A multiparametric method of interpolation using WOA05 applied to anthropogenic CO2 in the Atlantic

Abstract

This paper describes the development of a multiparametric interpolation method and its application to anthropogenic carbon (C_ANT) in the Atlantic, calculated by two estimation methods using the CARINA database. The multiparametric interpolation proposed uses potential temperature (θ), salinity, conservative ‘NO’ and ‘PO’ as conservative parameters for the gridding, and the World Ocean Atlas (WOA05) as a reference for the grid structure and the indicated parameters. We thus complement CARINA data with WOA05 database in an attempt to obtain better gridded values by keeping the physical-biogeochemical sea structures. The algorithms developed here also have the prerequisite of being simple and easy to implement. To test the improvements achieved, a comparison between the proposed multiparametric method and a pure spatial interpolation for an independent parameter (O₂) was made. As an application case study, C_ANT estimations by two methods (φC_Tº and TrOCA) were performed on the CARINA database and then gridded by both interpolation methods (spatial and multiparametric). Finally, a calculation of C_ANT inventories for the whole Atlantic Ocean was performed with the gridded values and using ETOPO2v2 as the sea bottom. Thus, the inventories were between 55.1 and 55.2 Pg-C with the φC_Tº method and between 57.9 and 57.6 Pg-C with the TrOCA method.