Construction of a 3D Mooring Array of Temperature Sensors

Abstract

AbstractA small-scale 3D mooring array comprising up to 550 high-resolution temperature sensors was custom designed and constructed. The stand-alone array samples ocean temperature to depths of about 3000 m, limited by the buoyancy elements, at a rate of 1 Hz, with a precision better than 0.5 mK, a noise level better than 0.1 mK, and an endurance of 1 year. Its purpose serves quantitative studies on the development of turbulent mixing by internal wave breaking above deep-ocean topography. The 3D array consists of five parallel cables 105 m long with 3.2 mm inner diameter during the first deployment, now 5.5 mm. The cables are 4 and 5.6 m apart horizontally and are held under tension of 1000 N each using heavy buoyancy elements in a single line above. The entire array is folded into a 6-m high, 3-m-diameter structure above a 750-kg weight. It is deployed in a single overboard operation similar to that of a free-falling mooring. New here is the unfolding of the compacted array when hanging overboard and prior to release into free fall.