%0 Journal Article
%A Naegler, Tobias
%A Ciais, Philippe
%A Rodgers, Keith
%A Levin, Ingeborg
%D 2006
%F heidok:6713
%J Geophysical Research Letters
%K Gasaustausch , Radiokohlenstoffgas exchange , radiocarbon , carbon cycle
%R 10.11588/heidok.00006713
%T Excess radiocarbon constraints on air-sea gas exchange and the uptake of CO2 by the oceans
%U https://archiv.ub.uni-heidelberg.de/volltextserver/6713/
%V 33
%X We re-assess the constraints that estimates of the global ocean excess radiocarbon inventory place on air-sea gas exchange. We found that the gas exchange scaling parameter aq cannot be constrained by the excess radiocarbon inventory alone. Non-negligible biases in different global wind speed datasets require a careful adaptation of aq to the wind field chosen. Furthermore, aq depends on the spatial and temporal resolution of the wind fields.  We develop a new wind speed- and inventory-normalized gas exchange parameter aqN which takes into account these biases and which is easily adaptable to any new estimate of the ocean excess radiocarbon inventory. Our study yields an average estimate of aq of 0.32+/-0.05 for monthly mean winds, lower than the previous estimate (0.39) from Wwanninkhof (1992). We calculate a global annual average piston velocity for CO2 of (16.7+/-2.9) cm/hr and a gross CO2 flux between atmosphere and ocean of (73+/-10) PgC/yr, significantly lower than results from previous studies.
%Z L11802, doi:1029/2005GL025408