Readers sometimes ask us, “What are the reasons behind Arctic sea ice decline?” In summer months, ice extent has declined by more than 30 percent since the start of satellite observations in 1979. But is climate change really the culprit, or could other factors be contributing? Continue reading
In summer months, icebreaking ships head north into the Arctic Ocean, tearing through the sea ice and leaving trails of open water in their wakes. Readers occasionally write in to ask us whether the trails left by these ships contribute to the melting of sea ice. Continue reading
Last year, many scientists blamed the winter storms that blasted the Northeastern United States and Europe on the negative mode of a weather pattern called the Arctic Oscillation. This winter, the Arctic Oscillation started out in the opposite mode, which scientists connect to the warmer-than-average temperatures and unusually low snowfall over much of the U.S. The swings of the Arctic Oscillation also help control how sea ice moves in the Arctic Ocean, which is of great interest to climate scientists. Readers often write in to ask us about this powerful but mysterious climate phenomenon, and how it affects weather where they live. What is the Arctic Oscillation, and how does it affect Arctic sea ice and the rest of the Northern Hemisphere? 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.
Arctic sea ice has most likely frozen to its maximum extent for the winter. This event marks the turning point between winter and spring for sea ice, and may affect the amount of ice that will remain by end of summer. In early April, NSIDC scientists will talk about what this year’s maximum signifies for the upcoming summer. Meanwhile, readers are asking how the ice cover this year is different from the ice cover in years past.
Arctic sea ice grows each winter, hitting its annual maximum sometime in March. When the sun returns to the Arctic in the spring, the air warms up and the ice starts to melt. The ice retreats through the warmer summer months, hitting its lowest point sometime in September. Although scientists watch the sea ice year-round, they pay attention to the highest and lowest extents of the year as indicators of the overall health of the sea ice. Continue reading