Preliminary results of high-frequency autonomous profiler observations for typhoon-ocean interaction study

Abstract

Observations to study the interactions between ocean upper layers and tropical cyclones are very difficult and shipboard measurements are even impossible due to the severe storms and the huge waves. The possible substitutes are unmannedautonomous surface vehicles (ASVs) and/or underwater profilers such as gliders. Another candidate, relatively cheaper than those ASVs or gliders, is an autonomous profiler widely used in Argo program though it cannot be placed properly where it should be. As an instigating experiment, we deployed three autonomous profilers (one in 2017 and two in 2018) in the Northwestern Pacific during the high typhoon season. The 2017 profiler had traditional ARGOS communication unit which the profiling mission cannot be changed after the deployment, while the two 2018 profilers had Iridium unit allowing bidirectional communication to control the profiling mission. The target profiling was upper 500m water column temperature and salinity profiles in every six hour. Though those profilers are not encountered directly the intensive tropical cyclone during the campaigns, several typhoons affect indirectly. Some preliminary results of these observations are discussed with profiling mission controls and plans for further analysis as well as 2019 observation are introduced.