Journal of Coastal Research SI 39 656 - 659 ICS 2004 (Proceedings) Brazil ISSN 0749-0208 FARACO, K. R.; ABREU DE CASTILHOS, J. and HORN FILHO, N. O., 2006. Morphodynamic aspects and El Niño oscillations in Ingleses beach, Santa Catarina Island, Southern Brazil. Journal of Coastal Research, SI 39 (Proccedings of the 8th International Coastal Symposium), 656 - 659. Itajaí, SC, Brazil, ISSN 0749-0208. The beach, characterized by dissipative to intermediate morphology, is located at the northeast part of island, on the southern Brazilian coast. With a parabolic planform orientated northwest-southeast, the study area is sheltered from the south and southeast swell associated with cold fronts passage in the region and mainly exposed to east swell action, generated by the blockage of these frontal systems. Two set of beach profile data obtained in 1996/1997 and 2000/2001, characterized respectively by influence of and oscillations showed a distinctive behaviour in relation to the beach processes, with a larger mobilization of beach sediments in the first period and a lesser beach volume variation in the second one. Observed variations between the two periods could be related to changes in atmospheric processes associated with El Niño Southern Oscillation (ENSO) cycle. During years, the subtropical jet intensity increases and results in a more frequent blockage to front systems that arrive on the Brazilian south coast, remaining motionless. Such situation is favorable to east swell formation, which originates storm waves in the region. During period, the subtropical jet loses intensity, allowing a quicker passage of cold front systems, which are normally responsible for the south and southeast swell. In this case, the beach is less affected, due to low exposition to these wave conditions related to its planimetric shape and general orientation. Ingleses Santa Catarina El Niño La Niña , El Niño La Niña Ingleses Beach profiles,ENSO, Brazilian beaches. ADDITIONAL INDEX WORDS: ABSTRACT Morphodynamic Aspects and El Niño Oscillations in Ingleses Beach, Santa Catarina Island, Southern Brazil K. R. Faraco; J. A. de Castilhos and N. O. Horn Filho INTRODUCTION Inter annual and large scale variations in the sediment volume of the beaches have been reported in several parts of the world. One of the main hypothesis pointed out to explain the occurrence of more intense erosive processes in certain periods is associated with El Niño Southern Oscillation (ENSO). Several papers in the international literature have attributed the erosion/deposition cycles to the negative ENSO (El Niño), or to the positive ENSO (La Niña) as . (2000), (2001), A and (2002), and (2003). On Santa Catarina's northern coastline, and (2000) studied the Itapoá's beaches and established a comparison between the coastline position, sediment volume variation and the sea surface temperature anomalies in the Equatorial Pacific Ocean from august/1996 to march/2000. The authors observed that the coastline recession and the beach erosion had been bigger between February/1997 and February/1998, concomitant with El Niño event. In the beaches of Santa Catarina's Island, (1998) had already pointed out the influence of El Niño in the erosive episode occurred between March and May of 1998 in the Ingleses beach. Although there seems to be a consensus about the influence of El Niño and La Niña events on the morpho-sedimentary processes of the beaches, little is known about this matter. It should be considered that the ENSO causes different changes in the atmospheric dynamics around the world, therefore their effects on the coastal zone cannot be generalized. Thus, a regional analysis is necessary to have a better comprehension of their impact on determined area. The aim of this paper is to evaluate the oscillations of the morphodynamic processes of a sandy beach located on the central coast of the Santa Catarina State, on the Brazilian southern coast, and their relationship with the El Niño/La Niña events, between 1996 and 2001. STORLAZZI TREMBANIS LLAN KOMAR ARCINIEGA SOUZA ANGULO CRUZ et al et al. On southern and southeastern Brazilian coast an intensification of the wave energy and a major occurrence of storm waves is equally associated to El Ninõ events. . (2001) referring to the coast of Rio Grande do Sul, the magnitude of storms to the occurrence of El Niño/La Niña events. M and (2000) noticed significant variations in the sand grain size on the beach of Bertioga, coast of São Paulo State, attributing this fact to the very intense El Niño action during the winter of 1997. N (2000) also attributed to El Niño an important shoreline recession in the Pontal do Paraná beach from 1997 to 1999. TOZZI ARTINS MAHIQUES OERNBERG et al STUDY AREA The Ingleses beach, nearly 5km long, is situated in the northeastern part of Santa Catarina island (Figure 1). This beach presents a northwest-southeast- oriented parabolic planform with a headland at the southeast sector. The study area is composed by quartzose fine sand, originated from the continental shelf and an important coastal dune system, situated at the southeast side, between Santinho and the Ingleses beaches. The dominant south winds in that region transport the eolic sand to the north, and promote the by-passing of sediments between these two beaches (A de C ., 1995). BREU ASTILHOS et al The local tide is semi-diurnal and microtidal type with a mean range around 1.0m. The wave climate in the region is predominantly represented by the incidence of southeast and east swells, associated with the passage of cold fronts in the region and northeast wave incidence for sea conditions (A , 1996). The study area is sheltered from the south and southeast swells, and it is mainly exposed to the east swell action, generated by the blockage of frontal systems. The beach profile can show dissipative to intermediate morphology, according to the methodology proposed by K (1997). The beach width increases from southeast to northwest, ... LVES LEIN Departamento de Geociências Universidade Federal de Santa Catarina, Florianópolis CEP. 88040-900 SC Brazil kfaraco@hotmail.com janete.abreu@cfh.ufsc.br horn@cfh.ufsc.br Journal of Coastal Research Special Issue 39, 2006 ,