A Frigid Current and a Heroic Expedition

A decade ago, oceanographers discovered a deep current flowing along the west coast of Iceland. It supplies the coldest and densest water to the North Atlantic as part of the ocean’s overturning circulation—the global “conveyor belt” for seawater. This system plays a major role in regulating our climate by moving heat around the planet. Without it, most life would perish. We therefore need to understand this current and how it may be changing as the region warms rapidly.

But no one yet knows where or how it forms.

This winter, a remarkable field expedition will try to answer that question. A team of oceanographers and atmospheric scientists will test whether the dense water is formed when winter storms draw bitter cold air off the Greenland pack ice onto the ocean, cooling down the surface water and causing it to sink. The only way to do this is to take a ship and plane into some of the worst weather on Earth—the heart of these winter storms east of Greenland. The plane will fly harrowingly close to the ocean’s surface with air-sampling sensors strapped to its exterior. The ship will be pushed into punishing seas to sample the water off the ice edge.

Reporter Ari Daniel joins the expedition—a scientific quest for answers that could be key to understanding our changing climate.