Animation from the Goddard Space Flight Center, Yearly Arctic Sea Ice Age: 1984-2016
One significant change in the Arctic region in recent years has been the rapid decline in perennial sea ice. Perennial sea ice, also known as multi-year ice, is the portion of the sea ice that survives the summer melt season. Perennial ice may have a life-span of nine years or more and represents the thickest component of the sea ice; perennial ice can grow up to 4 meters thick. By contrast, first year ice that grows during a single winter is generally at most 2 meters thick.
This animation shows the Arctic sea ice age for the week of the minimum ice extent for each year, depicting the age in different colors. Younger sea ice, or first-year ice, is shown in a dark shade of blue while the ice that is 5 or more years old is shown as white. A color scale identifies the age of the intermediary years. A bar graph displayed in the lower right corner quantifies the area covered by the ice in each age category on the day of the annual minimum. In addition, memory bars shown in green portray the maximum annual value for each age range seen since Jan. 1, 1984, on the day of the annual minimum.
Editor’s note: This visualization incorrectly identifies the oldest ice as being 5+ years old, when it would be more accurate to say 4+ years old. An updated version of this visualization can be downloaded in HD here: svs.gsfc.nasa.gov
Credit: NASA’s Goddard Space Flight Center/Cindy Starr, visualizer
Dirk Notz at the Max Planck Institute for Meteorology in Germany and Julienne Stroeve at the US National Snow and Ice Data Centre tracked Arctic sea ice extent and anthropogenic carbon emissions over three decades. Writing in Science, they calculated for every metric tonne of carbon dioxide emitted, three square metres of sea ice were lost.
In other words, if you take a one-way flight from Sydney to London, that’s five square metres gone.
While Antarctic sea ice has never been healthier, it’s a different story around the north pole. Arctic sea ice extends in winter and shrinks in summer, but the area it covers has been contracting.
This has far-reaching consequences, including habitat loss, accelerated warming of the region and possible flow-on effects on global weather patterns.
So just how long until an Arctic summer has no sea ice at all? It depends on which climate scientist you ask. While some models suggest sea ice will remain year-round in the Arctic into the next century, others predict the Arctic could be void of summer sea ice in a matter of decades.