Polynas in the Arctic
A polynya is a large area of open water surrounded by sea ice that is found in the same region year after year. Although polynyas can be hundreds of kilometres wide, their surface area is far less than the area of sea ice which surrounds them. However, the open waters of polynyas are very important to life in the Arctic Ocean. Polynyas teem with animal and plant life. It is only here, where the sea ice is absent, that the sunís energy directly reaches the waters. Snow and ice ordinarily reflect much of the sunís light energy, but the open waters of polynyas absorb it. Phytoplankton in the polynya use this energy to produce a nutrient rich grazing area for zooplankton. Feeding on these small animals are whales and fishes that in turn feed seals, walruses and polar bears. Often seen as oases in the harsh climate of the Arctic marine environment, polynyas have intrigued scientists for more than a century.
How do they form?