Introduction to the Lecture

The Indonesian seas feature a wide spectrum of variations in hydrography and circulation. This study applies a simple frequency-based time series decomposition method to the 20-year (2000-2019)model simulation, revealing the spatial distributions of intra-seasonal, semi-annual, annual, and inter-annual variation, respectively. K-means clustering based on the decomposed variability is used to explore dynamical similarities and differences among different basins of the Indonesian seas, highlighting the competing impacts of annual and inter-annual variations. The Indonesian seas lie at a "crossroad where the inter-annual variation dominates in a NE-SW oriented deep-ocean regime, while the annual variation prevails in a NW-SE oriented marginal sea regime. The former is primarily associated with the ENSO induced Rossby waves from the equatorial Pacific Ocean, whereas the latter is driven by the local monsoonal winds. Moreover, the current profiles reveal significant differences between the main and east branches of the Indonesian Throughflow such that the interannual anomalies occur in opposite directions and that the annual variations are more prominent above(below)the thermocline in the main (east) branch.

Profile of the Speaker

Xue Huijie, a Ph.D. graduate from Princeton University, is currently a distinguished professor at Xiamen University. She has successively served as a postdoctoral researcher and research assistant professor at the Department of Marine Science at the University of North Carolina, and as an assistant professor, associate professor, and professor at the University of Maine. From 2013 to 2020, she was selected as a national distinguished expert (Overseas High-level Talent Introduction Program) and a part-time researcher at the State Key Laboratory of Tropical Oceanography and Environment, South China Sea Institute of Oceanology, Chinese Academy of Sciences. She has served as the chairperson of the International Steering Committee of IWMO, and is currently the deputy editor-in-chief of Progress in Oceanography and an editorial board member of Ocean-Land-Atmosphere Research. Her main research interests are marine dynamic processes and numerical simulation, marginal sea dynamics, western boundary currents, fronts and eddies in the ocean, offshore prediction and application, physical-biological coupled models, and regional air-sea interactions.