Struktur vertikal upwelling – downwelling di Samudera Hindia Selatan Jawa hingga Selatan Bali berdasarkan salinitas musiman periode 2004 – 2010

Abstract

Abstract. Salinity plays an important role for phenomenon identification of upwelling and downwelling. Upwelling that occurs in the Indian Ocean south of Java to South of Bali is influenced by monsoons, ENSO (El Nino Southern Oscillation) and IOD (Indian Dipole Oscillation Mode). Upwelling and downwelling patterns based on vertical structure of salinity and its seasonal variability within seven years (2004 to 2010) is studied here. Argo Float dataset is used in this study, processed by Ferret software for a vertical schematic model, and Pearson correlated with IOD and SOI indexes. The aim of this study is to  obtain the pattern of upwelling and downwelling based on profile of seasonal salinity during the period 2004-2010 in Indian Ocean south of Java – Bali and correlated with ENSO and IOD.  Further discussion on upwellling is provided since it is more important to the fisheries activity. Result shows an intensive upwelling phenomenon occurs at 110°E correlated with fishing ground area. ENSO and IOD phenomena has been founded also affect upwelling. Upwelling increasing in intensity during the La Nina - IOD (+). The upwelling is negative linear correlated with SOI(-0,89643), but its positive linear correlated with IOD (+0,798168).

Keywords : vVrtical structure salinity; Seasonal upwelling; Indian Ocean; South Java-Bali Seas.

Abstrak. Salinitas berperan penting untuk mengidentifikasi fenomena upwelling dan downwelling. Upwelling yang terjadi di samudera Hindia Selatan Jawa hingga Selatan Bali dipengaruhi oleh angin musim, ENSO (El Nino Southern Oscillation) dan IOD (Indian Oscillation Dipole Mode). Dalam peneletian ini dikaji pola upwelling dan downwelling berdasarkan distribusi salinitas secara vertikal dan vaeriabilitas musiman dikaji dalam waktu tujuh tahun (2004 – 2010). Data hasil akuisisi argo float digunakan dalam penelitian ini, diolah menggunakan software Ferret selanjutnya dilakukan  pembuatan model skematik  dan analisa korelasi pearson terhadap Indeks IOD dan SOI. Tujuan dari penelitian ini untuk memperoleh pola upwelling dan downwelling terhadap musim berdasarkan profil salinitas selama periode 2004 – 2010 di Samudera Hindia Selatan Jawa hingga Bali dan hubungannya dengan fenomena ENSO dan IOD.Penelitian lebih lanjut tentang upwelling penting untuk industri perikanan. Hasil penelitian menunjukkan Fenomena upwelling secara intensif terjadi pada koordinat bujur 110°BT, menunujukkan adanya kesesuaian dengan lokasi daerah penangkapan ikan. Fenomena ENSO dan IOD juga mempengaruhi upwelling, intensitasnya meningkat saat periode La Nina-IOD (+). Upwelling berkorelasi negatif terhadap SOI (-0,89643), sedangkan  upwelling berkorelasi posetif dengan IOD (+0,798168).

Kata Kunci: Struktur vertikal salinitas; Upwelling musiman; Samudera Hindia; Laut Selatan Jawa-Bali