The Makassar Strait throughflow and its jet

Abstract

[1] A nested numerical model system has been set up to realistically simulate almost 40 years of the Indonesian throughflow (ITF). A global circulation model delivered the boundary values for sea surface height, temperature and salinity distribution to a fine resolution regional model of the ITF. The results of the regional model are in good agreement with measured data regarding velocity distribution, stratification as well as transported water masses, even though the division of the ITF volume transport into its western and eastern branches differs slightly from estimates from other model results or measurements. The results show a current system highly variable in space and time. Here, the analysis of model results focuses on the western branch of the ITF, the Makassar Strait throughflow, which is estimated to account for up to 50 to 80% of the entire ITF. The climatology and the mean vertical structure are presented. The model results show that the Makassar Strait throughflow occurs as a distinct current, which we termed Makassar Current. It is regionally developed as a subsurface jet, and it behaves like a western boundary current as it is attached to the western boundary (Sunda Shelf edge) along its entire path from the Sulawesi Sea through the Makassar Strait to its direct exit through the Lombok Strait. It appears from model experiments that the local wind stress counteracts the Makassar Strait throughflow.

Sediment Composition and Facies of Coral Reef Islands in the Spermonde Archipelago, Indonesia

“…In contrast, P. Panambungan shows a mean D90 value of 434 µm. These differences in mean grain size of surface sediments may be explained by a higher wave energy during the NW monsoon period from December to January (Mayer and Damm, 2012), and a stronger hydrodynamic setting influenced by the Indonesian Through-Flow at the Spermonde shelf rim (Renema and Troelstra, 2001). …”

“…This current shows a high temporal variability, due to the monsoonal changes in mean wind directions (Figure 2, Mayer and Damm, 2012). The NW monsoon during boreal winter, especially in December and January, accelerates the surface flow to the south.…”

The Spatial and Temporal Variability of Air-Sea CO2 Fluxes and the Effect of Net Coral Reef Calcification in the Indonesian Seas: A Numerical Sensitivity Study

“…It is impressive to see the seasonal variation at location 7, eastern Java Sea: During the first and last quarters of a year, the location is effected by relatively fresher water masses coming from the South China Sea, whereas during boreal summer season, this region is effected by the saltier Makassar Current coming from the North Pacific Ocean (Mayer and Damm, 2012).…”

Spatial and Temporal Variation of Indonesian Throughflow in the Makassar Strait

“…Besarnya transport Arlindo Makassar selama periode Musim Timur (Juli -September) lebih kuat dibandingkan dalam periode Musim Barat (Desember -Februari) (Gordon et al, 2010;Susanto et al, 2012). Model sirkulasi menunjukkan terjadi intensifikasi tepi barat dari Jet Arlindo Makassar di sepanjang lintasan selat ini (Mayer and Damm, 2012). Hasil pengukuran langsung dalam program EWIN-2013 menunjukkan bahwa massa air Arlindo Makassar (NPSW dan NPIW) bervariasi secara spasial dimana stratifikasi massa air itu lebih tegas karakternya di tepi barat dibanding dengan tepi timur selat, yang berasosiasi dengan penguatan Arlindonya (Horhoruw et al, 2015).…”