DOI: 10.1029/2018JC013750
Scopus记录号: 2-s2.0-85050819273
论文题名: Global Observations of Horizontal Mixing from Argo Float and Surface Drifter Trajectories
作者: Roach C.J. ; Balwada D. ; Speer K.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 7 起始页码: 4560
结束页码: 4575
语种: 英语
英文关键词: Argo floats
; drifters
; isopycnal mixing
; Lagrangian methods
英文摘要: Mixing by mesoscale eddies in the ocean plays a major role in setting the distribution of oceanic tracers, with important implications for physical and biochemical systems at local to global scales. Roach et al. (2016; https://doi.org/10.1002/2015JC011440) demonstrated that a two-particle analysis of Argo trajectories produces robust estimates of horizontal mixing in the Southern Ocean. Here we extend this analysis to produce global 1° × 1° maps of eddy diffusivity at the nominal Argo parking depth of 1,000 m. We also applied this methodology to estimate surface eddy diffusivities from Global Drifter Program (GDP) surface drifters. The global mean eddy diffusivity was 543 ± 155 m2/s at 1,000 m and 2637 ± 311 m2/s at the surface, with elevated diffusivities in regions of enhanced eddy kinetic energy, such as western boundary currents and along the Antarctic Circumpolar Current. The eddy kinetic energy at the equator is high at both the surface and depth, but the eddy diffusivity is only enhanced near the surface. At depth the eddy diffusivity is strongly suppressed due to the presence of mean flow. We used our observational estimates to test the validity of an eddy diffusivity parameterization that accounts for mixing suppression in the presence of zonal mean flows. Our results indicated that this parameterization generally agrees with the directly observed eddy diffusivities in the midlatitude and high-latitude oceans. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113660
Appears in Collections: 气候减缓与适应
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作者单位: Institute for Marine and Antarctic Studies and ARC Centre of Excellence for Climate System Science, University of Tasmania, Hobart, TAS, Australia; Courant Institute of Mathematical Sciences, New York University, New York, NY, United States; Geophysical Fluid Dynamics Institute, and Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, United States
Recommended Citation:
Roach C.J.,Balwada D.,Speer K.. Global Observations of Horizontal Mixing from Argo Float and Surface Drifter Trajectories[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(7)