Judul: Analysis of Upwelling Event in Western Maluku Sea in 2015
Abstrak: Maluku Sea is a secondary entry portal Indonesian Through flow (ITF) with less intensive study. It is connected with Tomini Gulf and Seram-Banda Sea. In the western MS, previous study reported surface features of seasonal upwelling from satellite data. This study aims to further analyze generating force of upwelling and to fully describe oceanic-atmospheric changes before-during-after upwelling event in 2015. The INDESO model output and satellite imagery were used in this study. It is shown that seasonal upwelling in MS is characterized by increased meridional wind stress and northward transport volume, increased sensible heat flux, decreased infrared heat flux, SST cooling, and surface chlorophyll-a blooming. Here, upwelling is generated by southerly monsoon winds, which are fully developed during the Southeast Monsoon period. Since the study area is closed to the equator, the effect of Coriolis may be neglected. In addition, the region between Banggai and Taliabu is relatively opened to Banda Sea. Thus, the strong southerly winds directly drag surface water masses northward and then upwelled colder water occurs in southern region. Upwelling area then evolves towards northeast due to island boundary and is enhanced by recirculation of Maluku ITF. Evolution of mixed layer depth due to upwelling appears in the upper 60 m, which transports water mass northward from June to its peak in September, and decays in October.
Keyword: coastal upwelling, INDESO model output, Indonesian Through Flow, satellite imagery, Maluku Sea

Judul: Stratification of Water Mass and Current  Structure on Lifamatola-Banggai Transect, Maluku Sea
Abstrak: Perairan Selatan Laut Maluku merupakan salah satu jalur masuk Arus Lintas Indonesia (Arlindo) dan merupakan lokasi upwelling musiman yang memberikan produktivitas laut yang tinggi, dan menjadi potensi daerah penangkapan ikan. Penelitian ini bertujuan untuk mendeskripsikan stratifikasi massa air serta struktur arus di bagian selatan Laut Maluku. Hasil dari cruise BUDEE 2022 diperoleh 6 cast data CTD dan 1 Transek SADCP di Selatan Maluku menggunakan Kapal Riset Baruna Jaya VIII. Hasil menunjukan kedalaman lapisan tercampur yang bervariasi antara 43-112 dbar dengan rerata suhu 25,82 (± 0,88) ºC. Ketebalan lapisan termoklin bervariasi antara 97-178 dbar. Sisi barat transek memiliki lapisan termoklin yang lebih dalam dan tebal. Teridentifikasi Massa Air dari NPSW pada lapisan termoklin, NPIW dan SPSLTW di bawah lapisan termoklin. Kecepatan arus meridional di Selat Bote lebih kuat di permukaan dengan kecepatan 0,5 m/s. Sementara itu, wilayah Lifamatola memiliki kecepatan arus zonal yang lebih kuat mengarah ke timur laut. Intrusi dari Selat Bote membawa transpor volume sebesar 0,531 Sv. Upwelling teridentifikasi pada sisi barat transek dicirikan dengan distributi isopiknal, isohalin, dan isotermal yang bergerak naik. Kedalaman klorofil maksimum di sisi barat lebih dangkal pada 24 dbar dan memiliki kadar oksigen terlarut tertinggi di permukaan sebesar 205 μmol/kg memperkuat indikasi fenomena upwelling., The Southern waters of the Maluku Sea are one of the entrances to the Indonesian Throughflow (ITF) and a location for seasonal upwelling, providing high marine productivity and potential fishing grounds. The aim of this study was to describe water mass stratification and current structures in the southern part of the Maluku Sea. Data from 6 CTD casts and 1 SADCP transect were obtained during the BUDEE 2022 cruise in South Maluku using Baruna Jaya VIII Research Vessel. Results showed mixed layer depths ranging from 43-112 dbar with an average temperature of 25.82 (± 0.88) ºC. Thermocline thickness varied between 97-178 dbar. The western transect exhibiting a deeper and thicker thermocline. Water masses including NPSW, NPIW, and SPSLTW were identified in Maluku Sea. Meridional current velocity in Bote Strait was stronger near the surface at 0.5 m/s. Meanwhile, Lifamatola region had stronger zonal currents northeastward. Intrusion from the Bote Strait transported a volume of 0.531 Sv. Upwelling was identified on the western transect characterized by rising isopycnal, isohalin, and isothermal distributions. The maximum chlorophyll depth on the western side was shallower at 24 dbar, with the highest dissolved oxygen concentration at the surface of 205 μmol/kg, reinforcing indications of upwelling.
Keyword: Upwelling, Banggai, Circulation, Stratification, Water mass

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular