white.

It is a predator, so it uses its camouflage to help it hunt in the hostile environment.

The growing season in the tundra is very short, usually only 6 to 10 weeks.

As the top layer of soil thaws out, plants and microorganisms have a chance to grow and reproduce. Since the sun is out for most of the time, the plants have extra sunlight and can grow faster.

Flora grow shorter, with densely matted shallow root systems. This protects them from the freezing drying winds constantly blowing over the tundra.

Colorful angiosperms use this short growing season to their advantage, and multiply quickly during the 24 hours of daylight.

In the summer, the top layer of soil may thaw out. When the ice melts, it can't drain into the soil because of the permafrost, so water collects in bogs and ponds. Cushion plants such as lichens and mosses, grow in the tundra, and are types of plants that grow low to the ground in tight places. They are called cushion plants because they are soft and cushiony.

The bearberry is a short shrub, protected from the cold winds by “hairy leaves and stems”…which have a fuzzy appearance.

The Tundra is one of the most fragile environments. Because of its desert-like lack of precipitation, a footprint can remain frozen in the

soil for years virtually unchanged.

Another fact that makes the Tundra extremely fragile, is its low biodiversity.

The extremely cold temperatures makes the tundra a difficult environment to survive in during the winter, and plants and animals have a hard time coping with any extra stresses and disturbances created by humans.

and eventually the ruts turn into gullies. Tracks made during WW II have grown so large that some of them are now lakes.

• Pesticides have been used to control the hordes of insects. Thousands of migrating birds come to the tundra because of the abundant insects. Through the food chain the pesticides reach many of the animals that live on the tundra.

• Just like the footprints, ruts from jeeps and tanks made during WWII turn into gullies. Some have grown so large that they are now lakes, altering the ecosystem.

• Pollution from mining and drilling for oil has polluted the air, lakes and rivers. The land around some nickel mines in Russia has become so polluted that the plants in the surrounding area have died..

Biological Magnification

Why are there no trees on the Tundra?

It is also cold and treeless in Antarctica. Why isn’t it a true Tundra?

Name and describe two ways that flora have adapted to the Tundra.

Name and describe two ways that fauna have adapted to the Tundra.

Why is the Tundra particularly fragile?

Describe how humans have proven hazardous to the Tundra.