Description

Sea ice is simply ocean water that has frozen. At least 15% of the ocean is covered by sea ice some part of the year. This means that on average, sea ice covers almost 10 million square miles (about 25 million square kilometers) of the Earth. Sea ice concentrations are monitored closely by scientists because changing sea ice concentrations can have a huge impact on the rest of the globe. Global warming is amplified in polar regions. Because of this, monitoring changes in sea ice can be a good indicator of climate change. The National Snow and Ice Data Center monitors sea ice concentrations using a satellite data record that begins in 1978. The Special Sensor Microwave/Imager (SSM/I) is the current monitoring instrument. The sea ice concentration dataset is on a 25km cell size grid covering both Arctic and Antarctic polar regions.

There are three different sea ice concentration datasets available for Science On a Sphere. This dataset shows sea ice concentration every ten days from 1987 - 2010. Also available is a dataset showing Sea ice concentration for every six days from 2005 - 2007. These datasets show the growth and decay of sea ice concentration throughout the year. In the Arctic, the maximum coverage occurs in March and the minimum coverage occurs in September usually. The opposite is true for Antarctic, where the minimum occurs in March and the maximum occurs in September. An interesting point to note in the long dataset is that the extent of sea ice in the Arctic is shrinking, while the Antarctic sea ice is not trending downward. Lastly, a dataset is available that shows only Septembers from 1987 - 2010. September was chosen to highlight the change in the Arctic minimum sea ice concentration through time. The decrease in sea ice coverage is apparent in this dataset.

Notable Features

• Seasonal change of sea ice
• Shrinking of Artic sea ice concentration, especially in summers
• The disappearancee of the Odden, a thumb-shaped sea ice feature east of Greenland, which often is visible prior to the late 1990's
• The minimum sea ice concentration in 2007 shattered the previous minimum sea ice record set in 2005 by 23% and contained 39% less ice than the 1979 to 2000 average.

Related Datasets