AUSTIN (KXAN) — For decades now, sea ice in the Arctic continues to melt as our climate continues to warm from greenhouse gas emissions. As sea ice and snow melt, less solar radiation is being reflected back into space and is instead now absorbed at the surface.
This is called a ‘Positive Feedback Loop’ where warming causes ice to melt and then that melting causes further warming. Because of this, the Arctic is actually warming roughly two times faster than the rest of the globe.
One “benefit” of sea ice loss however has been the increased amount of cargo ships that have been more freely able to sail through the Arctic as shipping channels open. The Trans-Arctic route for example runs from the Atlantic to the Pacific Ocean through the Arctic Ocean. This used to be a nearly impossible route without heavy icebreakers attached to the ships. But now with less and less sea ice, Trans-Arctic shipping has increased, tremendously reducing travel time, increasing shipping time and reducing the overall cost of international trading.
These cargo ships are now facing a new foe: sea fog.
A new study shows as sea ice is rapidly melting in the Arctic, fog is increasingly developing which in return is reducing visibility and creating a dangerous hazard. The lack of visibility increases the likelihood of these ships running into icebergs that they cannot see.
Why is sea fog forming?
The ocean water underneath the sea ice is warmer than the air temperature. As the ice melts and dissipates, this (relatively) warm water is now exposed to colder air above it. The air directly above the warm water cools from the cold air and condenses into fog.
What their study found
Researchers used data on Arctic fog collected from 1979 to 2018 to track the changes over the years. They also used climate models to display best alternate routes for the future that they could use to minimize foggy days during shipping journeys. Here is what they found:
- More than 20% of Arctic shipping routes experience frequent sea fog
- Sea fog increases the shipping time by 23%–27% along the Northwest Passage (Nearly three full days added)
- Sea fog increases the shipping time by 4%–11% along the Northern Sea Route (Nearly one full day added)
- All shipping route lengths could be shortened (from improved visibility) the further you shift away from the closest edge of the Arctic sea ice shelf