December 12, 2013
Arctic Cyclones 40 Percent More Active Than Previously Believed
redOrbit Staff & Wire Reports - Your Universe Online
Approximately 1,900 Arctic cyclones occurred between 2000 and 2010 – 40 percent more than previously thought, according to research presented Thursday at the 2013 fall meeting of the American Geophysical Union in San Francisco, California.
The discovery that these storms are more common than previously believed could be important to those living anywhere in the region north of 55 degrees latitude, including the northern parts of Canada, Scandinavia, Russia and Alaska, explained David Bromwich, a geography professor at the Ohio State University and a senior research scientist at the Byrd Polar Research Center, and his colleagues.
Furthermore, the research will prove essential to climate scientists attempting to get a better understanding of current weather patterns, as well as insight into potential future climate change, Bromwich said. Bromwich and co-authors Natalia Tilinina and Sergey Gulev of the Russian Academy of Sciences and Moscow State University attributed the discovery to improved cyclone detection methods.
Cyclones, which are low atmospheric pressure zones that have wind circulating around them, can form over either land or water, and can also be called winter storms, hurricanes or typhoons based on where they form. While it might seem as though the storms should be easy to detect, the study authors said that many of the ones previously missed by researchers were relatively small in size, short in duration, or took place in unpopulated areas.
“We can't yet tell if the number of cyclones is increasing or decreasing, because that would take a multi-decade 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,” said Bromwich, who heads up a collaboration known as the Arctic System Reanalysis (ASR) that utilizes statistics and computer algorithms to re-examine historical weather information.
“There is actually so much information, it's hard to know what to do with it all,” he added. “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.”
The ASR team’s computations occur at the Ohio Supercomputer Center, and the information is made available to scientists such as Tilinina and Gulev – cyclone experts who teamed up with Bromwich in order to find evidence of wind direction and air pressure changes in the data. They compared the study’s findings to data from three other analysis groups, all of which combined global weather data, the researchers explained.
“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.
Tilinina and Gulev looked at ERA-Interim data generated by the European Centre for Medium-Range Weather Forecasts for areas north of 55 degrees, revealing over 1,200 cyclones per year from 2000 through 2010. Over the same 10-year time period, the ASR data revealed 700 additional cyclones – a total of 1,900 cyclones per year. Narrowing their search to those occurring directly over the Arctic Ocean, the ERA-Interim data showed over 200 per year versus slightly more than 300 per year for the ASR data.
“There was good agreement between all the data sets when it came to big cyclones, the researchers found, but the Arctic-centered ASR appeared to catch smaller, shorter-lived cyclones that escaped detection in the larger, global data sets,” the university said. “The ASR data also provided more detail on the biggest cyclones, capturing the very beginning of the storms earlier and tracking their decay longer.”