Climate Models Overlook a Natural Cloud-Making Engine
An international team led by the University of Birmingham has identified a previously overlooked mechanism that can drive up Arctic atmospheric particle concentrations by a factor of 50 in a single day. It operates in the narrow zone where melting sea ice gives way to open water. The findings come from observations made near Greenland and in Davis Strait aboard the research vessel Discovery during spring and summer 2022.
Sunlight triggers chemical reactions among substances released into the air from the ocean, sea ice, and living organisms. In one measurement, particle counts climbed from roughly 50 to about 1,500 per cubic centimeter over the course of a day.
What Drives the Particle Formation
The process involves a combination of:
- iodine compounds;
- dimethyl sulfide emitted by marine plants and algae;
- organic compounds originating both at sea and on land.
The researchers also uncovered a previously unknown group of atmospheric substances: iodine-containing oxygenated organic molecules. New particles formed on more than 80 percent of sunny days during the observation period. Researcher James Breen commented:
"No one had observed this atmospheric-chemistry pathway in the real Arctic before; it had only been demonstrated in CERN's laboratory," said Breen.
Even so, the mechanism is not yet included in climate models, and the team intends to add it to future simulations.
These expedition results could significantly refine how Arctic atmospheric processes are understood and how climate models are constructed. Since the Arctic is warming faster than most of the planet, capturing such natural drivers is vital for improving climate projections. The discovery highlights why natural pathways that shape clouds and particles must be accounted for in a changing climate.
Understanding the mechanisms driving Arctic cloud formation is crucial, especially as the implications of climate change unfold. In a related context, recent studies indicate that the Atlantic Ocean's circulation may face a tipping point if global temperatures rise too swiftly. To explore how these interconnected systems could influence climate dynamics, see more about the potential collapse of Atlantic currents here.