Characteristics of Internal Waves in the Bali Sea from Sentinel-1A Data and Ocean Modeling
Anszel Lukman (a), Agus Saleh Atmadipoera (a*), Dwiyoga Nugroho (b), Gentio Harsono (c)

a) Marine Science and Technology Department, IPB University, Bogor Regency 16680, West Java, Indonesia
*atmadipoera_itk[at]apps.ipb.ac.id
b) National Research and Innovation Agency, Central Jakarta 10340, DKI Jakarta, Indonesia
c) Hydrography and Oceanography Centre of Indonesian Navy, North Jakarta 14430, DKI Jakarta, Indonesia

Abstract

Internal waves (IWs) that propagate into the Bali Sea are supposed to originate from the sill area in the southern part of the Lombok Strait. This study aims to investigate surface features and mechanism of IWs formation and propagation into the Bali Sea. The datasets are acquired from the Sentinel-1A imageries and CROCO simulation. The results showed that solitary wave packets are spread over two areas: near Lombok Strait as generating area, and in the western and northern parts of the Bali Sea as propagating area. The length of IWs crests increased as they moved into the propagation area. The model showed that mixed semidiurnal tidal currents near the sill flow northward (southward) alternately during the flood (ebb) tidal period, resulting in the pycnocline deepening down to ~400 m near the northern sill area during the flood tide. Furthermore, the model demonstrated an alternating upward and downward movement of vertical currents components, associated with propagation of IWs^ crests and troughs along IWs pathway.

Keywords: Bali Sea- Lombok Strait- internal waves- sill- Sentinel-1A imagery- CROCO model- tidal current

Topic: Operational Oceanography