This natural cycle of freezing and thawing is influenced both by seasonal temperature variations and long-term climate change. Scientists are using satellite images to measure the distribution of Arctic sea ice in order to gain a better understanding of how it is linked to Earth’s climate system.

Over the past few decades, the amount of sea ice in the Arctic has gradually been dwindling. While the white Arctic ice reflects the Sun’s rays back into the upper atmosphere, the surrounding water absorbs heat and increases in temperature. The warmer water continues to melt more ice, decreasing the amount of solar energy that can be reflected and increasing energy absorbed by the water. This effect, called a positive feedback loop, contributes to a trend towards warmer global temperatures.

This video illustrates both seasonal patterns and long-term changes in sea ice distribution across the Arctic Ocean. It draws data from two satellite instruments that measure emitted microwave radiation, which helps distinguish open ocean from ice. The Scanning Multichannel Microwave Radiometer recorded data on sea ice conditions from October 1978 through August 1987. The Special Sensor Microwave Imager has provided data since June 1987.

Special thanks to the National Snow and Ice Data Center to Claire Parkinson & Nick DiGirolamo of the NASA Goddard Space Flight Center Hydrospheric and Biospheric Sciences Laboratory .