This winter’s record low Arctic sea ice
Arctic sea ice plays an important role in maintaining Earth’s temperature—its bright white surface reflects solar energy that the ocean would otherwise absorb. But this effect is more relevant in the summer, when the sun is high in the sky in the Arctic, than in the winter, when the sun doesn’t rise for months within the Arctic Circle. In the winter, the impact of missing sea ice is mostly felt in the atmosphere, said Jennifer Francis, a climate scientist at Rutgers University.
“In places where sea ice has been lost, those areas of open water will put more heat into the atmosphere because the air is much colder than unfrozen sea water,” Francis said. “As winter sea ice disappears, areas of unusually warm air temperatures in the Arctic will expand. These are also areas of increased evaporation, and the resulting water vapor will contribute to increased cloudiness, which in winter, further warms the surface.”