scholarly journals A model to predict the coastal sea level variations and surge

2009 ◽  
Author(s):  
M. M. F. de Oliveira ◽  
N. F. F. Ebecken

Considerable insight has recently been gained into the dynamics of continental-shelf circulation through a simplification of the governing equations, resulting in a parabolic equation for the pressure field. Solutions of this equation appear to model realistically important flow phenomena, notably the effects of winds and coastal geography in setting up half-open coastal circulation cells, and an associated trapped pressure field. Circulation cells should be established mainly on the inner shelf, according to theory, i.e. within about 30 km of the coast, and should be important agents of mass exchange. In the present paper the theory of shelf circulation is reviewed with an emphasis on its most general predictions. Then the question is examined of how a considerable body of evidence on coastal sea-level variations in response to wind, longshore sea-level gradients, longshore and cross-shore currents can be interpreted in the theoretical framework.


2019 ◽  
Vol 42 (4) ◽  
pp. 327-343 ◽  
Author(s):  
Huan-Chin Kao ◽  
Chung-Yen Kuo ◽  
Kuo-Hsin Tseng ◽  
C.K. Shum ◽  
Tzu-Pang Tseng ◽  
...  

2021 ◽  
Author(s):  
Fabio Mangini ◽  
Léon Chafik ◽  
Antonio Bonaduce ◽  
Laurent Bertino ◽  
Jan Even Øie Nilsen

Abstract. Sea-level variations in coastal areas can differ significantly from those in the nearby open ocean. Monitoring coastal sea-level variations is therefore crucial to understand how climate variability can affect the densely populated coastal regions of the globe. In this paper, we study the sea-level variability along the coast of Norway by means of in situ records, satellite altimetry data, and a network of eight hydrographic stations over a period spanning 16 years (from 2003 to 2018). At first, we evaluate the performance of the ALES-reprocessed coastal altimetry dataset by comparing it with the sea-level anomaly from tide gauges over a range of timescales, which include the long-term trend, the annual cycle and the detrended and deseasoned sea level anomaly. We find that coastal altimetry outperforms conventional altimetry products at most locations along the Norwegian coast. We later take advantage of the coastal altimetry dataset to perform a sea level budget along the Norwegian coast. We find that the thermosteric and the halosteric signals give a comparable contribution to the sea-level trend along the Norwegian coast, except for three, non-adjacent hydrographic stations, where salinity variations affect the sea-level trend more than temperature variations. We also find that the sea-level annual cycle is more affected by variations in temperature than in salinity, and that both temperature and salinity give a comparable contribution to the detrended and deseasoned sea-level along the entire Norwegian coast.


2019 ◽  
Vol 124 (3) ◽  
pp. 2196-2217 ◽  
Author(s):  
William J. Pringle ◽  
Juan Gonzalez‐Lopez ◽  
Brian R. Joyce ◽  
Joannes J. Westerink ◽  
Andre J. Westhuysen

1974 ◽  
Vol 28 (5) ◽  
pp. 524-530 ◽  
Author(s):  
G. W. Lennon

The use of mean sea level as a surface of reference that might provide an independent control for geodetic leveling has been a long term goal arising from the classical analogy between the geoid as an equipotential surface and the surface assumed by a hypothetical undisturbed world ocean. The problems associated with this aim are now known to be vast, and are associated with the dynamics of the marine system, notably its response to meteorological forces, to variations in density and to the effects of basic circulation patterns. In consequence the mean sea level surface varies rapidly in both time and space. This identifies in fact a distinctive scientific discipline, coastal geodesy, in which contributions are required by both geodesists and oceanographers. It has come to be recognized that the coastal zone is a hazardous environment for all observational techniques concerned. On the one hand, the difficulties of measurement of coastal sea levels have only recently been understood; on the other hand, precise leveling procedures are now known to be influenced by the attraction of marine tides and by crustal deformation of tidal loading. Much of the data available for study are therefore inadequate and, moreover, it should be noted that long-time series are required. It is now possible to lay plans for both geodetic and oceanographic procedures to remedy these deficiencies in the long-term interests of the study.


2006 ◽  
Vol 36 (11) ◽  
pp. 2173-2184 ◽  
Author(s):  
Holly F. Ryan ◽  
Marlene A. Noble

Abstract The amplitude of the frequency response function between coastal alongshore wind stress and adjusted sea level anomalies along the west coast of the United States increases linearly as a function of the logarithm (log10) of the period for time scales up to at least 60, and possibly 100, days. The amplitude of the frequency response function increases even more rapidly at longer periods out to at least 5 yr. At the shortest periods, the amplitude of the frequency response function is small because sea level is forced only by the local component of the wind field. The regional wind field, which controls the wind-forced response in sea level for periods between 20 and 100 days, not only has much broader spatial scales than the local wind, but also propagates along the coast in the same direction as continental shelf waves. Hence, it has a stronger coupling to and an increased frequency response for sea level. At periods of a year or more, observed coastal sea level fluctuations are not only forced by the regional winds, but also by joint correlations among the larger-scale climatic patterns associated with El Niño. Therefore, the amplitude of the frequency response function is large, despite the fact that the energy in the coastal wind field is relatively small. These data show that the coastal sea level response to wind stress forcing along the west coast of the United States changes in a consistent and predictable pattern over a very broad range of frequencies with time scales from a few days to several years.


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