Arctic cyclones more common than previously thought

December 11, 2013

SAN FRANCISCO--From 2000 to 2010, about 1,900 cyclones churned across the top of the world each year, leaving warm water and air in their wakes--and melting sea ice in the Arctic Ocean.

That's about 40 percent more than previously thought, according to a new analysis of these Arctic storms.

A 40 percent difference in the number of cyclones could be important to anyone who lives north of 55 degrees latitude--the area of the study, which includes the northern reaches of Canada, Scandinavia and Russia, along with the state of Alaska.

The finding is also important to researchers who want to get a clear picture of current weather patterns, and a better understanding of potential climate change in the future, explained David Bromwich, professor of geography at The Ohio State University and senior research scientist at the Byrd Polar Research Center.

The study was presented Thursday, Dec. 12 at the American Geophysical Union meeting, in a poster co-authored by his colleagues Natalia Tilinina and Sergey Gulev of the Russian Academy of Sciences and Moscow State University.

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

Cyclones are zones of low atmospheric pressure that have wind circulating around them. They can form over land or water, and go by different names depending on their size and where they are located. In Columbus, Ohio, for instance, a low-pressure system in December would simply be called a winter storm. Extreme low-pressure systems formed in the tropical waters can be called hurricanes or typhoons.

How could anyone miss a storm as big as a cyclone? You might think they are easy to detect, but as it turns out, many of the cyclones that were missed were small in size and short in duration, or occurred in unpopulated areas. Yet researchers need to know about all the storms that have occurred if they are to get a complete picture of storm trends in the region.

"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.

Bromwich leads the Arctic System Reanalysis (ASR) collaboration, which uses statistics and computer algorithms to combine and re-examine diverse sources of historical weather information, such as satellite imagery, weather balloons, buoys and weather stations on the ground.

"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.

The actual computations happen at the Ohio Supercomputer Center, and the combined ASR data are made publicly available to scientists.

Two such scientists are cyclone experts Tilinina and Gulev, who worked with Bromwich to look for evidence of telltale changes in wind direction and air pressure in the ASR data. They compared the results to three other data re-analysis groups, all of which combine global weather data.

"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.

One global data set used for comparison was ERA-Interim, which is generated by the European Centre for Medium-Range Weather Forecasts. Focusing on ERA-Interim data for latitudes north of 55 degrees, Tilinina and Gulev identified more than 1,200 cyclones per year between 2000 and 2010. For the same time period, ASR data yielded more than 1,900 cyclones per year.

When they narrowed their search to cyclones that occurred directly over the Arctic Ocean, they found more than 200 per year in ERA-Interim, and a little over 300 per year in ASR.

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 ASR data also provided more detail on the biggest cyclones, capturing the very beginning of the storms earlier and tracking their decay longer.

Extreme Arctic cyclones are of special concern to climate scientists because they melt sea ice, Bromwich 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. 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."

As an example, he cited the especially large cyclone that hit the Arctic in August 2012, which scientists believe played a significant role in the record retreat of sea ice that year.
-end-
ASR is a collaboration among Ohio State, the National Center for Atmospheric Research, the University of Illinois at Urbana-Champaign and the University of Colorado-Boulder. It is funded by the National Science Foundation as an International Polar Year project.

Poster A43C-0280, "Storm tracks in Arctic System Reanalysis - New View of Polar Cyclone Activity," will be presented on Thursday, Dec. 12 from 1:40-6:00 p.m. PT in Hall A-C of Moscone South.

Contact:

David Bromwich
(614) 292-6692
Bromwich.1@osu.edu

Written by Pam Frost Gorder
(614) 292-9475
Gorder.1@osu.edu

Editor's note: To reach Bromwich, Tilinina or Gulev during the AGU conference, contact Pam Frost Gorder.

Ohio State University

Related Sea Ice Articles from Brightsurf:

2020 Arctic sea ice minimum at second lowest on record
NASA and the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder shows that the 2020 minimum extent, which was likely reached on Sept.

Sea ice triggered the Little Ice Age, finds a new study
A new study finds a trigger for the Little Ice Age that cooled Europe from the 1300s through mid-1800s, and supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing.

How much will polar ice sheets add to sea level rise?
Over 99% of terrestrial ice is bound up in the ice sheets covering Antarctic and Greenland.

A snapshot of melting Arctic sea ice during the summer of 2018
A study appearing July 29 in the journal Heliyon details the changes that occurred in the Arctic in September of 2018, a year when nearly 10 million kilometers of sea ice were lost throughout the summer.

Antarctic penguins happier with less sea ice
Researchers have been surprised to find that Adélie penguins in Antarctica prefer reduced sea-ice conditions, not just a little bit, but a lot.

Seasonal sea ice changes hold clues to controlling CO2 levels, ancient ice shows
New research has shed light on the role sea ice plays in managing atmospheric carbon dioxide levels.

Artificial intelligence could revolutionize sea ice warnings
Today, large resources are used to provide vessels in the polar seas with warnings about the spread of sea ice.

Antarctic sea ice loss explained in new study
Scientists have discovered that the summer sea ice in the Weddell Sea sector of Antarctica has decreased by one million square kilometres -- an area twice the size of Spain -- in the last five years, with implications for the marine ecosystem.

Antarctic sea-ice models improve for the next IPCC report
All the new coupled climate models project that the area of sea ice around Antarctica will decline by 2100, but the amount of loss varies considerably between the emissions scenarios.

Earth's glacial cycles enhanced by Antarctic sea-ice
A 784,000 year climate simulation suggests that Southern Ocean sea ice significantly reduces deep ocean ventilation to the atmosphere during glacial periods by reducing both atmospheric exposure of surface waters and vertical mixing of deep ocean waters; in a global carbon cycle model, these effects led to a 40 ppm reduction in atmospheric CO2 during glacial periods relative to pre-industrial level, suggesting how sea ice can drive carbon sequestration early within a glacial cycle.

Read More: Sea Ice News and Sea Ice Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.