Variability of Residence Time in Arctic Back-Barrier Estuaries
Along a quarter of the Beaufort Sea coast, back-barrier estuaries modulate the transport and transformation of nitrogen and carbon, impacting food webs and carbon budgets. It is unclear what effect rapid Arctic change will have on coastal biogeochemistry, partly because present-day spatial and temporal variability of residence time in Arctic back-barrier estuaries is unknown, which complicates efforts to predict future change. This study investigates the residence time of water in Arey, Kaktovik, and Jago Lagoons, three back-barrier estuaries along the Beaufort Sea coast of northern Alaska. Estimates of residence time based on the volume of the lagoon and river input suggest that residence time in the model domain range from less than one month to several months, depending on the river discharge. These preliminary results assume the estuary is not frozen and is in steady state. Ongoing work to investigate the spatial and temporal variability in residence time of water in these estuaries includes implementing a hydrodynamic numerical model, the Regional Ocean Modeling System (ROMS). The model accounts for processes including local winds, rivers, and larger scale circulation in 2019, and future work includes accounting for sea ice and waves, as well as validating the model. Analysis will focus on spatial and temporal variations in residence time and other circulation dynamics. Results will inform efforts to predict future coastal Arctic changes to circulation and carbon cycles.
Graduate student Atmospheric and Oceanic Sciences, CU Boulder