INVESTIGADORES
MARTIN Paula Beatriz
artículos
Título:
Are wind wave heights increasing in South-eastern South American Continental Shelf
Autor/es:
W. C. DRAGANI, P. B. MARTIN, C. G. SIMIONATO AND M. I. CAMPOS
Revista:
CONTINENTAL SHELF RESEARCH
Editorial:
Elsevier
Referencias:
Lugar: Amsterdam, Holanda; Año: 2010 vol. 30 p. 481 - 490
ISSN:
0278-4343
Resumen:
In this paper, a possible increase in wind wave heights in the South-easternSouth American Continental Shelf between 32°S and 40° is investigated. Both time seriesof in situ (1996–2006) and Topex/Poseidon (1993–2001) annual mean significant waveheights gathered at the continental shelf and adjacent ocean present apparent positivetrends. Even though these trends are not statistically different from zero, it must be takeninto account that the available in situ and satellite data have a short span and, moreover, insitu data present several gaps. Several papers presented evidences about a possible changein the low atmospheric circulation in this region of the Southern Hemisphere.Consequently, a weak increase in wave height might be occurring which would be hard toquantify due to the shortness and the insufficiency of the available observations. In order tostudy a possible trend in mean annual wind wave heights Simulating Waves Nearshore(SWAN) model forced with NCEP/NCAR surface wind was implemented in a regionaldomain for the period 1971-2005. The annual root-mean-square heights of the simulatedwave show significant trends at several locations of the inner continental shelf and theadjacent ocean. The most significant increase is observed between 1991-2000 and 1981-1990 decades. The largest difference (0.20 m, 9%) occurs around 34°S-48°W. The waveheight increase is somewhat lower, 7%, in the continental shelf and in the Río de la Plataestuary. The annual mean energy density (spatially averaged) also presents a significantpositive trend (0.036 m2/yr) and relatively high inter-annual variability. The possible linkbetween this inter-annual variability and El Niño - Southern Oscillation (ENSO) wasinvestigated but no apparent relationship was found. A possible increase in the annual meanenergy density raises two important issues to be considered. First, if change in the windpattern has occurred and it has been able to increase the mean wave height in the regionthen it is natural to think that an increase in the mean depth of the mixed layer of the oceanmight have occurred as well. Secondly, an increment in the wave density energy would beable to produce changes in the littoral processes and, consequently, in the erosion of thecoast. In this sense, an increase of the erosive processes along the sandy coast of BuenosAires province during the last thirty years has been previously reported