Redfield ratios revisited: Removing the biasing effect of anthropogenic CO2

• Published in: Limnology and Oceanography
• Main Authors: Körtzinger, Arne, Hedges, John I., Quay, Paul D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ASLO (Association for the Sciences of Limnology and Oceanography) 2001
• Subjects: Northeast Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/1542/; https://oceanrep.geomar.de/id/eprint/1542/1/0964.pdf; https://doi.org/10.4319/lo.2001.46.4.0964

Redfield ratios of remineralization are calculated based on chemical data analysis on isopycnal surfaces. The concentrations of dissolved inorganic carbon used in this study were corrected for the anthropogenic CO2 content as estimated with a back-calculation technique. The corrections increased the apparent carbon remineralization by 25-30%, thus proving important for the reliable estimation of Redfield carbon ratios in the presence of anthropogenic CO2. Best estimates from this study largely confirm the more recently published Redfield ratios of remineralization. The following results were obtained for the latitude range 3-41°N along 20-29°W in the Northeast Atlantic Ocean: Corg: P ratio = 123 ± 10; Corg : N ratio = 7.2 ± 0.8; -O2 :Corg ratio = 1.34 ± 0.06; -O2 : P ratio = 165 ± 15; N: P ratio = 17.5 ± 2.0. These ratios are in close agreement with the average composition of phytoplankton and represent respiration of organic matter consisting on average of 52% protein, 36% polysaccharide, and 12% lipid.