A survey of the ¹⁴C content of dissolved inorganic carbon in Chinese Lakes

We present radiocarbon (¹⁴C) measurements of dissolved inorganic carbon (DIC) from surface waters of 11 lakes, widely distributed in China. Surface lake water DIC F¹⁴C values show distinct differences, and we relate these to the physical exchange character (open or closed) of each lake. Open lakes studied here generally have lower DIC F¹⁴C values than closed lakes. We present a simple model of a lake water cycle to calculate an average residence time for each lake. Comparisons between lake DIC F¹⁴C and average residence time shows that the DIC F¹⁴C increases with the average residence time and reflects a steady-state.