Assess the Far Field Effects of tidal Power Assess the Far Field Effects of tidal Power Extraction on the Bay of Fundy, Gulf of Extraction on the Bay of Fundy, Gulf of

Maine and Scotian ShelfMaine and Scotian Shelf

Researchers: Researchers: Jinyu Sheng, Keith Thompson Jinyu Sheng, Keith Thompson Dave Greenberg, Paul HillDave Greenberg, Paul HillDaisuke HasengawaDaisuke Hasengawa

Collaborators: Collaborators: Richard Karsten, Jim WarnerRichard Karsten, Jim Warner

(January 29, 2010)

• The Bay of Fundy and Gulf of Maine system has a natural resonant period very close to the main semi- diurnal lunar tide. This results in the world’s highest tides and strong tidal currents in the Bay of Fundy, particularly in Minas Channel and Minas Basin.

• Physical and ecological conditions in the “far field” could undergo significant changes given significant extraction of tidal power from this near-resonant system.

• The “far field” is defined as regions far from the turbine site.

Introduction

M2 Tides in the Gulf of Maine and the Bay of Fundy

(Sucsy, Pearce and Panchang, JPO, 1993)

Changes in M2 amplitudes if a barrier is placed in the upper Bay of Fundy

(Sucsy, Pearce and Panchang, JPO, 1993)

Barrier

Sub-tidal Circulation in the Gulf of Maine and Bay of Fundy

Main Objective: To quantify far field effects of tidal energy extraction in the Bay of Fundy on physical environments in the GOM-SS-BOF including the changes of:

• Tides and tidal circulation• Temperature and salinity distributions• Sediment distribution.

Research Approach: A state-of-the-art, four-level nested-grid ocean

circulation model based on Dalcoast.

Domains of 4-level nested-grid models to be developed

• Phase 1 focuses on the development of a nested- grid ocean modelling system using the Princeton Ocean Model. Most of the effort in this phase will be spent on embedding the higher resolution grids in DalCoast3 leading to the finest horizontal resolution of about 1 km in the Bay of Fundy.

• Phase 2 assesses the far-field effects driven by tidal power extraction in the upper Bay of Fundy based on model predictions with and without turbines in order to quantify their effect on the physical environment.

The research project takes two phases:

• The physical variables to be examined: sea level, horizontal current, temperature and salinity, bottom current and bottom stress (for sediment transport calculations).

• For each variable, the combined effect of tide and surge will be calculated for two cases: with and without the turbines. The calculations will be used to help assess the impact of tidal power extraction on the following far field conditions:

(a) tides, tidal currents, and horizontal and vertical distributions of water temperature and salinity;

(b) the change in the frequency (or equivalently return period) of extreme water levels (surge and tide combined) in the Bay of Fundy and Gulf of Maine system;

(c) large-scale sediment patterns in the Bay of Fundy, Gulf of Maine and Scotian Shelf.

Level 1Level 1

Level 2Level 2 Level 3Level 3 Level 4Level 4

A 4-level nested-grid ocean circulation model for the Bay

of Fundy to be developed based on Dalcoast

Dalcoast-2D (Storm Surge)

Dalcoast-3D (U, , T, S)

Gulf of Maine/Bay of Fundy Model

Bay of Fundy Model

Tides

L1:

L2:

L3:

L4:

NCOPS-BOF (4 level nested-grid model)

Model domain for barotropic mode

Model domain for baroclinic mode

DALCOASTDALCOAST was developed by originally Josko Bobanovic and Keith Thompson at Dalhousie University based on the Princeton Ocean Model (POM). It comprises two components:

• 2D barotropic component for the eastern Canadian shelf • 3D baroclinic component for the GSL and SS

Prototype Operational Shelf Prototype Operational Shelf Circulation forecast system: DalcoastCirculation forecast system: Dalcoast

•

Forecast and hindcast capacity

of predicting storm surge over the eastern Canada shelf

•

Forecast capacity

of predicting 3D circulation and temperature/salinity on the Scotian Shelf and Gulf of St. Lawrence

•

Hindcast capacity

of simulating 3D circulation and T/S fields on the Scotian Shelf.

•

Dalcoast has well be calibrated and validated

Main features of DALCOAST:

Sept Iles

Rimouski

Rivière-au-Renard

Lower Escuminac

Port aux Basques St. John’s

Argentia

Halifax

Charlottetown

North Sydney

Yarmouth

Saint John

Tide Gauge LocationsTide Gauge Locations

Storm Surge Forecast ExampleStorm Surge Forecast Example

17/11/2002 24/11/2002 01/12/2002

-40

0

40

cm

Rimouski, Late November 2002Rimouski, Late November 2002

eta-tidesurge model

M2 Tidal Elevations in Bay of Fundy

(Produced by sub-model L4 of NCOPS-BOF)

Comparison of observed and simulated M2 amplitudes and

phases in the Bay of Fundy

Simulated sea surface temperature (SST) and salinity (SSS)

(Produced by sub-model L4 of NCOPS-BOF)

The measureable and verifiable results of this project include:(a) a nested-grid ocean circulation modelling system

(b) maps and analyses showing the far field effects of tidal energy extraction on the physical environment including three-dimensional, time-varying ocean currents and hydrographic distributions (critical for a quantitative assessment of ecosystem impacts); frequency of extreme water levels; and sediment distributions in the Gulf of Maine and the Scotian Shelf.

Collaborations• We will work closely with the research team led by Richard Kartsten and David Greenberg focusing on the near-field, barotropic modelling of tides in Minas Channel and Minas Basin in order to parameterize the effect of turbines on our inner model.

• Our model results will be made available to the near-field hydrodynamic team in order to specify open boundary conditions for their circulation model in the inner BOF. Our model results will also be made available to other teams in more detailed study of sediment dynamics (e.g., Smith and Mulligan).

• Environmental consequences of extreme events on coastline integrity (Warner et al.) and ecosystem response to tidal energy extraction and ecosystem response.