[A-OS11] Physical, biogeochemical, and ecological processes and variability in the Indian Ocean

[AOS11-P01] Mean Seasonal Sea Surface Hight Variations within the Makassar Strait

*Kaoru Ichikawa¹ (1.Research Institute for Applied Mechanics, Kyushu University)

Keywords:Makassar Strait, Indonesian Throughflow, Seasonal Sea Surface Height Variations, along-track Jason altimetry data

To study the mean seasonal sea surface height (SSH) variations within the Makassar Strait, we use 19 years of along-track Jason altimetry data processed with the ALES retracker. The seasonal SSH variations are in phase with monsoon seasons over the whole Makassar Strait with increasing amplitudes toward the south, whose results are not affected by interpolation of data outside of the strait. Largest increase is found near the Labani Chanel, where most areas of the strait are shallower than 50 m. The along-strait pressure gradient is found balanced with the bottom friction of the Indonesian Throughflow (ITF) over shallow areas in the strait. Similar significant in-phase SSH variations are found south of Java Island and in the western Pacific Ocean, but nearby SSH variations in the Celebes Sea and the Java Sea show that they are not directly connected to ones in the Makassar Strait. Since all those variations would be induced by monsoon variations, the seasonal SSH variations in the Pacific and Indian Ocean coincidently have the in-phase variations with ones in the Makassar Strait, but they do not dynamically govern the seasonal upper-layer ITF variations in the strait.