Narwhals reveal Atlantic heat penetrating Greenland's fjords

Researchers using narwhals equipped with sensors have discovered warm, salty Atlantic water penetrating deep into the fjords of East Greenland. The study, published in Science Advances, utilized data from six narwhals fitted with sensors that measured temperature, salinity, and depth between 2017 and 2020.

The findings reveal a hidden pathway through which ocean heat reaches glacier fronts, potentially accelerating underwater melting. This process is difficult for human researchers to monitor because the thick sea ice in regions like Scoresby Sound makes navigation by research vessels nearly impossible for much of the year.

Marine biologist Mads Peter Heide-Jørgensen of the Greenland Institute of Natural Resources noted that the sensors detected traces of Atlantic water as far as 300 kilometers from the coast, an observation that provides new insights into how fossil fuel-driven warming is affecting the Greenland ice sheet.