This ongoing research aims to reconstruct sea surface temperature (SST), Indian monsoon variability, and river discharge dynamics in the Bay of Bengal and South China Sea over the last two millennia using high-resolution coral geochemical proxies. The study utilizes coral skeletal δ¹⁸O, Sr/Ca, B/Ca, and Ba/Ca records preserved within annual growth bands of massive Porites corals to investigate long-term tropical hydroclimate variability. By integrating multiple geochemical tracers, the research seeks to distinguish thermal and hydrological signals associated with monsoon-driven rainfall, freshwater input, salinity variability, and ocean–atmosphere interactions. The study will provide valuable insights into past climate evolution, extreme hydroclimatic events, and regional environmental changes in monsoon-dominated tropical oceans.