Analysis for effects of monsoon activities on oxygen and hydrogen isotopes variation based on Hong Kong GNIP long-term data

Through 58-yr isotopic data (3H, 18O, and 2H) in monthly precipitation for Hong Kong, we discuss how main controls, especially monsoon activities, effect temporal variation of isotopes in precipitation. By comparing the local meteoric water lines, we find that the recycled water vapor and sub-evaporation cause the slope of LMWL lower whereas the recycled water vapor supersaturated non-equilibrium condensation makes it higher. Given the “reverse temperature effect” in Hong Kong, we caution the use of temperature effect for paleoclimate reconstruction in humid and monsoonal locations. Our findings provide evidences on how environmental and anthropogenic factors affect precipitation isotopes in monsoonal areas.