Evidence of O-2 consumption in underway seawater lines: Implications for air-sea O-2 and CO2 fluxes

作者：Juranek Lauren W^*; Hamme Roberta C; Kaiser Jan; Wanninkhof Rik; Quay Paul D

来源：Geophysical Research Letters, 2010, 37: L01601.

DOI：10.1029/2009GL040423

We observed O-2 deficits of 0.5 to 2.0% (1 to 4 mu mol/kg) in the underway seawater lines of three different ships. Deficits in O-2/Ar and isotopic enrichments in dissolved O2 observed in underway seawater lines indicate a respiratory removal process. A 1% respiratory bias in underway lines would lead to a 2.5-5 mu atm (2.5-5 mu bar) enhancement in surface water pCO(2). If an underway pCO(2) bias of this magnitude affected all measurements, the global oceanic carbon uptake based on pCO(2) climatologies would be 0.5-0.8 Pg/yr higher than the present estimate of 1.6 Pg/yr. Treatment of underway lines with bleach for several hours and thorough flushing appeared to minimize O-2 loss. Given the increasing interest in underway seawater measurements for the determination of surface CO2 and O-2 fluxes, respiration in underway seawater lines must be identified and eliminated on all observing ships to ensure unbiased data. Citation: Juranek, L. W., R. C. Hamme, J. Kaiser, R. Wanninkhof, and P. D. Quay (2010), Evidence of O-2 consumption in underway seawater lines: Implications for air-sea O-2 and CO2 fluxes, Geophys. Res. Lett., 37, L01601, doi: 10.1029/2009GL040423.