Adrian Mikhail Palaci Garcia


Adviser: Rocky Geyer

PhD Candidate, Applied Ocean Science & Engineering, MIT-WHOI Joint Program

BS, Civil Engineering (2016), University of Pittsburgh

About

CV

I am a PhD candidate in the MIT-WHOI Joint Program in Applied Ocean Science & Engineering studying Environmental Fluid Mechanics in the coastal zone. Through my research, I aim to understand environmental processes and dynamics, particuarly as they relate to sustainable managment of the coastal ocean. Furthermore, I am passionate about improving STEM representation and access to historically excluded groups through mentorship and educational outreach.

Research Interests

I use observational and numerical techniques to study the role of topographic features on hydrodynamics and circulation in estuaries. Ultimately, by linking physical mechanisms to biological and geochemical processes, I seek to contribute towards coastal sustainability and restoration efforts with a focus on nature-based solutions. There is beauty in the simplicity and functionality of nature, a design built on over 4 billion years of trial-and-error. It is imperative that we understand and capture these natural designs to work with them, rather than against them, as we consider the future of coastal infrastructure and management.

Current Projects

In classic river literature, flow around a bend is directed toward the outer bend at the surface and towards the inner bend at depth, owing to the lateral momentum balance between the centrifugal force and the pressure gradient resulting from the lateral setup. However, in estuaries, salinity differences along and across the channel also affect the hydrodynamics. During a field campaign led by Dr. Wouter Kranenburg, we observed classical lateral circulation during ebb tide and reversed lateral circulation during most of the flood tide. This reversed flow mechanism may have implications on estuarine channel morphodynamics, which is important for understanding the resiliency of estuaries with respect to anthropologic effects such as rising sea levels due to climate change.

Over long periods of time, the salinity distribution in an estuary is determined by the balance between river outflow, which advects salt out of the estuary, and estuarine dispersion, which is a diffusive mechanism bringing salt into the estuary. While we can determine the estuarine dispersion rate based on the river outflow and salinity time-series in an estuary, we need higher resolution spatial and temporal data to resolve the individual mechanisms that contribute to the total dispersion rate. We conducted a field campaign to determine the contribution of tidal tributary creeks to the total estuarine dispersion. In the system we studied, the creeks can account for about half of the total estuarine dispersion rate. The estuarine dispersion is important because it controls the salinity intrusion, which acts as a control on both ecology and freshwater sources.

In short, tidally-dominated estuaries, circulation and mixing is dominated by processes which act on a tidally-varying timescale (<12 hours) rather than on a tidally averaged (>12 hours). Using an idealized model built with the Regional Ocean Modeling System (ROMS), I applied a semi-Lagrangian to analyze dispersive salt fluxes and determine the relative contributions of various topographic regions to the the estuarine salt balance. Notably, by using a semi-Lagrangian approach, I quantify how dispersive processes outside the mouth of an estuary drive the salt flux inside the estuary. This research therefore provides a direct linkage between mixing and circulation patterns in an estuary and the coastal ocean.

Undergraduate Projects

With climate change and increased anthropologic activities on the rise, coastline environments and communities will face higher threats. Researchers are considering many forms of "green infrastructure" to protect against storm surge, including coral reefs, seagrasses, and mangrove trees. Mangroves dissipate wave energy because of flow through their complex prop root system, which effectively enhances turbulent dissipation. Working with Dr. Heidi Nepf, I conducted lab experiments to determine the drag coefficient of mangrove trees. The drag coefficient is important to calibrate numerical models that can be used to plan future mangrove reforestation projects.

This research was conducted with Dr. Jorge Abad. Analyzing satellite imagery on with ArcGIS, I worked to create a baseline study for the morphodynamics of the Peruvian Amazon River by performing a spatial and temporal analysis of the river system from 1985-2010. The purpose of this research is to understand the migration of the river and the processes that form the river's unique geomorphic characteristics. During the CREAR-ED-SPA course, I learned more about the importance of the river to the surrounding region.This research will be important for future development in the Amazon region, because the migration of the river will have huge implications on navigation and accessibility.

My senior design group worked in partnership with Lisa Hollingsworth-Segedy from the Pittsburgh Office of the American Rivers organization to perform the design work necessary for the permitting process to remove the Franklin-Glass Dam in Renfrew, PA. This dam, located on Connoquenessing Creek just downstream of the junction with Thorn Creek, is being removed to restore the river to free-flow conditions, allowing for improved fish passage and sediment transport. This project was incredibly multi-disciplinary, requiring work in hydraulics, ecology, environmental engineering, and construction management. My team worked with scientists and engineers from the PA Fish & Boat Commission and the PA Department of Environmental Protection to satisfy permitting requirements.

Publications

Journals

  1. (in preparation) A. M. P. Garcia and W. R. Geyer. "Nonlocal dispersion dominates the salt balance in short estuaries."
  2. A. M. P. Garcia, W. R. Geyer, and N. Randall. "Exchange flows in tributary creeks enhance dispersion by tidal trapping," Estuaries and Coasts, 2021. DOI: 10.1007/s12237-021-00969-4. [Online]. Available: https://link.springer.com/10.1007/s12237-021-00969-4.
  3. W. M. Kranenburg, W. R. Geyer, A. M. P. Garcia, and D. K. Ralston, “Reversed lateral circulation in a sharp estuarine bend with weak stratification.,” Journal of Physical Oceanography, 2019. DOI: 10.1175/JPO-D-18-0175.1. [Online]. Available: http://journals.ametsoc.org/doi/10.1175/JPO-D-18-0175.1.
  4. M. Maza, K. Adler, D. Ramos, A. M. P. Garcia, and H. M. Nepf, “Velocity and drag evolution from the leading edge of a model mangrove forest,” Journal of Geophysical Research: Oceans, vol. 122, no. 11, pp. 1–22, 2017. DOI: 10.1002/2017JC012945. [Online]. Available: http://doi.wiley.com/10.1002/2017JC012945.

Conference Papers

  1. S. J. Dickerson, S. P. Jacobs, A. M. P. Garcia, and D. V. P. Sanchez, “Joint assessment and evaluation of senior design projects by faculty and industry,” Proceedings - Frontiers in Education Conference, FIE, pp. 1–7, 2016. DOI: 10.1109/FIE.2016.7757395.

Conference Talks

  1. Garcia, A. M. P. & Geyer, W. R. Dispersion by tidal trapping is enhanced by stratification. Ocean Science (San Diego, California, 2020).
  2. Garcia, A. M. P. & Nepf, H. M. An experimental study of an artificial mangrove forest: Determination of drag and turbulence. Society of Hispanic Professional Engineers - Engineering Science Symposium (Seattle, WA, 2016).
  3. Garcia, A. M. P. & Abad, J. D. La evolucion morfodinamica del Rio Amazonas peruano: Un analisis planimetrico. Congreso Lationamericano de Hidraulica. (Lima, Peru, 2016). (Spanish)

Posters

  1. A. M. P. Garcia, N. Randall, W. R. Geyer, W. Kranenburg, and D. K. Ralston, “Effect of Tributary Creeks on Estuarine Dispersion,” in American Geophysical Union, Washington, D.C., USA, 2018.
  2. A. M. P. Garcia, J. D. Abad, C. Ortals, and C. E. Frias, “Insight on the Peruvian Amazon River: A Planform Metric Characterization of its Morphodynamics,” in River, Coastal and Estuarine Morphodynamics, Iquitos, Peru, 2015.
  3. A. M. P. Garcia, J. D. Abad, C. Ortals, and C. E. Frias, “Insight on the Peruvian Amazon River: A Planform Metric Characterization of its Morphodynamics,” in American Geophysical Union, San Francisco, California, 2014.

Diversity

During my career journey, my involvement in diversity programs has been and continues to be integral to my development. Through these programs, I encountered mentorship, support, relationships, and opportunities that have defined my experience. I value diversity because of the perspectives I have learned from embracing the collective experience I have had with my peers and mentors alike.

Contact

garciaap (at) mit.edu | Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA 02139