title: Observing mesoscale eddy effects on mode-water subduction and transport in the North Pacific.
abstract: While modelling studies suggest that mesoscale eddies strengthen the subduction of mode waters, this eddy effect has never been observed in the field. Here we report results from a field campaign from March 2014 that captured the eddy effects on mode-water subduction south of the Kuroshio Extension east of Japan. The experiment deployed 17 Argo floats in an anticyclonic eddy (AC) with enhanced daily sampling. Analysis of over 3,000 hydrographic profiles following the AC reveals that potential vorticity and apparent oxygen utilization distributions are asymmetric outside the AC core, with enhanced subduction near the southeastern rim of the AC. There, the southward eddy flow advects newly ventilated mode water from the north into the main thermocline. Our results show that subduction by eddy lateral advection is comparable in magnitude to that by the mean flow--an effect that needs to be better represented in climate models.
authors.affiliation: Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, China.
authors.forename: Lixiao
authors.initials: L
authors.lastname: Xu
authors.affiliation: Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, China.
authors.forename: Peiliang
authors.initials: P
authors.lastname: Li
authors.affiliation: Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, China.|Scripps Institution of Oceanography, University of California San Diego, La Jolla, California 92093, USA.
authors.forename: Shang-Ping
authors.initials: SP
authors.lastname: Xie
authors.affiliation: Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, China.
authors.forename: Qinyu
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, China.
authors.forename: Cong
authors.initials: C
authors.lastname: Liu
authors.affiliation: Physical Oceanography Laboratory/Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao 266100, China.
authors.forename: Wendian
authors.initials: W
authors.lastname: Gao
references.citation: Nature. 2002 Dec 5;420(6915):489-93
references.pmid: 12487116
references.citation: Science. 2011 Oct 21;334(6054):328-32
references.pmid: 21921157
references.citation: Proc Natl Acad Sci U S A. 1979 Jul;76(7):3051-5
references.pmid: 16592670
references.citation: Science. 2014 Jul 18;345(6194):322-4
references.pmid: 25035491
references.citation: Science. 1997 Feb 7;275(5301):805-7
references.pmid: 9012341