Eddies Affect Subsurface Phytoplankton and Oxygen Distributions in the North Pacific Subtropical Gyre. Issue 15 (3rd August 2020) - Xiu, Peng
Abstract: The North Pacific Subtropical Gyre (NPSG) is an oligotrophic environment where a number of mesoscale eddies occur. With continuous measurements from Biogeochemical‐Argo (BGC‐Argo) floats, we showed that mesoscale eddies can significantly affect the subsurface chlorophyll maximum (SCM) and subsurface biogenic particles. Different responses of the SCM to the cyclonic and anticyclonic eddies and those between the eddy core and edge region were revealed by combining the results from tracked eddies. The variations in the SCM and subsurface particles were further shown to be statistically linked with changes in the dissolved oxygen in the upper oxygen minimum layer. Such an eddy‐induced oxygen change in the central gyre is unresolved in global‐scale coupled models but can contribute to the oxygen variability in oligotrophic environments. Key Points: Physical‐biogeochemical properties of mesoscale eddies were measured by BGC‐Argo floats in the NPSG Mesoscale eddy changes SCM, but its correlation with surface chlorophyll is not significant Changes in SCM lead to variations of the DO concentration in the upper oxygen minimum layer