Modeling provides a powerful tool for synthesizing data and research, and providing the capability to predict responses of ecosystems to changing drivers.


PIE-FVCOM 3D Hydrodynamic Model
FVCOM is a 3D, primitive-equation, finite-volume hydrodynamic model developed by Changsheng Chen at UMass Dartmouth (see FVCOM). Current modeling is development of FVCOM for the Plum Island Estuaries that is coupled to the coastal zone and the Merrimack River. Liuzhi Zhao (UMass Dartmouth), Joe Vallino (MBL) and Changsheng Chen are the primary developers of PIE-FVCOM.

The image on the right is a simulation showing velocity field and flooding and drying of the marsh platform. The marsh topography data were obtained from a LIDAR flyover. Bathymetry data are based on GPS surveys of tidal creeks combined with NGDC bathymetry surveys. Click on the image to download an AVI movie (12.6 MB). The simulation uses an older modeling domain that does not include the Merrimack River and its connection to PI Sound via PI River.

Generalized Estuarine Metabolism Model
This model couples an aggregated food web model with a 1D, tidally averaged, advection-dispersion transport model and is being used to examine different nutrient and organic matter loading scenarios on estuarine food web dynamics.

2D Hydrodynamic Model
A 2D hydrodynamic model is being developed for the Plum Island Estuary. A diffusive wave approach is used to simplify the hyperbolic PDE and to couple in subsurface processes. The hydrodynamic model will drive a 2D advection-dispersion model that governs estuarine biogeochemistry. This work is on going.

Data Assimilation Modeling
Data assimilation is a technique in which data collected from field observations or experiments are used to improve model performance. Some examples applied to biogeochemical modeling are: Microbial Food Web and Estuarine Metabolism.

Maximum Entropy Production (MEP)
Theory: Biological systems organize to maximize entropy production subject to information and biophysicochemical constraints. ATB Experiment 1 - Cycling of energy input - This experiment examines the conjecture that living systems differ from inanimate systems, such as fire, in that they maximize entropy production averaged over some characteristic time scale appropriate to the system based on perturbations the system has evolved to cope with.

Marsh Equilibrium Model (MEM)
The zero-dimensional Marsh Equilibrium Model provides a beautiful example of how a salt marsh plant community  interacts with the physical environment to perpetuate that environment for the survival of the salt marsh (within limits).  Call it salt marsh Gaia if you will.  MEM III (rev. 9-5-11) is the successor to the Morris et al. model published in 2002.  New to MEM III is a more explicit treatment of belowground organic matter and the incorporation of the sediment cohort model SEMIDEC (Morris and Bowden 1986).  The online version allows users to perform sophisticated experiments and to simulate sedimentation and sediment organic matter profiles in any tidal marsh. See Marsh Equilibrium Model 3.4 description and Instructions for Modifying and Executing MEM III for more info.