Interannual variations of Indonesian Throughflow in its main pathways produced by a data-assimilative ocean model Endro Soeyanto (a*), Yasumasa Miyazawa (b), Bayu Priyono (a)
a) Research Center for Oceanography, National Research and Innovation Agency (BRIN), Kawasan Sains Aprilani Soegiarto, Jl. Pasir Putih 1, Ancol Timur, Jakarta 14430, Indonesia
*endro.soeyanto[at]brin.go.id
b) Application Laboratory, Japan Agency for Marine-Earth Science and Technology 3173-25 Showamachi, Kanazawa-ku, Yokohama City, Kanagawa 236-0001, Japan
Abstract
The interannual variability of sea surface height (SSH) and volume of water masses transport (volume transport) in the primary pathways of Indonesian Throughflow (ITF) and its relationships to the ocean dynamics between the western Pacific Ocean and eastern Indian Ocean associated with the El Nino Southern Oscillation (ENSO) phenomena was examined using the Japan Coastal Ocean Predictability Experiments Forecasting Global Ocean (JCOPE-FGO) reanalysis results from 1993 to 2013. The ENSO condition is represented by the sea surface temperature (SST) anomaly data of the Nino3.4 area (ENSO Index) obtained from NOAA. The variations of calculated interannual SSH and ocean current fields from the reanalysis results indicate their relations to ENSO conditions. The ENSO Index has a negative correlation to the interannual SSH difference between the western Pacific and eastern Indian Oceans. Meanwhile, the result of the correlation calculation of the ENSO Index to the volume transport in the main pathways of ITF shows an immediate (no lag) response at thermocline layers. During the strong ENSO periods, the changes in ocean current structures in the main pathways of ITF.
