Constructing the three-dimensional structure of an anticyclonic eddy with the optimal configuration of an underwater glider network

Abstract

Mesoscale eddies, as a considerable transporter of ocean heat, dissolved oxygen and other biochemical tracers, have an important influence on the distribution of marine resources and global climate change. The observation of their three-dimensional (3D) structure will facilitate the understanding of eddy dynamics. Underwater gliders have been applied in observing the mesoscale eddies in recent years. The main objective of this paper is to determine the optimal configuration of an underwater glider network for reconstructing the 3D structure of an anticyclonic eddy in the northern South China Sea. Based on a simple parameterized model for the temperature anomaly field of the eddy, a numerical experiment was performed to test three glider network topologies (two perpendicular parallel patterns and one crossing pattern). A comprehensive metric combining three metrics was proposed to evaluate the reconstruction performance. The relationship between the metric and configuration of the glider network including the number and allocation was revealed. Comparing the reconstruction performance of different configurations, the optimal number and topology of gliders in the network were determined. The numerical results demonstrate the efficiency of the glider network with an appropriate configuration in observing the 3D structure of a mesoscale eddy. From August 4 to 29, 2017, a field experiment was conducted by Tianjin University in northern South China Sea to verify the simulation results. The results of this research can be applied to the design of glider networks for observing the mesoscale eddies’ 3D structure in situ.