The influence of transformed Reynolds number limitation on gas transfer parameterizations and global DMS and CO<sub>2</sub> fluxes

Abstract

Abstract. Eddy covariance measurements show gas transfer velocity limitation at medium to high wind speed. A wind-wave interaction described by the transformed Reynolds number is used to characterize environmental conditions favoring this limitation. We take the transformed Reynolds number parameterization to review the two most cited wind speed gas transfer velocity parameterizations, Nightingale 2000 and Wanninkhof 1992/2014. We propose an algorithm to correct for the effect of gas transfer limitation and validate it with two gas transfer limited directly measured DMS gas transfer velocity data sets. A 5 correction of the Nightingale 2000 parameterization leads to an average increase of 22 % of its predicted gas transfer velocity.The increase for Wanninkhof 2014 is 9.85 %. Additionally, the correction is applied to global air-sea flux climatologies of CO 2 and DMS. The global application of gas transfer limitation leads to a decrease of 6-7 % for the uptake CO 2 by the oceans and to decrease of 11 % of oceanic outgassing of DMS. We expect the magnitude of Reynolds limitation on any global air-sea gas exchange to be about 10 %.