An analysis of GOCI measurements for internal waves

Abstract

A two-layer condition occurs Internal Waves in stratified density structure. Physical characteristics of them have been studied around the world with plenty of CTD, Synthetic Aperture Radar and Acoustic Doppler Current Profiler data so far. However, as limitation of discrepancy in field observation, satellite measurements is also widely used to identify them. Propagation and vertical mixing by Internal Waves brings bottom waters up and uplifted nutrient sources which allows optic sensors to define Internal Waves. Optic sensors with a built-in polar-orbit satellite are hard to observe continuous ocean phenomena like a propagation of Internal Waves. Using 1 hourly GOCI measurements, elevations and depressions of Internal Waves can be detected with chlorophyll-a concentration images.Ulleung Basin where Internal Waves frequently occurs is relatively flat bathymetry (-1900m) except abrupt change with Dok island in East/Japan Sea. At least Internal Waves with a scale of ~6km maximum wavelength can appear on 500m spatial resolution GOCI images. In July 2015, 2 packets of Internal Wave are continuously propagated northward across the Dok island during 5 days. To estimate amplitude η of Internal Waves using GOCI images, Hybrid Coordinate Ocean Model and Korteweg-de Vries equation were used for nonlinear coefficient α and linear speed C0. From phase speed C derived from GOCI, amplitudes were extracted by relation with α, However, as limitation of discrepancy in field observation, satellite measurements is also widely used to identify them. Propagation and vertical mixing by Internal Waves brings bottom waters up and uplifted nutrient sources which allows optic sensors to define Internal Waves. Optic sensors with a built-in polar-orbit satellite are hard to observe continuous ocean phenomena like a propagation of Internal Waves. Using 1 hourly GOCI measurements, elevations and depressions of Internal Waves can be detected with chlorophyll-a concentration images.Ulleung Basin where Internal Waves frequently occurs is relatively flat bathymetry (-1900m) except abrupt change with Dok island in East/Japan Sea. At least Internal Waves with a scale of ~6km maximum wavelength can appear on 500m spatial resolution GOCI images. In July 2015, 2 packets of Internal Wave are continuously propagated northward across the Dok island during 5 days. To estimate amplitude η of Internal Waves using GOCI images, Hybrid Coordinate Ocean Model and Korteweg-de Vries equation were used for nonlinear coefficient α and linear speed C0. From phase speed C derived from GOCI, amplitudes were extracted by relation with α,