Deciphering the Solutes Production and Transport Processes in Asian Monsoonal Rivers from Concentration-Discharge Relationships

The negative feedback between chemical weathering and climate variability is hypothesized to play an important control on modulating atmospheric CO₂ over long and short timescales, affecting the evolution of Earth's temperature and climate. The role of both hydrology, to overcome transport limitation, and weatherability, controlling weathering reaction limitations, are two important factors that influence the weathering fluxes from catchments.The concentration-runoff relationships is controlled by ion sources, behaviors and the lithology (i.e., reactivity) of catchments. The among-catchment behavior of dissolved solutes responding to changing runoff is correlated to the average Damköhler number (Da) of each catchment. Rivers with high average Da induce high maximum weathering fluxes, while the maximum weathering potential is primarily controlled by the Damköhler coefficient among the catchments in our study. Asian monsoonal rivers have higher weathering fluxes and weathering potential than most global rivers. Globally, HCO₃^- behaviors and weathering characteristics are highly influenced by spatial carbonate distribution. Our work deciphers the mechanisms that link runoff, fluid transit time and weathering fluxes in Asian monsoonal rivers and analyzed the controlling factors on solutes dynamics on global scale.