General data about 22 Chinese lakes.xlsx

In this study, we analyzed the contents and isotopic compositions of BC in surface sediments from 22 lakes across China. The BC contents ranged from 0.02 to 0.70% and the BC/TOC ratio ranged from 3.1% to 24.6%. Our findings based on δ13C and Δ14C data indicate that fossil fuel combustion is the primary source of sediment BC, contributing 28% to 91% (average 73%), with the highest in in the most developed eastern China and the lowest in the less developed southwestern and northwestern China (QTP and IMXP). The highest BC burial rates were observed in the NEP and YGP, followed by the EP and QTP, with the IMXP exhibiting the lowest rates. As of 2014, the total BC burial flux in Chinese lakes was estimated to be 122.2 Gg yr-1, which is comparable to the BC burial fluxes in China's offshore regions. However, due to the smaller lake area, Chinese lakes exhibit substantially higher BC burial rates per unit area than marginal seas and deep oceans, making them an important sink for BC.