Generation of shelf waves on the East Australian coast by wind stress

2008 ◽  
pp. 220-220
Author(s):  
B. V. Hamon
Keyword(s):  
Wind Stress ◽  
Shelf Waves

scholarly journals CHARACTERISING COASTAL SHELF WAVES ALONG THE NSW COAST

2020 ◽  
pp. 37
Author(s):  
Cristina Viola ◽  
Danielle Verdon-Kidd ◽  
Hannah Power
Keyword(s):  
Wind Stress ◽  
Tide Gauge ◽  
New South ◽  
Spatiotemporal Variability ◽  
Ocean Tide ◽  
Coastal Inundation ◽  
South Wales ◽  
Coastal Shelf ◽  
Shelf Waves ◽  
Great Australian Bight

New South Wales (NSW) often experiences periods of coastal inundation and estuarine flooding. One of the causal mechanisms of these episodes are coastal shelf waves (CSW), generated by synoptic disturbances (Church et al., 2006). CSWs in Australia often result from wind stress, mostly along mid-latitudes (e.g., the Great Australian Bight) and propagate anticlockwise (Woodham et al., 2013). However, there are no tools available for identifying and characterising CSWs and as such there is very little information on the magnitude, frequency, duration, and spatiotemporal variability. This paper aims to: (1) develop a method to identify and track CSWs using the existing ocean tide gauge network, (2) identify patterns in the frequency, duration, and magnitude of CSW, and (3) assess the factors that affect the frequency, duration, and magnitude of CSWs along the NSW coast.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/oigzYIKFBmA

scholarly journals Localised continental shelf waves: geometric effects and resonant forcing

2015 ◽  
Vol 785 ◽  
pp. 54-77 ◽  
Author(s):  
J. T. Rodney ◽  
E. R. Johnson
Keyword(s):  
Continental Shelf ◽  
Depth Profile ◽  
Wind Stress ◽  
Local Maximum ◽  
Far Field ◽  
Maximum Frequency ◽  
Offshore Structure ◽  
Shelf Wave ◽  
Shelf Waves ◽  
Continental Shelf Waves

Alongshore variations in coastline curvature or offshore depth profile can create localised regions of shelf-wave propagation with modes decaying outside these regions. These modes, termed localised continental shelf waves ($\ell$CSWs) here, exist only at certain discrete frequencies lying below the local maximum frequency, and above the far-field maximum frequency, for propagating shelf waves. The purpose of this paper is to obtain these frequencies and construct, both analytically and numerically, and discuss $\ell$CSWs for shelves with arbitrary alongshore variations in offshore depth profile and coastline curvature. If the shelf curvature changes by a small fraction of its value over the shelf section of interest or an alongshore perturbation in offshore depth profile varies slowly over the same length scale then $\ell$CSWs can be constructed using WKBJ theory. Two subcases are described: (i) if the propagating region is sufficiently long that the offshore structure of the $\ell$CSW varies appreciably alongshore then the frequency and alongshore structure are found from a sequence of local problems; (ii) if the propagating region is sufficiently short that the alongshore change in offshore structure of the $\ell$CSW is small then the alongshore modal structure is given in an explicit, uniformly valid form. A separate asymptotic theory is required for curvature perturbations to shelves that are otherwise straight rather than curved. Comparison with highly accurately numerically determined $\ell$CSWs shows that both theories are extremely accurate, with the WKBJ theory having a significantly wider range of applicability. An idealised model for the generation of $\ell$CSWs is also suggested. A localised time-periodic wind stress generates an evanescent continental shelf wave in the far field of a localised mode where the coast is almost straight and the response on the shelf is obtained numerically. If the forcing frequency is close to that of an $\ell$CSW then the wind stress excites energetic motions in the region of maximum curvature, creating a significant localised response possibly far from the forcing region.

FEATURES OF WIND FIELD OVER THE SEA SURFACE IN THE COASTAL AREA BASED ON SAR OBSERVATIONS

2017 ◽  
Author(s):  
Anna Monzikova ◽  
Anna Monzikova ◽  
Vladimir Kudryavtsev Vladimir ◽  
Vladimir Kudryavtsev Vladimir ◽  
Alexander Myasoedov ◽  
...  
Keyword(s):  
Wind Stress ◽  
Surface Wind ◽  
Quantitative Description ◽  
Energy Resource ◽  
Resource Assessment ◽  
Internal Boundary Layer ◽  
Offshore Wind ◽  
Internal Boundary ◽  
Sar Images ◽  
Surface Wind Stress

“Wind-shadowing” effects in the Gulf of Finland coastal zone are analyzed using high resolution Envisat Synthetic Aperture Radar (SAR) measurements and model simulations. These effects are related to the internal boundary layer (IBL) development due to abrupt change the surface roughness at the sea-land boundary. Inside the "shadow" areas the airflow accelerates and the surface wind stress increases with the fetch. Such features can be revealed in SAR images as dark areas adjacent to the coastal line. Quantitative description of these effects is important for offshore wind energy resource assessment. It is found that the surface wind stress scaled by its equilibrium value (far from the coast) is universal functions of the dimensionless fetch Xf/G. Wind stress reaches an equilibrium value at the distance Xf/G of about 0.4.

scholarly journals Using Eulerian and Lagrangian Approaches to Investigate Wind-Driven Changes in the Southern Ocean Abyssal Circulation

2013 ◽  
Vol 44 (2) ◽  
pp. 662-675 ◽  
Author(s):  
Paul Spence ◽  
Erik van Sebille ◽  
Oleg A. Saenko ◽  
Matthew H. England
Keyword(s):  
Southern Ocean ◽  
Wind Stress ◽  
Climate Model ◽  
Meridional Overturning Circulation ◽  
Global Ocean ◽  
Lagrangian Particle ◽  
Stress Changes ◽  
Abyssal Circulation ◽  
Flow Pathways ◽  
Ocean Wind

Abstract This study uses a global ocean eddy-permitting climate model to explore the export of abyssal water from the Southern Ocean and its sensitivity to projected twenty-first-century poleward-intensifying Southern Ocean wind stress. The abyssal flow pathways and transport are investigated using a combination of Lagrangian and Eulerian techniques. In an Eulerian format, the equator- and poleward flows within similar abyssal density classes are increased by the wind stress changes, making it difficult to explicitly diagnose changes in the abyssal export in a meridional overturning circulation framework. Lagrangian particle analyses are used to identify the major export pathways of Southern Ocean abyssal waters and reveal an increase in the number of particles exported to the subtropics from source regions around Antarctica in response to the wind forcing. Both the Lagrangian particle and Eulerian analyses identify transients as playing a key role in the abyssal export of water from the Southern Ocean. Wind-driven modifications to the potential energy component of the vorticity balance in the abyss are also found to impact the Southern Ocean barotropic circulation.

scholarly journals Seasonal variability of SST fronts and winds on the southeastern continental shelf of Brazil

2019 ◽  
Vol 69 (11-12) ◽  
pp. 1387-1399 ◽  
Author(s):  
Huan-Huan Chen ◽  
Yiquan Qi ◽  
Yuntao Wang ◽  
Fei Chai
Keyword(s):  
Continental Shelf ◽  
Wind Stress ◽  
Seasonal Variability ◽  
Detection Algorithm ◽  
Coupling Coefficients ◽  
Seafloor Topography ◽  
Wind Stress Curl ◽  
Large Coupling ◽  
The Impact ◽  
Sst Fronts

Abstract Fourteen years (September 2002 to August 2016) of high-resolution satellite observations of sea surface temperature (SST) data are used to describe the frontal pattern and frontogenesis on the southeastern continental shelf of Brazil. The daily SST fronts are obtained using an edge-detection algorithm, and the monthly frontal probability (FP) is subsequently calculated. High SST FPs are mainly distributed along the coast and decrease with distance from the coastline. The results from empirical orthogonal function (EOF) decompositions reveal strong seasonal variability of the coastal SST FP with maximum (minimum) in the astral summer (winter). Wind plays an important role in driving the frontal activities, and high FPs are accompanied by strong alongshore wind stress and wind stress curl. This is particularly true during the summer, when the total transport induced by the alongshore component of upwelling-favorable winds and the wind stress curl reaches the annual maximum. The fronts are influenced by multiple factors other than wind forcing, such as the orientation of the coastline, the seafloor topography, and the meandering of the Brazil Current. As a result, there is a slight difference between the seasonality of the SST fronts and the wind, and their relationship was varying with spatial locations. The impact of the air-sea interaction is further investigated in the frontal zone, and large coupling coefficients are found between the crosswind (downwind) SST gradients and the wind stress curl (divergence). The analysis of the SST fronts and wind leads to a better understanding of the dynamics and frontogenesis off the southeastern continental shelf of Brazil, and the results can be used to further understand the air-sea coupling process at regional level.

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