In a Decade, Arctic Saw 40 Percent More Cyclones Than Previously Believed

In the decade between 2000 and 2010 about 1,900 cyclones churned through the Arctic, scientists report, noting that total to be about 40 percent more than previously believed.

While it may be easy to jump to conclusions about global climate change playing a role in the increase, these high-latitude cyclones have increased largely because scientists have gotten better at detecting them, according to David Bromwich, a geography professor at The Ohio State University, who presented the research this week in San Francisco at the 46th Annual Fall Meeting of the American Geophysical Union.

These "new" cyclones were generally smaller, of shorter duration and occurred in unpopulated areas, which made them more difficult to detect. But as the technology to detect these low-pressure systems improves, it becomes easier for scientists to spot them.

"We now know there were more cyclones than previously thought, simply because we've gotten better at detecting them," Bromwich said.

Studying these smaller storms will help researchers gain a better understanding of overall storm trends in the Arctic.

"We can't yet tell if the number of cyclones is increasing or decreasing, because that would take a multidecade view. We do know that, since 2000, there have been a lot of rapid changes in the Arctic-Greenland ice melting, tundra thawing-so we can say that we're capturing a good view of what's happening in the Arctic during the current time of rapid changes," Bromwich said.

The Arctic System Reanalysis (ASR) collaboration, led by Bromwich, takes existing weather data from the Arctic and reanalyzes for previously overlooked items. The ASR handles such great volumes of data it requires supercomputers to operate.

"There is actually so much information, it's hard to know what to do with it all. Each piece of data tells a different part of the story-temperature, air pressure, wind, precipitation-and we try to take all of these data and blend them together in a coherent way," Bromwich said.

Bromwich's colleague Natalia Tilinina of the Russian Academy of Sciences spoke to the utility the ASR data provided to her research.

"We found that ASR provides new vision of the cyclone activity in high latitudes, showing that the Arctic is much more densely populated with cyclones than was suggested by the global re-analyses," Tilinina said.

These Arctic cyclones could play a role in the climate change by acting as a catalyst for melting ice, the researchers said.

"When a cyclone goes over water, it mixes the water up. In the tropical latitudes, surface water is warm, and hurricanes churn cold water from the deep up to the surface," Bromwich said. "In the Arctic, it's the exact opposite: there's warmer water below, and the cyclone churns that warm water up to the surface, so the ice melts."