FIelDWORK The Unseen Currents On the Labrador Sea, the scientific crew of the research vessel Knorr hunts for underwater storms, sinks a two-mile mooring—and gathers clues to the planet’s fate By Donovan Hohn ILLUSTRATIONS BY CHRIS GALL 68 POPULAR SCIENCE MARCH 2011 POPSCI.COM POPULAR SCIENCE 69 FIelDWORK S WE PASS THROUGH the Strait of Belle Isle and emerge from the shelter of Newfoundland’s lee, the first mate pipes instructions from Athe bridge: Lash down or stow all belongings. Rough weather ahead. Two decks below in the main lab, Amy Bower loads onto her extra-large monitor what appear to be abstract paintings, giant red and orange blobs in a field of yellow, as her computer reads text aloud in a robotic voice. Nose almost touching the screen, she searches for clues in the colorful abstractions, which are in fact oversized topographical maps of the Labrador Sea. A senior scientist at the Woods Hole Oceanographic Institution in Massachusetts, Bower is the chief scientist on the first leg of voyage 192, as it’s officially called—a search for the hidden weather that roils beneath the sea. She also happens to suffer from not one but two congenital diseases: macular degeneration and retinitis pigmentosa. She is legally blind. But in her 22 years as an oceanographer, she’s confronted winter storms on the North Atlantic and Somali pirates in the Gulf of Aden. With the help of her computer and other instruments, Bower can see the ocean far more clearly than most of us. Weather permitting, voyage 192 will take us to transport up to 69 trillion cubic feet of water, along Nuuk, Greenland, just south of Davis Strait. There, at with flora and fauna and flotsam, seaweed and krill. If 60.6°N, 52.4°W, we will deploy a “densely instrumented warmer than the water through which they swirl, as mooring,” a kind of underwater weather vane almost Irminger Rings are, they can also transport a great deal two miles long in waters two miles deep. Then, if of heat. How much heat Irminger Rings transport, no all goes well, Bower will use the mooring to gather one yet knows. That depends how many are out there, intelligence on Irminger Rings, a variety of “mesoscale how long they last, how far they travel and where— eddy” spawned by the Irminger Current, a remnant obscurities Bower hopes her data will illuminate. Of of the Gulf Stream. Mesoscale eddies are underwater one thing, however, she and other oceanographers are storms, submarine cyclones the circling currents of already certain: Irminger Rings exert a profound if which attain a “swirl speed” of around one mile per subtle influence on the weather of the Labrador Sea and hour—the speed, in other words, not of a hurricane therefore of Greenland and therefore of the world. or a gale but of a breeze. You can’t see mesoscale The Labrador Sea isn’t only the birthplace of eddies, or feel them. You could be sailing on calm Irminger Rings. It is also the birthplace of icebergs, 41 seas, at Beaufort-force 0 (“sea like a mirror”), and the of which, according to Canadian ice charts, are now underwater storm of the century could be swirling loose on the Labrador Current. Two seamen begin slowly beneath. Irminger Rings raise a bump on the standing watch instead of one, scanning the horizon ocean’s surface dozens of miles in diameter but just with night-vision goggles. Over the PA system, the first six inches taller than the surrounding water. mate gives the order to shut the lids of all portholes; Mesoscale eddies may seem like the sort of thing night-vision goggles work best in total darkness. One by only a scientist would care about. No one names them, one, the ship’s bright windows wink out. after all, or watches them on the Weather Channel. They’ve never caused a ship to sink or a sailor to drown. N THE LAST CHAPTER of The Sea around Us, Few people outside the world of oceanography have I published in 1950, Rachel Carson writes that the ever heard of them. Nevertheless, they are as much a benighted cartographers of the Middle Ages had cause and effect of the climate as floods and hurricanes. thought of the ocean as the “dread Sea of Darkness.” In their slow-moving coils, mesoscale eddies can Over the centuries, little by little, explorers and 70 POPULar SCIENCE MARCH 2011 “Tie that down! Now hold it fast! Clear it! I said clear it! You! On the winch! Pay it out! Pay it out! Now stop! I said stop!” POPSCI.COM POPULar SCIENCE 71 FIelDWORK “Even with all our modern instruments, no one now can say that we shall ever resolve the last, the ultimate mysteries of the sea.” 72 POPULar SCIENCE MARCH 2011 then scientists had pulled the veil of darkness back. west of Greenland’s continental shelf, he says, but sea “Here and there, in a few out-of-the-way places, the conditions have continued to deteriorate. Clouds of darkness of antiquity still lingers over the surface drizzling rain have lowered around us. The second of the waters,” Carson writes. “But it is rapidly being mate spreads weather maps on a workbench, and we dispelled, and most of the length and breadth of the gather around. The winds right now are blowing 31.5 ocean is known; it is only in thinking of its third knots out of the north—out of the Arctic. Through dimension that we can still apply the concept of the the portholes we can hear them scream. By tomorrow Sea of Darkness. It took centuries to chart the surface morning, the winds will be 40 knots: gale force. In three of the sea; our progress in delineating the unseen days, in Nuuk, the capital of Greenland, the first leg of world beneath it seems by comparison phenomenally voyage 192 is scheduled to end and the second leg to rapid.” Carson didn’t end her story on a triumphant begin. The second leg’s scientific team, flying out from note. Prophetically, she added this: “Even with all our Seattle, is already on its way to meet us. There’s no time modern instruments for probing and sampling the left to wait out the storm. Sheasley’s recommendation: deep ocean, no one now can say that we shall ever we deploy tonight. “You OK with that?” Bower asks resolve the last, the ultimate mysteries of the sea.” deck boss Will Ostrom. Which brings us to mesoscale eddies. Deep crow’s-feet have formed at the corners of In 1959, aboard a ketch called the Aries, an English Ostrom’s eyes, and black crescents of grease have oceanographer named John Swallow sailed northeast collected under his fingernails. His wardrobe consists out of Bermuda into the Sargasso Sea in search of of old blue jeans and old flannel shirts, the sleeves a vast, deep and altogether hypothetical northerly of which are always rolled up. The bosun of another current. Into the water he lowered neutrally buoyant research vessel once drew a caricature of Ostrom floats soldered together from aluminum scrap. Then depicting him as a little devil in a red jumpsuit, pricking he lowered his hydrophone and listened for pings. deckhands in the rear with a pitchfork. Ostrom says he His floats sauntered extravagantly, first one way, loves this drawing. then another. They spun. They described arcs. They Three days ago, out on the fantail of the Knorr, back meandered. They doubled back. Not one of them in the temperate climate of the Gulf Stream, when sea drifted steadily north, as Swallow had expected. His conditions were, as he put it, “flat-ass calm,” Ostrom floats hadn’t charted rivers in the sea. Instead they had had conducted a crash course in mooring deployment. revealed watery breezes, watery winds, watery storms, Working with a skilled team of specialists, he can and this revelation fundamentally changed the way deploy 10 moorings in a single day, one after another, scientists think of the ocean. even in rough seas. But Bower couldn’t afford to pay There are still oceanographers preoccupied by the the usual team to spend nine days in transit and one ocean’s third dimension, but a growing number— day at work deploying a single mooring. She could perhaps even most—are thinking about its fourth barely afford Ostrom, who was therefore obliged to and darkest dimension: time. Just as geographers press-gang the available able-bodied members of the and cartographers mapped the earth, so the physical unusually small scientific crew. There were only three oceanographers of the 19th century set out to map of us: Kate Fraser, a science teacher from the Perkins the sea—to chart its currents and fathom its depths. School for the Blind, in Watertown, Massachusetts, who As Swallow’s discovery made clear, the geographic was helping Bower develop oceanographic curricula for analogy turned out to be a poor one. What the ocean visually impaired teenagers; Dave Sutherland, a 28-year- resembled most was the skies. Indeed, the “ocean- old doctoral candidate from North Carolina; and me, atmosphere interface” is far more permeable than it a writer who had come along to learn firsthand what looks. The climate of the planet stretches all the way, oceanographic fieldwork was like. oceanographers tell us, from the depths of the Mariana “I’ve been doing this for 34 years,” Ostrom had Trench to the outer edge of the stratosphere. said to us. “When I started, I was 21 years old, 20 years younger than most guys.