NRL field tests ocean glider teams

STENNIS SPACE CENTER, Miss. - Scientists from the U.S. Naval Research Laboratory’s Ocean Sciences Division here in south Mississippi are optimizing the placement of ocean gliders, and the usage of glider data to improve the Navy’s ability to predict ocean conditions. Researchers have frequently used gliders to collect data on ocean conditions. “Predicting the ocean’s interior weather is challenging, yet it has important implications for all those who sail and operate on its waters,” said Dr. Jeffrey Book, an NRL oceanographer. “To help mitigate this problem, the ocean observing community has been developing new techniques for autonomously measuring the ocean’s interior and reporting data back in real time.” Because of the ocean’s vast volume, efficiently placing a small number of gliders to capture observations of a dynamic environment can be tricky. NRL researchers have been looking at ways to optimize glider placement, including using them in teams. Currently, deploying ocean gliders calls for placing them far apart to maximize spatial coverage. But, putting gliders in teams would be adding complexity and change to piloting techniques. Researchers upgraded an existing automated piloting tool for team gliders called Guidance for Heterogeneous Observation Systems (GHOST). It has the ability to optimize single glider use with user-defined and restricted conditions. The researchers spent 18 days off the coast of North Carolina to field test six gliders in the teaming concept. The gliders collected more than 13,000 conductivity, temperature and depth profiles used in two ocean forecast models. “We found that there is little to no benefit in using teams without improving the way you assimilate the data,” said Book. There was some benefit to improving the assimilation method, but the benefit was greatly increased if we used glider teams. The overall improvement Book’s team observed was 9-to-12 percent in improved accuracy of the ocean weather models. (Source: U.S. Naval Research Laboratory 02/18/20) https://www.navy.mil/submit/display.asp?story_id=112114.