Atmospheric forcing and marsh dissolved organic matter fluxes: Modeling and observations from a Chesapeake Bay tidal marsh-estuary ecosystem
Atmospheric forcing and marsh dissolved organic matter fluxes: Modeling and observations from a Chesapeake Bay tidal marsh-estuary ecosystem
Abstract:
Biogeochemical processes on the fringes of estuaries are relatively unconstrained especially in terms of tidal marsh-estuary exchanges and carbon budgets. A three-dimensional biogeochemical simulation can be a valuable tool to augment the observations on these exchanges and can provide insights into the carbon fluxes and organic matter fate. The Finite Volume Community Ocean Model (FVCOM) coupled with CE-QUAL-ICM for water quality is used to simulate the physical and biogeochemical characteristics in the year 2005 for the Kirkpatrick Marsh and Rhode River, a sub-estuary of Chesapeake Bay, MD, USA. The Rhode River hydrodynamic simulation (rhodeFVM) accurately recreates the temperature and salinity in the shallow water sub-estuary and includes a marsh grass drag model that gives realistic marsh water flow. Data analysis from spring 2015 shows a strong negative correlation between marsh creek salinity and DOM fluxes, with wind velocity being an important factor driving large amplitude variation. Model results are consistent with observations revealing sub-tidal variability of marsh creek salinity associated with non-linear interactions between wind velocity and precipitation events. A newly developed three-dimensional marsh DOM model that includes chromophoric DOM provides insights into the spatial and temporal variability of DOM being exported to the estuary.