Large CO2 disequilibria in tropical lakes
نویسندگان
چکیده
[1] On the basis of a broad compilation of data on pCO2 in surface waters, we show tropical lakes to be, on average, far more supersaturated and variable in CO2 (geometric mean ± SE pCO2 = 1804 ± 35 matm) than temperate lakes (1070 ± 6 matm). There was a significant negative relationship between pCO2 and latitude, resulting in an average decrease of pCO2 by 2.8 ± 0.5% per degree latitude. In addition, we found a general positive relationship between pCO2 and water temperature across lakes involving an average increase (±SE) in 6.7 ± 0.8% per C. A conservative annual efflux from global lakes to the atmosphere was reestimated to 0.44 Gt C. Our results show tropical lakes maintain large CO2 disequilibria with the atmosphere, playing a disproportionate and variable role in the flux of CO2 between lakes and the atmosphere, thereby being a significant component of the global C cycle.
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