An Arctic hurricane?

This satellite image from November 8 shows the hurricane-like storm that hit Western Alaska earlier this month. Credit: NASA Earth Observatory image created by Jesse Allen, using data obtained from the Land Atmosphere Near real-time Capability for EOS (LANCE).

On November 8 and 9, a strong storm hit the Western Alaska coast, bringing blizzard conditions, storm surge of up to 10 feet and wind gusts as fast as 93 miles per hour. Along the Western Alaskan coastline, towns and villages prepared for the worst. “Up here, cities are much more sparse, but a storm like this still impacts the people that live there,” said Kathleen Cole, an ice forecaster at the National Weather Service. Damage reports after the storm indicated extensive flooding, wind damage to buildings, as well as power outages, which led to many evacuations to higher ground and to shelters with generator power. Some reports referred to the storm as a “blizzicane,” or an Arctic hurricane. What was unusual about this storm—and was there any connection to changes in the Arctic climate? Continue reading

What’s in a number? Arctic sea ice and record lows

Arctic sea ice extent for September, 2011 was the second-lowest in the satellite record. However, other data sources showed that ice extent perhaps hit a new record low for several days in September. Credit: NSIDC/NASA Earth Observatory

Did Arctic sea ice reach an all-time record low this year—or not? Scientists at University of Bremen in Germany thought it was a new record, while data from NSIDC showed the sea ice at its second-lowest level. The two groups were examining data from two different satellite sensors. Why did the data differ—and if data can vary, does a record low really matter? Continue reading