A model on the carbon cycling in Lake Taihu, China

► A model for carbon cycling in Lake Taihu was developed. ► It was calibrated and validated against the observation of carbon cycling in 2003. ► It can found the carbon dioxide flux on water-air interface and pH in the lake. ► The lake eutrophied water is a sink for the atmospheric carbon dioxide in summer. ► Terrestrial carbon input is the carbon source from the lake to atmosphere.