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Slippery seas and the motion of the ocean

Ocean River Institute student interns, Dorothy Cooperson Vieweg and Dan Willis talk with Rob about how climate change impacts the ocean. What happens when heat goes into the ocean is easily misunderstood because it is such a foreign place. It is reported that the ocean absorbs 90% of the excess global warming energy. Much of the heat and energy was also taken up by Hurricane Irma bound for the British Virgin Islands, and then, less than two weeks later, Hurricane Maria heading to Puerto Rico. Both underwent very rapid intensification from Category 3 to Category 5 in 24 hours! (Category 5 has four times the energy, destructive power, of Category 4).

In the Gulf of Maine, researchers have been sampling surface water temperatures during summer months. In the summer of 2013, after a decade of taking measurements, a 4-degrees F rise in seawater was found. This indicated that our coastal waters were suffering a more dramatic rise in temperature greater than in 99 percent of the world’s other large bodies of saltwater. It was falsely claimed that Climate Change was having the greatest impact on New England’s ocean waters.

The researchers had mistaken the Gulf of Maine for a slippery sea. To demonstrate what a slippery sea is and how there can be a number of water masses in one water body, Dorothy, Dan, and Rob have taken to Harvard Square’s historic Out of Town News Kiosk with Ocean Science Savvy Wednesdays (2 p.m. to 4 p.m). With water, salt, food coloring, ice and hydrometers made from pencil or clothespin pegs with tacks for ballast, you may check the Plimsoll Lines to see for yourself why the thermohaline circulation with freezing sea ice puts motion into the ocean.

There is some good news with Climate Change for marine life.

The ice cap at the North Pole has gone from covering 2/3 of the Arctic Ocean to covering only 1/3 in the summer, so there is more freezing of seawater come winter. When ice forms, it becomes solid fresh water. The leftover salts are concentrated in the adjacent cold water. This very dense, salty water sinks down into the intermediate water below the surface. As a result of less ice cap, more water exits the Arctic Ocean. The current falls 11,500 feet under the warmer waters of the Atlantic at 175 million cubic feet of water per second in what’s called the Denmark Strait Cataract between Iceland and Greenland. That’s about 2,000 Niagara Falls plunging three times the height of the world’s tallest waterfall, Angel Falls in Venezuela! This intermediate water becomes the nutrient-rich Labrador Current barreling towards the Gulf of Maine. More freezing of seawater at the North Pole becomes more water in the cold Labrador Current that brings more nutrients to support marine life in the Gulf of Maine.