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Stretching for More

WHOI engineers and scientists developed the “Arctic winch” in order to reach up and take critical measurements of surface waters in polar oceans, while minimizing the risk of getting their instruments smashed by ice. To the large top-float of a subsurface mooring, they attached a small buoyant float that carries instruments to measure water temperature, pressure, and salinity. The small float rises on a tether until it detects the ocean surface or the underside of the ice. The float’s pressure sensor detects the rising motion, so if the float bumps against an ice floe, the sensor triggers a winch to reel the small float back out of harm’s way until the next cycle. (Illustration by Jack Cook, Woods Hole Oceanographic Institution)