Hydrodynamics in Mobile Bay, Oxygen Mixing, and Hurricanes

Jeff Coogan
Postdoc Investigator

Dept. of Marine Chemistry and Geochemistry

Friday, Nov. 6, 2020, 3:10pm

Hydrodynamics in Mobile Bay: The complex interactions of tides, river discharge, and wind can make predicting salinity changes, currents, and physical interactions in estuaries difficult. Theoretical approaches are continually being refined in light of new data based on how to best simplify, parameterize, and understand estuarine physical dynamics. Long-term data sets provide significant insight into these complex interactions through a wide range of time series analysis methods. In Mobile Bay, river discharge is the main forcing condition driving seasonal changes in salinity flux and estuary length. At shorter time scales, the wind can be a dominant forcing condition that drives large changes in this estuary. Dissolved Oxygen mixing: Dissolved oxygen dynamics in the water column can be highly variable due to a number of physical and bio-chemical drivers. Improving our measurement capabilities of these drivers is critical to better understanding anthropogenic changes in our oceans. One of the components of the oxygen budget is the benthic flux, where oxygen is exchanged across the seafloor. Multiple methods can be used to quantify this flux but each has advantages, and weakness and understanding bottom boundary layer dynamics is key to improving how we sample oxygen at this boundary. Hurricanes: A quick look at two hurricane studies provides insight for: challenges measuring changes in the coastal zone and thinking about climate change and future storms.


Jeff Coogan is a postdoc at the Woods Hole Oceanographic Institution where he is working with Matt Long on developing a long-term eddy covariance mooring, as well as engineering other systems that help close the dissolved oxygen budget. Jeff attended the Florida Institute of Technology where he received his bachelor’s degree in Marine Biology and master’s degree in Coastal Engineering. After finishing his master's in 2013 he worked as a coastal engineer for a consulting firm on projects in California and Alaska. The engineering work included coastal armoring construction projects, monitoring and inspections of existing structures, and beach and nearshore survey work. In 2015, he decided to return to school to focus on a research career, and attended the University of South Alabama and Dauphin Island Sea Lab working with Brian Dzwonkowski. His PhD work focused on hydrodynamics in Mobile Bay and helped advance our understanding of forcing conditions in microtidal estuaries and local understanding of the estuary for interdisciplinary work.