An earth science topic Tidal Ellipses Analysis Based on Flow Model Hydrodynamic Data Acquisition in Mandeh Bay, West Sumatera

Abstract

Mandeh Bay is threatened by sedimentation issue caused by the rapid development of marine tourism area which strongly impacts to the environmental degradation. Due to the semi-enclosed area of Mandeh Bay, the tidal current has a significant role in triggering vertical and horizontal transports within the bay. This study aimed to determine the characteristic of tidal current during the southwest monsoon. We developed a hydrodynamic model based on Navier-Stokes equations using a flexible mesh and tidal forecast in which the validation is performed by ADCP data. The simulation results will be used as the basic data to develop a model which depicts the elliptical pattern of tidal current constituents. Offshore rotary tidal currents which are originally semidiurnal reiterate the elliptical pattern every 6 hours and 12 minutes. The strongest semidiurnal current speeds are observed in the bay mouth ranged from 0.1-0.5 m.s-1. The tidal constituent ellipses are oriented more meridionally and in several areas oriented zonally. The current speed of is the highest at all which the speed is averagely one third of magnitude. While, the two main diurnal tidal constituents ( and ) have the maximum speeds approximately one fifth of magnitude. Thus, the domination of semidiurnal constituents may trigger sediment distribution and accumulation within the bay because of its twice tidal oscillations entering the bay.

Velocity Components of Currents and Transport Mechanism in the Ie Meulee Waters, Weh Island, Indonesia

“…The semi minor axes of ellipses formed are primarily positive which rotate clockwise. This pattern was induced by the local topographical conditions, Coriolis force, Ekman current and wind pressure differential (Wisha et al, 2019).…”

“…Gemilang and Wisha (2018) defined the current-distributed surface temperature within Sabang Bay. While Wisha et al (2019) studied the influence of oceanography features on controlling aquaculture wastes within Sabang Bay. Edyanto (2008) focused on the physical characteristics of environment in Sabang Port.…”

Identifikasi Arus Pasang Surut di Perairan Kemujan, Karimunjawa Berdasarkan Data Pengukuran Acoustic Doppler Current Profiler

“…Secara umum berdasarkan hasil pada tabel 1, kecepatan arus berkurang seiring dengan bertambahnya kedalaman, terlihat bahwa kecepatan arus maksimal berada pada kolom perairan yang paling dekat dengan permukaan. Pola profil kecepatan yang sama juga terjadi pada penelitian di Mandeh Bay, Sumatera Barat oleh Wisha et al (2019), kecepatan arus di lapisan permukaan adalah yang terkuat dan secara bertahap menjadi lebih lemah dengan bertambahnya kedalaman. Hal ini diduga karena adanya pengaruh gaya coriolis dan efek gesekan dasar.…”

“…Identifikasi dilakukan dengan memisahkan arus total menjadi arus pasang surut dan arus non-pasang surut/residu (Beliyana et al, 2020). Penggunaan data ADCP untuk analisa arus pasang surut sudah dilakukan pada penelitian-penelitian sebelumnya (Wang et al, 2004;Vindenes et al, 2018;Wisha et al, 2019;Siagian et al, 2021).…”

Internal solitary waves in the Northwest Sumatra Sea-Indonesia: from observation and modeling

“…Tidal currents are generated from 10 tidal components extracted from TPXO7 data, including principal lunar (M2), principal solar (S2), larger lunar elliptic (K2), luni solar (N2), luni solar (K1), principal lunar (O1), principal solar (P1), lunar fortnightly (Mf), lunar monthly (Mm), and solar semiannual (Ssa). The results of tidal current extraction are described in the form of a tidal ellipse parameter consisting of a semi-major and semi-minor axis representing the maximum and minimum current velocity, the inclination is the anticlockwise angle between the east and the semi-major axis [19].…”