small plume dispersion

Photo of the Tijuana River plume in Imperial Beach, CA courtesy of WILDCOAST.

Photo of the Tijuana River plume in Imperial Beach, CA courtesy of WILDCOAST.

The connectivity between estuaries and the coastal ocean is important for the transport of sediments, nutrients, and contaminants.  Much scientific research has been focused on the estuary or the freshwater plume, with an emphasis on large river plumes, separately.  Less is known about how the two interact in the very nearshore environment, particularly regarding small river plumes. Grad student Angelica Rodriguez is investigating how small river plumes disperse in coastal waters.  Of primary interest is the impact of waves and wave-driven currents and turbulence in the surfzone. This work is motivated by water quality concerns from small contaminated rivers and storm drain outfalls. With funding from the Blasker-Rose-Miah Fund of The San Diego Foundation, Angelica is developing idealized numerical models to investigate these processes as well as the estuarine response to extreme events in terms of residence time.

Specifically, Angelica is developing her numerical model based on the Tijuana River Estuary (pictured), located on the US-Mexico border. This estuary is less developed in terms of physical infrastructure than many other Southern California Lagoons, yet experiences very poor water quality from upstream contamination. Nearby beaches are frequently closed due to contamination concerns. Thus, Angelica’s work seeks to help us better understand how these small plumes spread and impact coastal water quality. This work is related to an NSF project led by Falk Feddersen investigating dispersion of tracers along the coast and between the surfzone and inner-shelf: CSIDE – Cross Surfzone/Inner-shelf Dye Exchange.