Distribution and characteristics of internal waves observed during The Expedition of Jalacitra 3-2023 “FLORES”

¹ Department of Marine Science, Post-Graduate School, Faculty of Fisheries and Marine Science, IPB University, 16680, Bogor, Indonesia
² Marine Science and Technology Department, Faculty of Fisheries and Marine Sciences, IPB University, 16680, Bogor, Indonesia
³ Faculty of Defence Technology, Republic Indonesia Defence University, Bogor, 16810. Indonesia
⁴ Research Center for Oceanography, National Research and Innovation Agency, 10340, Central Jakarta, DKI Jakarta, Indonesia
⁵ Department of Hydro-Oceanography, Indonesian Naval Technology College (STTAL), Indonesian Navy, 14240, Jakarta, Indonesia
⁶ Naval Hydro-Oceanography Center (PUSHIDROSAL), Indonesian Navy, 14430, Jakarta, Indonesia

^* Corresponding authors: sumardanai@apps.ipb.ac.id

Abstract

Navigation safety and the advent of Internal Solitary Waves (ISWs) are inextricably linked. In the Flores Sea, the processes of generation, propagation, and shoaling of ISWs have both positive and negative effects. The objective of the Expedition Jala Citra (EJC) 3-2023 “Flores” is to identify the ISWs through hydro-oceanography survey acoustic apparatus on the Navy Ship, KRI Spica 934. The objective of this study was to qualitatively map the distribution and characteristics of ISWs around the Flores Sea, the Alor Strait, the Ombai Strait, and the Leti Strait. The results of the observation data processing indicate that solitary waves dominate internal waves, with amplitudes ranging from 20 m to 100 m. The distribution pattern in the study area was consistent with the appearance obtained from the satellite image recording. The results of the processing of the water column data on this expedition demonstrated the role of the background current in altering the high (low) amplitude of the ISWs. The occurrence of ISWs in the Leti Strait and the southward propagation of ISWs during the neap tide in the Ombai Strait provide new information for future ISW research. It is anticipated that this information will be used to update nautical chart information, thereby supporting underwater navigation safety.