Arctic sea ice is near its annual low extent for the year. Will it reach a new record low? While many people are watching this year’s ice extent closely, the effect of climate change on ice extent in a single year is different than its effect in the long term. Arctic sea ice has declined more than 30 percent in summer since satellite measurements started in 1979. But from year to year, ice extent jumps up and down quite a lot. Continue reading
NSIDC reports ice extent, a two-dimensional measure of the Arctic Ocean’s ice cover. But sea ice extent tells only part of the story: sea ice is not all flat like a sheet of paper. While freshly formed ice might not be much thicker than a few sheets of paper, the oldest, thickest ice in the Arctic can be more than 15 feet thick—as thick as a one-story house. Scientists want to know not just how far the ice extends, but also how deep and thick it is, because thinner ice is more vulnerable to summer melt. Continue reading
So far this summer, Arctic sea ice has been melting at a record pace. Satellite data, which go back to 1979, show that ice extent is currently lower than it was at the same time in 2007, the year that went on to shatter all previous records for low ice extent in September, the end of the melt season (Figure 1). It is not yet clear if the ice will hit a new record low this September. But whether or not the ice extent sets another record, Arctic sea ice is continuing its long-term decline, a trend that researchers say is related to warming temperatures in the Arctic.
Average Arctic sea ice extent this May was the third lowest in the satellite record. Does that mean that ice extent will reach a new record low this summer? Or will it recover somewhat over recent years?
Last week sea ice scientists from around the world shared their best answers to those questions, in the June report of the Sea Ice Outlook. For the report, the researchers used a variety of methods to predict how sea ice will behave this summer, such as statistical methods or computer models. Continue reading
Why does it matter if the Arctic sea ice melts? We often hear about the global consequences: waning sea ice is expected to lead to even more climate warming. On a more immediate and local level, the loss of summer sea ice is already affecting the land and people near the Arctic Ocean. As the ice melts to reveal the open ocean underneath, fragile coastlines become vulnerable to bigger waves and storms. Continue reading