title: Improvement of ocean state estimation by assimilating mapped Argo drift data.
abstract: We investigated the impact of assimilating a mapped dataset of subsurface ocean currents into an ocean state estimation. We carried out two global ocean state estimations from 2000 to 2007 using the K7 four-dimensional variational data synthesis system, one of which included an additional map of climatological geostrophic currents estimated from the global set of Argo floats. We assessed the representativeness of the volume transport in the two exercises. The assimilation of Argo ocean current data at only one level, 1000 dbar depth, had subtle impacts on the estimated volume transports, which were strongest in the subtropical North Pacific. The corrections at 10(°)N, where the impact was most notable, arose through the nearly complete offset of wind stress curl by the data synthesis system in conjunction with the first mode baroclinic Rossby wave adjustment. Our results imply that subsurface current data can be effective for improving the estimation of global oceanic circulation by a data synthesis.
authors.affiliation: Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima 2-15, Yokosuka, Kanagawa 237-0061, Japan.
authors.forename: Shuhei
authors.identifier: 0000-0001-6157-0101
authors.initials: S
authors.lastname: Masuda
authors.affiliation: Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima 2-15, Yokosuka, Kanagawa 237-0061, Japan.
authors.forename: Nozomi
authors.identifier: 0000-0001-6634-1340
authors.initials: N
authors.lastname: Sugiura
authors.affiliation: Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima 2-15, Yokosuka, Kanagawa 237-0061, Japan.
authors.forename: Satoshi
authors.identifier: 0000-0002-5042-7729
authors.initials: S
authors.lastname: Osafune
authors.affiliation: Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Natsushima 2-15, Yokosuka, Kanagawa 237-0061, Japan.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Doi
mesh_terms: D008962:Models, Theoretical; D009792:Oceans and Seas; D014872:Water Movements