2023/07/01 by Hugo Bellenger, Laurent Bopp, Christian Éthé +8 · 1 voice · 2 citations
Earth and Planetary Sciences · Environmental Science · #Atmospheric and Environmental Gas Dynamics #Climate variability and models #Marine and coastal ecosystems
paper · pdf · doi:10.1029/2022jc019479
openalex publication_date 2023/07/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
Abstract The ocean skin is composed of thin interfacial microlayers of temperature and mass of less than 1 mm where heat and chemical exchanges are controlled by molecular diffusion. It is characterized by a cooling of ∼−0.2 K and an increase in salinity of ∼0.1 g/kg (absolute salinity) relative to the water below. A surface observation‐based air‐sea CO 2 flux estimate considering the variation of the CO 2 concentration in these microlayers has been shown to lead to an increase in the global ocean sink of the anthropogenic CO 2 by +0.4 PgC yr −1 (15% of the global sink). This study analyzes this effect in more details using a 15‐year (2000–2014) simulation from an Earth System Model (ESM) that incorporates a physical representation of the ocean surface layers (diurnal warm layer and rain lenses) and microlayers. Results show that considering the microlayers increases the simulated global ocean carbon sink by +0.26 to +0.37 PgC yr −1 depending on assumptions on the chemical equilibrium. This is indeed about 15% of the global sink (2.04 PgC yr −1 ) simulated by the ESM. However, enabling the ocean skin adjustment to feedback on ocean carbon concentrations reduces this increase to only +0.13 (±0.09) PgC y −1 . Coupled models underestimate the ocean carbon sink by ∼5% if the ocean skin effect is not included.