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Why the Gulf Stream is flowing stronger and the Gulf of Maine is not warming faster
An ice cube in a pint glass demonstrates how the shrinking polar ice cap gives more flow to a stronger Gulf Stream, while an ice cube in the adjacent pint glass demonstrates why Gulf of Maine seawater is not warming faster than any other water body.
August 2018, on the hot bricks of Boston’s City Plaza at the 11th Annual Boston Greenfest where air temperatures climbed into the nineties, the intent was to demonstrate how ocean currents circulate around the Atlantic Ocean with a pint glass, water, salt, a single ice cube to play the part of an iceberg, and a splash of blue food coloring. Beneath the Ocean River Institute banner, two pint glasses of fresh water were set out on a green plastic table cloth. Salt was poured into one glass and stirred. A single ice cube went into each glass. One drop of blue food coloring was placed on top of each ice cube. Festival goers leaned forward or squatted a bit to see horizontally into the two glasses.
Blue dye in the glass of salt water puddled around the ice cube on the surface. The glass of fresh water drew everyone’s attention as feathery streams of dark blue dye cascaded off the ice cube down to the bottom of the glass. If this is all fresh water why is the blue water sinking so fast, I asked. The answer was that melt water off the ice…
