Annual Carbon Export at the North Pacific Axial Seamount

Abstract

As anthropogenic CO2 levels rise, it becomes increasingly important to quantify the flux from the surface ocean down into the deep, where it may be sequestered for thousands of years. The goal of this project is to estimate carbon export at the Axial Seamount in the N. Pacific (46 N, 131 W). The surface ocean is represented as a simple two-layer box model for oxygen and nitrate and known metabolic ratios are used to convert between nitrate, oxygen, and carbon. Data from the Ocean Observatories Initiative (OOI) Cabled Array is combined with University Corporation for Atmospheric Research (UCAR) current data and World Ocean Data (WOD) surface ocean concentrations for estimates. Annual carbon export at the Axial Seamount was found to be 0.9±0.4 mol/m^2/yr for 2015, ~3 times lower than estimates at the Hawaii Ocean Time‐series (HOT), Ocean Station Papa (OSP), and the Bermuda Atlantic Time‐series Study (BATS), but agreeing with estimates from closer to our study site. Additional uncertainty that is more difficult to quantify stems from failure to include bubble flux and eddy diffusion, however the comparable estimate of annual carbon export to past estimates suggests the efficacy of techniques used.