DOI: 10.1029/2017JC013539
Scopus记录号: 2-s2.0-85051114543
论文题名: Subseasonal Coastal-Trapped Wave Propagations in the Southeastern Pacific and Atlantic Oceans: 1. A New Approach to Estimate Wave Amplitude
作者: Illig S. ; Cadier E. ; Bachèlery M.-L. ; Kersalé M.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 6 起始页码: 3915
结束页码: 3941
语种: 英语
英文关键词: coastal-trapped waves
; eastern boundary upwelling systems
; linear coastal model
; modal decomposition
; ocean model simulations
; subseasonal variability
英文摘要: The Humboldt and the Benguela upwelling systems are connected to the equatorial variability through the coastal waveguide, so that a large variance of the coastal sea level and current variability can be described as an infinite sum of orthonormal free Coastal-Trapped Wave (CTW) modes. The objective of this study is to infer the CTW mode contributions to the coastal variability in both systems at subseasonal timescales (<120 days) from regional ocean circulation model simulations. We develop and validate twin regional model configurations of the southeastern Pacific and Atlantic Oceans. Cross-shore spatial structures of the first four free CTW modes are then derived from model mean stratification and topography along the southwestern African and South American continents. We introduce and validate a new methodology to estimate the gravest CTW mode contributions to model pressure and alongshore current. Our formulation draws on the orthonormality of the CTW modal structures, and uses a simple projection of the coastal and bottom model pressure onto each CTW structure. Results give confidence in the ability of this modal decomposition methodology to disentangle CTW mode contributions from complex nonlinear coastal processes that control the coastal subseasonal variability. In both systems, it allows to successfully extract the gravest poleward propagating CTW modes with velocities close to the theoretical values and amplitudes consistent with the solutions of a simple multimode linear CTW model. Furthermore, results show that both systems exhibit relatively different CTW dynamics and forcings which are discussed in the companion paper (Illig et al., 2018). © 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/113797
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: Laboratoire d'Etudes en Géophysique et Océanographie Spatiale (LEGOS), CNRS/IRD/UPS/CNES, Toulouse, France; Department of Oceanography, MARE Institute, LMI ICEMASA, University of Cape Town, Cape Town, South Africa; Nansen-Tutu Centre, Marine Research Institute, Department of Oceanography, University of Cape Town, Cape Town, South Africa; NOAA/Atlantic Oceanographic and Meteorological Laboratory, Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL, United States
Recommended Citation:
Illig S.,Cadier E.,Bachèlery M.-L.,et al. Subseasonal Coastal-Trapped Wave Propagations in the Southeastern Pacific and Atlantic Oceans: 1. A New Approach to Estimate Wave Amplitude[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(6)