An autonomous CTD (conductivity-temperature-depth) Argo float was deployed in the deepest Weber Basin of Banda Sea to investigate seasonal changes of the upper-layer seawater properties from the first year of CTD time-series data between August 2017 and July 2018. It is found that the float trajectory formed distinct elliptical-shapes, exhibiting a new picture of deep clockwise circulation of the float parking depth at 1000 m. On seasonal scale, large fluctuation of properties, mixed-layer depth, and thermocline thickness, were associated with seasonal alternating Ekman upwelling and downwelling dynamics. Upwelling “colder” event (July-September) was characterized by outcrops of 27°C isotherm, 34 psu isohaline and 22 kg/m3 isopycnal at sea surface and large lateral variation of salinity in the upper 50 m. In contrast, these properties lines deepen down to about 100 m depth during downwelling “warmer” event (December-February). Amplitude of seasonal temperature change in the upper-layer was about 3°C. The very fresh water episode in the upper-layer was found during the monsoon break in April.

No abstract

No abstract

The Lombok Strait, as one of the outlet straits, is part of the ITF route, which is directly adjacent to the Indian Ocean. There is a sill in the Lombok Strait, which is a place for internal wave generation. Leg-1 data from the Japan Agency for Marine-Earth Science and Technology in collaboration with the Agency for the Assessment and Application of Technology which is part of the Tropical Ocean Climate Study Expedition including CTD Yoyo and ADCP taken using ship vehicles R/V Kaiyo. CTD Snapshot from PUSHIDROSAL using the KRI Spica 934 vehicle part of the Opssurta Baruna Jaya 2 Expedition. Determination of seawater mass stratification with the criteria for the thermocline layer is ≥ 0.05 °C.m-1. Four types of water masses were identified, Java Sea, mixed seawater mass (Java Sea - ITF) which occurred diapycnal mixing, North Pacific Subtropical Water (NPSW) and North Pacific Intermediate Water (NPIW). The seawater mass stratification in the Lombok Strait based on temperature, salinity and density which are seen to follow the internal tidal pattern. The average values for energy dissipation and vertical diffusivity for each layer and replication were 5.73 x 10-7 W.Kg-1 and 3.67 x 10-2 m2.s-1 for CTD Yoyo and 2.25 x 10-6 W.Kg-1 and 7.38 x 10-2 m2.s-1 for CTD Snapshot. The value obtained is greater than the open ocean and straits in other studies. The high shear value confirms this in the thermocline layer. The Richardson gradient value> 0.25 is relatively constant in the thermocline layer.

Penelitian ini bertujuan untuk mengembangkan dan mempermudah pengguna (masyarakat umum) dan TNI AL dalam mengakses serta  menggunakan data Pasut. Kemajuan perkembangan teknologi di bidang digital terutama pemprograman aplikasi berbasis Android saat ini sangat tinggi. Sistem operasi android yang saat ini banyak dipilih oleh masyarakat karena selain murah media komputer tablet dan telephone seluler berbasis android juga sangat mudah dalam pengoperasian aplikasi.  Dibangunnya aplikasi Android informasi pasang surut ini agar memberikan kemudahan dalam mengakses informasi secara cepat dan mudah. Data pasang surut yang akan digunakan adalah dengan pemodelan Tidal Model Driver (TMD) 7.1 dengan validasi data in situ. Dipilih 5 (lima) Pangkalan TNI-AL (Lanal) yang mewakili 4 (empat) tipe pasang surut yang ada di Indonesia Barat, yakni Stasiun Lantamal I Belawan, Lanal Tarempa, Lanal Sibolga, Lanal Ranai (Natuna) dan Lanal Cilacap. Analisis (konstanta) harmonik dilakukan pada penelitian ini, nilai RMSE (35,85 cm - 5,15 cm) serta analisis korelasi Pearson (0.82 – 0,97). Penyusunan basis data dan aplikasi android menggunakan pemprograman berbasiskan Java script.