Narwhals are helping scientists visit a place no boat can go

Professor Pip zipped up his fuzzy scarf and clambered onto a little wooden boat, his forest-green lab coat flapping in the polar wind. The fjord stretched out around him — icy blue water, snowy peaks, and pale chunks of ice bobbing like marshmallows.

"Brrrrrr! Oh my whiskers, it's cold," he said, his breath puffing.

Mia and Leo, bundled in coats and mittens, knelt beside him at the rail. "Where are we, Professor?" Leo asked.

"East Greenland!" Pip announced, pulling a tiny brass telescope from a pocket. "And today we have a very important question: how warm is the water way down deep?"

"Can't you just… put a thermometer in?" asked Mia.

"Ah, a fine idea!" said Pip. "Except the deep water here is nearly a mile down. And covered in ice. And full of icebergs that could crunch a boat like a cookie." He shivered dramatically. "So we need a helper who can dive deeper than any submarine and swim around ice we can't reach."

SPLOOSH! Right beside the boat, a long spiral tusk broke the surface, followed by a gray-and-white speckled head with dark, curious eyes.

"A narwhal!" Mia squealed.

"Precisely!" Pip beamed. "Narwhals are whales with a long spiraled tooth like a unicorn's horn. They live where we can't. And they dive a whole kilometer down, over and over, all winter long."

He held up a tiny gadget with a little antenna. "Scientists gently attached little sensors like this to six narwhal friends. Every time a narwhal dove, the sensor measured the temperature and saltiness of the water — and beamed the numbers up to a satellite in space."

"So the narwhals are… scientists?" Leo asked, grinning.

"They most certainly are. Two thousand and sixty dives! And they discovered something surprising: warm water from way down south is sneaking up under the ice, deeper than anyone knew."

He blew on his tea; the steam rose off it in curls. "See how the warm steam floats up? Cold water sinks and warm water rises — but salty water is heavy, so warm salty water can slip underneath cold fresh water. That's the sneaky part. It touches the glaciers from below and melts them."

Leo's mouth fell open. "Whoa. That's like ice cream melting from the bottom."

"Exactly right!" Pip laughed. "This is oceanography — the science of understanding how oceans work. And sometimes, the best way to understand a place is to ask the animals who already live there."

The narwhal blew a tiny mist from its blowhole and slid back into the deep. Pip tipped his hat.

"Thank you, friend."