The UIS ocean unit (CT package) consisted of five conductivity & temperature sensors (RBR duo CT), one conductivity, and temperature & depth (pressure) sensor (RBR concerto CTD). The ocean unit were used to measure upper ocean at the depths of about 5-40 m, with the initial depths of 5.4, 10.4, 15.4, 20.4, 25.4, and 40.4 m. The ice and ocean units of UIS were deployed 10 m apart. The changes in the depths of CT sensors were estimated based on their initial depths and the depth measured by the CTD at the bottom of CT package.