Role of shelf geometry and wave breaking in single N-type tsunami runup under geophysical-scale

2019 ◽  
Vol 138 ◽  
pp. 13-22
Author(s):  
Dae-Hong Kim ◽  
Sangyoung Son
Keyword(s):  
2017 ◽  
Vol 74 (6) ◽  
pp. 1735-1755 ◽  
Author(s):  
Erik T. Swenson ◽  
David M. Straus

Abstract The occurrence of boreal winter Rossby wave breaking (RWB) along with the quantitative role of synoptic transient eddy momentum and heat fluxes directly associated with RWB are examined during the development of Euro-Atlantic circulation regimes using ERA-Interim. Results are compared to those from seasonal reforecasts made using the Integrated Forecast System model of ECWMF coupled to the NEMO ocean model. The development of both Scandinavian blocking and the Atlantic ridge is directly coincident with anticyclonic wave breaking (AWB); however, the associated transient eddy fluxes do not contribute to (and, in fact, oppose) ridge growth, as indicated by the local Eliassen–Palm (EP) flux divergence. Evidently, other factors drive development, and it appears that wave breaking assists more with ridge decay. The growth of the North Atlantic Oscillation (NAO) in its positive phase is independent of RWB in the western Atlantic but strongly linked to AWB farther downstream. During AWB, the equatorward flux of cold air at upper levels contributes to a westerly tendency just as much as the poleward flux of momentum. The growth of the negative phase of the NAO is almost entirely related to cyclonic wave breaking (CWB), during which equatorward momentum flux dominates at jet level, yet low-level heat fluxes dominate below. The reforecasts yield realistic frequencies of CWB and AWB during different regimes, as well as realistic estimates of their roles during development. However, a slightly weaker role of RWB is simulated, generally consistent with a weaker anomalous circulation.


1998 ◽  
Vol 55 (17) ◽  
pp. 2852-2873 ◽  
Author(s):  
Manuel S. F. V. de Pondeca ◽  
Albert Barcilon ◽  
Xiaolei Zou

2018 ◽  
Vol 6 (2) ◽  
pp. 100 ◽  
Author(s):  
Nana Kariada Tri Martuti ◽  
Sri Mulyani Endang Susilowati ◽  
Wahid Akhsin Budi Nur Sidiq ◽  
Ditha Prasisca Mutiatari

The coastal area of Semarang City has a strategic function for regional economic development. Due to land use change, the environmental quality of coastal area is damaged and declining. The environmental quality decline has affected the socio-economic quality of local community. This research aims to investigate the role of local community in sustainable environmental management in Semarang City coastal area. The study takes place in two kelurahans, namely Tugurejo and Mangunharjo, and applies a descriptive qualitative approach to figure out the local community role in the coastal environment rehabilitation. Data collection through a preliminary survey supported with a satellite imagery study covers up an appropriate ecosystem with the research substance. Then the following data analysis and interpretation uses Miles and Huberman interactive analysis method. The results show the significant role of the local community in coastal area quality management and improvement in Semarang City more effectively and efficiently. This relates to their active interactions in various community-based programs including wave-breaking instrument building and mangrove nursery and planting.


2000 ◽  
Vol 413 ◽  
pp. 181-217 ◽  
Author(s):  
JOHN GRUE ◽  
ATLE JENSEN ◽  
PER-OLAV RUSÅS ◽  
J. KRISTIAN SVEEN

Solitary waves propagating horizontally in a stratified fluid are investigated. The fluid has a shallow layer with linear stratification and a deep layer with constant density. The investigation is both experimental and theoretical. Detailed measurements of the velocities induced by the waves are facilitated by particle tracking velocimetry (PTV) and particle image velocimetry (PIV). Particular attention is paid to the role of wave breaking which is observed in the experiments. Incipient breaking is found to take place for moderately large waves in the form of the generation of vortices in the leading part of the waves. The maximal induced fluid velocity close to the free surface is then about 80% of the wave speed, and the wave amplitude is about half of the depth of the stratified layer. Wave amplitude is defined as the maximal excursion of the stratified layer. The breaking increases in power with increasing wave amplitude. The magnitude of the induced fluid velocity in the large waves is found to be approximately bounded by the wave speed. The breaking introduces a broadening of the waves. In the experiments a maximal amplitude and speed of the waves are obtained. A theoretical fully nonlinear two-layer model is developed in parallel with the experiments. In this model the fluid motion is assumed to be steady in a frame of reference moving with the wave. The Brunt-Väisälä frequency is constant in the layer with linear stratification and zero in the other. A mathematical solution is obtained by means of integral equations. Experiments and theory show good agreement up to breaking. An approximately linear relationship between the wave speed and amplitude is found both in the theory and the experiments and also when wave breaking is observed in the latter. The upper bound of the fluid velocity and the broadening of the waves, observed in the experiments, are not predicted by the theory, however. There was always found to be excursion of the solitary waves into the layer with constant density, irrespective of the ratio between the depths of the layers.


2009 ◽  
Vol 39 (9) ◽  
pp. 2077-2096 ◽  
Author(s):  
Caroline J. Muller ◽  
Oliver Bühler

Abstract As part of an ongoing effort to develop a parameterization of wave-induced abyssal mixing, the authors derive an heuristic model for nonlinear wave breaking and energy dissipation associated with internal tides. Then the saturation and dissipation of internal tides for idealized and observed topography samples are investigated. One of the main results is that the wave-induced mixing could be more intense and more confined to the bottom than previously assumed in numerical models. Furthermore, in this model wave breaking and mixing clearly depend on the small scales of the topography below 10 km or so, which is below the current resolution of global bathymetry. This motivates the use of a statistical approach to represent the unresolved topography when addressing the role of internal tides in mixing the deep ocean.


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