PhD Oral Defense of Riovie Ramos: Coral records of the Kuroshio Intrusion across the Luzon Strait: variability and controlling factors
- Oral Defense
About the Event:
The Kuroshio-dominated water exchange across the Luzon Strait transports heat, salt and nutrients from the Pacific across the strait and into the South China Sea (SCS), significantly impacting the climate, circulation and marine ecology in the region. Records of key climatic influences on surface water variability across the Luzon Strait are therefore critical to better understand its variability, drivers and interaction with the Indo-Pacific climate. I present coral-derived records of sea surface temperature (SST), sea surface salinity (SSS) and water circulation from two sites across the Luzon Strait—Palaui, northeastern Philippines and Houbihu, southern Taiwan—to investigate the role of climate in the Kuroshio intruding process. The reconstructed SST and salinity records in Palaui indicate the dominant influence of Pacific-centric climatic oscillations, such as the Pacific Decadal Oscillation (PDO) and the El Niño-Southern Oscillation (ENSO). In contrast, the reconstructed SST in Houbihu exhibit hemispheric scale SST patterns driven by global forcing factors. Compared with the reconstructed salinity record in Palaui, the Houbihu salinity record provides evidence of the role of the PDO in the advection of Pacific waters into the Luzon Strait at decadal timescales. A more conservative recorder of water circulation, records of radiocarbon in the region including two new records from our sites, reveal the dominant influence of ENSO in driving the Kuroshio Intrusion into the SCS at interannual timescales. These findings help to improve our understanding of the complex interactions between different climate systems and the Kuroshio Intrusion into the SCS, likely influencing regional and global oceanographic variability.
Members of the Examination Committee:
- Assistant Professor Patrick Martin (Internal Examiner), Nanyang Technological University, Singapore
- Associate Professor Kristine DeLong, (External Examiner) Louisiana State University, USA
- Distinguished Professor Chuan-Chou (River) Shen (External Examiner), National Taiwan University, Taiwan R.O.C
Oral Examination Committee:
- Associate Professor Fidel Costa (Chairman), Nanyang Technological University, Singapore
- Professor Edgardo Manuel Latrubesse (Oral Examiner), Nanyang Technological University, Singapore
- Assistant Professor Patrick Martin (Oral Examiner), Nanyang Technological University, Singapore
About the Speaker:
Riovie Ramos received her BSc in Geology and MSc in Marine Science from the University of the Philippines (UP), Diliman. Her MSc thesis focused on reconstructing coral reef response to sea level and temperature changes based on two mid-Holocene uplifted reef sequences in the Philippines. While pursuing her MSc degree, Riovie served as a Research Assistant at the Marine Science Institute, UP Diliman. In 2013, she worked as a Research Associate at the Marine Geochemistry Lab, Earth Observatory of Singapore before joining as a Ph.D. student at the Asian School of the Environment, Nanyang Technological University under the supervision of Dr. Nathalie Goodkin. In her Ph.D. work, she used corals to reconstruct past changes in sea surface temperature, salinity and surface ocean circulation to investigate drivers of climatic and oceanographic variability in the Southeast Asian marginal seas.