%0 Generic
%A Muhammad , Dicky Darmawan	
%C UNIVERSITAS LAMPUNG
%D 2024
%F eprints:82820
%I FAKULTAS PERTANIAN
%T ANALISIS ARUS GEOSTROPIK BERDASARKAN KETINGGIAN  MUKA LAUT DAN KAITANNYA DENGAN KEJADIAN UPWELLING  DI PERAIRAN SAMUDRA HINDIA BAGIAN TIMUR
%U http://digilib.unila.ac.id/82820/
%X Fenomena oseanografi di Samudra Hindia terjadi akibat interaksi antara atmosfer    dan laut. Interaksi ini menyebabkan perubahan kondisi laut, salah satunya perbe-  daan tinggi muka laut. Perbedaan tinggi muka laut pada dua lokasi di lautan akan    menghasilkan gradien tekanan. Arus laut akan bergerak dari tekanan tinggi ke te-  kanan rendah. Namun, karena pengaruh gaya coriolis, arah arus akan dibelokkan.    Arus yang dihasilkan dari keseimbangan antara gradien tekanan dan gaya Coriolis  disebut arus geostropik. Tujuan penelitian ini adalah untuk menganalisis arus    geostropik yang dihasilkan dari perbedaan tinggi muka laut, menganalisis ang-  kutan Ekman, dan mengidentifikasi hubungannya dengan fenomena upwelling,    yang diverifikasi menggunakan distribusi suhu permukaan laut dan klorofil-a.    Metode penelitian ini menggunakan perhitungan arah dan besarnya arus geostro-  pik berdasarkan perbedaan tinggi muka laut. Arah dan besarnya arus geostropik    kemudian dipakai untuk menghitung angkutan Ekman dan mengidentifikasi ke-  jadian upwelling. Kejadian upwelling diverifikasi menggunakan distribusi suhu    permukaan laut dan klorofil-a. Data yang digunakan dalam metodologi penelitian  meliputi tinggi muka laut, suhu permukaan laut, dan klorofil-a antara periode    2016-2020. Hasil penelitian menunjukkan bahwa pola arus geostropik tidak ber-  beda secara signifikan antar tahun. Variabilitas terjadi pada besarnya dan inten-  sitas eddies secara musiman. Secara umum, di laut lepas, arus geostropik mem-  bentuk pola lingkaran yang disebut eddies. Pola arus pada eddies bergerak searah    jarum jam (siklonik) di zona konvergen dan bergerak berlawanan jarum jam (anti-  siklonik) di zona divergen. Di daerah pantai, arus geostropik cenderung bergerak    ke arah barat di barat Sumatra dan timur di selatan Jawa. Angkutan Ekman cen-  derung bergerak 90° ke kanan arus geostropik. Oleh karena itu, angkutan Ekman    bergerak menuju pantai di barat Sumatra dan menjauhi pantai di selatan Jawa.  Kondisi ini menyebabkan upwelling hanya terjadi di selatan Jawa dan puncaknya  pada musim timur, sehingga disebut upwelling musiman. Kejadian upwelling di  laut lepas jarang terjadi karena angkutan Ekman di zona divergen tidak dapat  membawa massa air akibat stratifikasi termoklin yang lebih dalam.  Kata kunci: Arus geostropik, angkutan Ekman, upwelling, Samudra Hindia    The phenomena oceanography of the Indian Ocean is affected by the interaction  between the atmosphere and the ocean. This interaction causes changes in ocean  conditions, one of which results in differences in sea level high. The different sea  level high between two places in the ocean will cause a pressure gradient. The  ocean current will move forward from high pressure to low pressure. Due to the  influence of the coriolis force, the direction of the current will be deflected. The  current resulting from the balance between the pressure gradient and coriolis force  is called the geostrophic current. The aims of this research ware to analyze the  geostrophic current resulting from the different of sea level height, analyze the    Ekman transport, and identify its relation to upwelling phenomena, which are ve-  rified using sea surface temperature and chlorophyll-a distribution. The quantita-  tive method used in this research, by calculating the direction and magnitude of    the geostrophic current based on differences in sea level high. The direction and  magnitude of the geostrophic current the used to calculate the Ekman's transport  and identify upwelling events. The upwelling events verified by the distribution of    sea surface temperature and chlorophyll-a. The data used in the research methodo-  logy include sea level high, sea surface temperature (SST), and chlorophyll-a bet-  ween the period of 2016-2020. The results of this research showed that the pattern    of the geostrophic current did not differ significantly between years. The variabili-  ties occured in the magnitude and intensity of eddies. These variabilities occured    seasonally. In general, at the open ocean, the geostrophic current formed a circular  pattern called eddies. These circular patterns moved clockwise (cyclonic) in the  convergence zone and moved anticlockwise (anticyclonic) in the divergence zone.  In the coastal area, the geostrophic current tend to moved towards to the west in  western Sumatra and east in southern Java. The Ekman transport tend to move 90o  to the right of the geostrophic current. Therefore, it will move towards the coast in  western Sumatra and away from the coast in southern Java. This condition caused  upwelling to only occured in southern Java and its peak only occured in the east  monsoon, so it was called seasonal upwelling. The upwelling event in the open  ocean rarely occured because the Ekman transport in the divergence zone was  unable to receiver water mass due to the deeper thermocline stratification.  Key words: Geostrophic current, transport Ekman, upwelling, Indian Ocean