PIE-FVCOM 3D Hydrodynamic Model

As part of the PIE LTER program, we are developing FVCOM for the Plum Island Estuaries that is coupled to the coastal zone and the Merrimack River. FVCOM is a 3D, primitive-equation, finite-volume hydrodynamic model developed by Changsheng Chen at UMass Dartmouth (see FVCOM). Liuzhi Zhao (UMass Dartmouth), Joe Vallino (MBL) and Changsheng Chen are the primary developers of PIE-FVCOM. This page contains some preliminary results.

Here 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 NGDC bathymetry surveys. Click image below to download AVI file. This older modeling domain does not include the connection to the Merrimack River. File is 12.6 MB.

The following simulations explore the connection between Plum Island Sound and the Merrimac River that are connected via the Plum Island River and the coastal zone.

The simulation (on right) shows salinity and tidal elevation along a 2D transect (depth vs length) through the Parker River and Plum Island Sound. These simulations were compared to CTD transects, which were used to assist in model calibration. Fresh water forcing enters via the Parker River (at left in simulation). Due to high tidal energies and shallowness of the estuary, the estuary does not exhibit much vertical stratification as evident in the simulations. Fresh water inputs from other rivers are also included in the whole simulation. File is 53 MB.

Salinity transection along the PI Sound and Parker River.

2D cross section at the Southern mouth of PI Sound

This simulation (on left) shows velocity and salinity in a 2D cross section taken at the Southern mouth of Plum Island Sound. The perspective is from the Gulf of Maine looking into the Sound. Velocities along this and several other cross sectional transects along the Parker River, Ipswich River, Rowley River, Plum Island River, Eagle River and Sound were compared to ADCP surveys to verify model prediction skill. File is 60 MB.

This simulation (on right) shows particles released at various locations within PIE and the Merrimac River at maximum flood velocity. Note the particles leaving the Merrimac River can be entrained into the Sound, and particles in the Sound can be exported to the Merrimac via the Plum Island River. Analysis of residual currents shows that a large clockwise circulation develops from PI Sound heading north into the Merrimack River via PI River, then onto the shelf from the Merrimack River mouth where it then travels southerly along the shelf before being entrained back into PI Sound via the southern mouth. File is 45.8 MB.

Tidal flooding & drying and surface salinity

The simulation (on left) shows how salinity changes over several tidal cycles across the entire estuarine-river-shelf complex. Note that during flood tide a large bolus of fresh water in the Merrimack River gets injected into the northern part of Pl River.

The images below show surface salinity during ebb and flood tides (left) and residual current tidal phase and velocities (right). Click images for larger versions.