Nearshore Coastal Dynamics on a Sea-Breeze Dominated Micro-Tidal Beach (NCSAL)

Monday, 15 December 2014
Alec Torres-Freyermuth1, Jack Anthony Puleo2, Amaia Ruiz de Alegría-Arzaburu3, Jens Figlus4, Tonatiuh Mendoza1, Jose Carlos Pintado-Patino1, Aline Pieterse2, Patricia Chardon-Maldonado2, Nick Robert DiCosmo2, Nina Wellman4, Hector Garcia-Nava3, Leonardo Palemón-Arcos1, Tiffany Roberts5, José López-González1, Maurcio Bravo1, Elena Ojeda1, Gabriela Medellín1, Christian Mario Appendini1, Bernardo Figueroa1, Mariana González-Leija6, Cecilia Enriquez7, Adrián Pedrozo-Acuña8 and Paulo Salles1, (1)Universidad Nacional Autónoma de México, Institute of Engineering, Sisal, Mexico, (2)Univ of DE-Civil & Envir Engrg, Newark, DE, United States, (3)Univerisdad Autónoma de Baja California, Ensenada, Mexico, (4)Texas A & M University at Galveston, Galveston, TX, United States, (5)Florida Atlantic University, Boca Raton, FL, United States, (6)Axis Ingeniería, Merida, Mexico, (7)Universidad Nacional Autónoma de México, Facultad de Ciencias, Sisal, Mexico, (8)Universidad Nacional Autónoma de México, Institute of Engineering, Mexico, Mexico
A comprehensive field experiment devoted to the study of coastal processes on a micro-tidal beach was conducted from March 30th to April 12th 2014 in Sisal, Yucatán México. Wave conditions in the study area are controlled by local (i.e., sea-breezes) and meso-scale (i.e., Nortes) meteorological events. Simultaneous measurements of waves, tides, winds, currents, sediment transport, runup, and beach morphology were obtained in this experiment. Very dense nearshore instrumentation arrays allow us the study of the cross-/along- shore variability of surf/swash zone dynamics during different forcing conditions. Strong sea-breeze wind events produced a diurnal cycle with a maximum wind speed of 14 m/s. The persistent sea-breeze system forces small-amplitude (Hs<1 m) short-period (Tp<4 s) NE waves approaching with a high incidence wave angle. These wave conditions drive westward alongshore currents of up to 0.6 m/s in the inner surf zone and hence produce an active sediment transport in the swash zone. On the other hand, the more energetic (Hs>1 m) Norte event, lasting 48 hours, reached the coast on April 8th generating a long-period swell (Tp>10 s) arriving from the NNW. This event induced an eastward net sediment transport across a wide surf zone. However, long-term observations of sand impoundment at a groin located near the study area suggests that the net sediment transport in the northern Yucatan peninsula is controlled by sea-breeze events and hence swash zone dynamics play an important role in the net sediment budget of this region. A comparative study of surf and swash zone dynamics during both sea-breeze and Norte events will be presented. The Institute of Engineering of UNAM, throughout an International Collaborative Project with the University of Delaware, and CONACYT (CB-167692) provided financial support. The first author acknowledges ONR Global for providing financial support throughout the Visiting Scientist Program.