Hurricanes threaten the North American coast every year, and they’re apparently getting worse with climate change. Similar storms can hit colder regions in the far north, and new research suggests they will intensify as well. Results published on Nov. Nature CommunicationNASA scientists predict that spring Arctic cyclones will intensify by the end of this century, due to sea ice loss and rapidly rising temperatures. These conditions will lead to stronger storms that will bring warmer air and more humidity to the Arctic.

“Cyclones will be much stronger in terms of pressure, wind speed and precipitation,” said Dr Chelsea Parker, who led the study. “Initially, storms will bring more snow, but as temperatures continue to rise and rise above freezing, storms will reduce precipitation, which is a really big change for sea ice.” Parker is a research fellow at the University of Maryland and NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“More intense storms pose threats to shipping, oil and gas drilling and production, fisheries, Arctic ecosystems and biodiversity – this is where marine weather forecasting is important but still complex and challenging,” Parker said. “It’s an interesting push and pull, because when the sea ice recedes, it opens up more room for these events, but it can also lead to more dangerous weather.” The maps above show simulated storm tracks and wind speeds for the nine Arctic cyclones. The image on the left shows simulated storm tracks as it hit the North Pole over the past decade. The image on the right shows how cyclones will respond to climate change by the end of the century. Credit: Using data from NASA Earth Observatory/Joshua Stevens, Parker, CL et al.

Parker and colleagues analyzed computer simulations of nine cyclones that have hit the Arctic over the past decade. The warming and loss of sea ice in recent decades has not had a noticeable effect on the behavior of these spring storms, Parker said.

To better understand future conditions, the scientists used the results of paired model comparison projects to model an Arctic with higher temperatures and less sea ice cover. “When we add predicted future climate change to computer simulations, we see a really big hurricane response,” Parker said.

The team found that by the end of the century, the cyclone’s wind speed could reach 38 mph, depending on the storm’s characteristics and the area’s environmental conditions. Parker noted that peak intensity of such storms could last up to 30% longer, with precipitation likely to increase. If cyclones begin to bring precipitation in the spring, the sea ice may begin to melt sooner, and fewer may survive the summer melt season.

Such changes would allow the ocean to provide more energy to the atmosphere for deep convection, increasing the potential for storms to intensify and persist. Like low and mid-latitude hurricanes, polar cyclones use this energy as fuel for their engines. Storms in the coming decades may spread further north and reach normally untouched areas of the Arctic. Changing weather can increase risks to Arctic ecosystems, communities, and commercial and industrial activities. July 28, 2020 An Arctic hurricane swirling over the Arctic Ocean. Arctic cyclones can cause sea ice to melt faster. Its strong winds can break and agitate the ice and lift warmer waters that would otherwise be covered in ice. Depending on their location, temperature, and whether these storms produce snow or rain, they can also cause ice to freeze or melt faster. Image obtained by the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Terra and Aqua satellites. Credit: NASA Earth Observatory

To give their model a real-world basis, Parker and colleagues compared their model simulations with direct observations of several Arctic storms collected in 2020 by the international MOSAiC expedition. Combining case studies of recent storms with high-resolution climate simulations, the new study is one of the first to show the direct response of cyclones to recent and future climate change.

“We don’t usually have a lot of weather station data from the Arctic to do this, so MOSAiC was an important piece for us because we were able to use actual measurements to validate our model,” Parker said. “We can say that our current climate modeling of these cyclones is realistic and we can trust what the model is doing.”

Observations from space and on the ground have shown that the Arctic is warming almost four times faster than the rest of the planet. Scientists need more information about Arctic cyclones to make more accurate predictions about how storms will affect the already shrinking sea ice and how ice loss will affect storm intensity. A better understanding of these interactions will help scientists study how rapid warming will affect the planet. Source