Initial set of oceanographic data from Bay of Bengal using an underwater glider as mobile sensor node

Abstract

Underwater gliders measure high-resolution spatiotemporal oceanographic data. However, glider operations have not been carried out in the Indian Ocean region so far. In September 2013, the National Institute of Ocean Technology, Chennai introduced a mobile sensor node, the underwater glider ‘Barathi’, for observation in the Bay of Bengal (BoB). Herein we address ballasting procedure of the glider operated in highly variable density waters of the BoB. The temperature and conductivity data collected by us are strongly correlated with commercially available instrument with coefficient of determination R2 > 0.97. This article reports results from a long-duration (127 days) mission in 2014. The variation of temperature, salinity, density, sound velocity, mixed layer depth, sonic layer depth and lower cutoff frequency of surface duct along 13°N lat. and between 80.76°E and 86.28°E long. are also presented. The results show a trace of the East Indian Coastal Current. The glider operations demonstrate a novel in situ observation platform in the BoB.