DOI: 10.1002/2017JC013428
Scopus记录号: 2-s2.0-85043359355
论文题名: Diagnostic Characteristics of Submesoscale Coastal Surface Currents
作者: Soh H.S. ; Kim S.Y.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 3 起始页码: 1838
结束页码: 1859
语种: 英语
英文关键词: decay slopes
; high-frequency radar
; injection scales
; observational resource
; statistical decomposition
; surface currents
Scopus关键词: anisotropy
; coastal current
; decomposition analysis
; flux measurement
; frontogenesis
; map
; mesoscale eddy
; mesoscale motion
; mixed layer
; radar
; seasonal variation
; spectrum
; California
; San Diego
; United States
英文摘要: Submesoscale kinetic energy (KE) spectra and fluxes at the length scales ranging from 2 to 25 km are estimated from hourly and O(1) km-scale coastal surface current maps observed from shore-based high-frequency radars off southern San Diego. The one-dimensional wave number-domain KE spectra of the surface currents have decay slopes between k-2 and k-3 at a wave number (k) of 0.5 km−1. The KE spectra exhibit anisotropy associated with anisotropic circulation, which is constrained by the shoreline and bottom bathymetry. Moreover, the KE spectra exhibit weak seasonality related to the regional submesoscale eddies and low-frequency circulation with weak seasonal variability. The estimated KE fluxes are categorized into four cases of purely forward cascades and inverse cascades at all wave numbers, inverse-then-forward cascades with a single zero-crossing within the range of wave numbers (0.04 to 0.5 km−1), and residuals, which account for approximately 33%, 39%, 19%, and 9% of the total number of realizations, respectively. An injection scale where forward enstrophy cascade and inverse energy cascade occur is estimated to be 5 to 10 km from the cases of the inverse-then-forward cascade, which is consistent with the length scales of the regional submesoscale eddies. Thus, the regional submesoscale processes are initiated by surface frontogenesis due to the weak seasonal low-frequency surface circulation and topography-related currents, then maintained by baroclinic instabilities associated with the seasonal mixed layer and O(10) km-scale submesoscale eddies with weak seasonal variability. © 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/114306
Appears in Collections: 气候减缓与适应
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作者单位: Environmental Fluid Mechanics Laboratory, Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Yuseong-gu, Daejeon, South Korea
Recommended Citation:
Soh H.S.,Kim S.Y.. Diagnostic Characteristics of Submesoscale Coastal Surface Currents[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(3)