Nitrous Oxide in the eastern tropical North Pacific

Abstract

[Author's abstract] Nitrous oxide (N2O) is an important greenhouse gas and is currently the most important ozone-depleting anthropogenic emission. However, its atmospheric budget is not well quantified, although it is well understood that the ocean is an important natural source of N2O to the atmosphere. Eastern-boundary ocean-upwelling zones containing large zones of oxygen-depleted intermediate waters, like the eastern tropical North Pacific (ETNP), are large sources of N2O to the atmosphere but they have not been adequately studied. I investigated the concentration of N2O between 20°N and 32.5°N in the ETNP aboard the R/V Thompson during March 17 – 27 2012. Surface waters were close to saturation between 22°N and 32.5°N and highly supersaturated at stations south of 22°N indicating a large source of N2O to the atmosphere south of 22°N.