Table S1. Estimation of air-sea CO2 fluxes reduction by surfactants in the western Pacific, North Atlantic and Norwegian Fjords. from Global reduction of in situ CO 2 transfer velocity by natural surfactants in the sea-surface microlayer

• Main Authors: Nur Ili Hamizah Mustaffa, Mariana Ribas-Ribas, Hanne M. Banko-Kubis, Oliver Wurl
• Format: Other Non-Article Part of Journal/Newspaper
• Language: unknown
• Published: 2020
• Subjects: Environmental Chemistry; Geochemistry; Oceanography; air–sea gas exchange; surfactant; slick; Western Pacific; Norwegian Fjords; Pacific; North Atlantic
• Online Access: https://doi.org/10.6084/m9.figshare.11733546.v1; https://figshare.com/articles/journal_contribution/Table_S1_Estimation_of_air-sea_CO2_fluxes_reduction_by_surfactants_in_the_western_Pacific_North_Atlantic_and_Norwegian_Fjords_from_Global_reduction_of_i_in_situ_i_CO_sub_2_sub_transfer_velocity_by_natural_surfactants_in_the_sea-surface_micr/11733546

For decades, the effect of surfactants in the sea-surface microlayer (SML) on gas transfer velocity ( k ) has been recognized; however, it has not been quantified under natural conditions due to missing coherent data on in situ k of carbon dioxide (CO 2 ) and characterization of the SML. Moreover, a sea-surface phenomena of wave-damping, known as slicks, has been observed frequently in the ocean and potentially reduces the transfer of climate-relevant gases between the ocean and atmosphere. Therefore, this study aims to quantify the effect of natural surfactant and slicks on the in situ k of CO 2 . A catamaran, sea surface scanner (S 3 ), was deployed to sample the SML and corresponding underlying water, and a drifting buoy with a floating chamber was deployed to measure the in situ k of CO 2. We found a significant 23% reduction of k above surfactant concentrations of 200 µg Teq l –1 , which were common in the SML except for the Western Pacific. We conclude that an error of approximately 20% in CO 2 fluxes for the Western Pacific is induced by applying wind-based parameterization not developed in low surfactant regimes. Furthermore, we observed an additional 62% reduction in natural slicks, reducing global CO 2 fluxes by 19% considering known frequency of slick coverage. From our observation, we identified surfactant concentrations with two different end-members which lead to an error in global CO 2 flux estimation if ignored.