Nearshore Costal Dynamics during Intense Winds: Local and Synoptic Scale Events

Nearshore coastal dynamics during intense winds events are investigated in the Northern Yucatan Peninsula. Understanding the hydrodynamics under local and synoptic scale events in this region is essential to predict sediment and pollution transport. The study area is characterized by a very wide continental shelf, a micro-tidal range, and the influence of easterly winds. Moreover, intense onshore winds associated with either local sea-breezes or synoptic scale cold-front passages are ubiquitous in this region. The wind speed during these events can exceed 15 m/s and play an important role in the coastal circulation. A field experiment was conducted during Spring 2014 (April 1^stto 12th) in order to investigate coastal dynamics from the inner shelf to swash, during local and synoptic scale events. Waves and currents were measured concurrently at different cross-shore locations (inner shelf, surf zone, swash zone) and are correlated with the different forcing mechanisms (i.e., wind, waves, and tides). A westward current is observed extending from the shelf to the swash zone during strong sea breeze events (>10 m/s from the northeast). The current magnitude increases towards shore, but can be related to different forcing mechanism depending on the cross-shore location. On the other hand, during the cold-front passage (storm event) circulation changes drastically with onshore current in the inner shelf, whereas strong undertow currents are observed inside the surf zone. Understanding the hydrodynamics under local and synoptic scale events is essential to predict sediment and pollution transport in the study area. This work was funded by the Instituto de Ingenieria UNAM, through the International Collaborative Research project with the University of Delaware, and the DGAPA UNAM (PAPIIT IN107315).