Background
Background

Connie3 uses archived currents from oceanographic models and particle tracking techniques to estimate connectivity statistics from user-specified source regions (or to user-specified sink regions).

The user can select from 3 modes of operation:

  1. Substance/organism where behaviours have been predefined on the basis of information from the scientific literature.
  2. Passive dispersal where the user specifies the depth and the dispersal time.
  3. Complex behaviour where the user can specify a wide range of physical and biological behaviours including vertical migration; horizontal propulsion or swimming (user-specified random or constant velocity); floatation or surface slick formation (user-specified windage); and multiple phases of behavior.
Oceanographic Models

The Australasia/Southeast Asia model was developed using OFAM (Ocean Forecasting Australia Model) which was developed using the Modular Ocean Model (MOM4) code as part of the BLUElink Project. It is a data-assimilating oceanographic model that is used for operational ocean forecasting by the Australian Bureau of Meteorology and for reanalysis by CSIRO (BRAN). It is a global model that is eddy-resolving (0.1 degrees in latitude and longitude) over the region 90E–180E, 60S–10N. The Bluelink Reanalysis archive used by Connie3 contains daily outputs over the period 1993–2007.


The Coral Sea model was developed using the SHOC hydrodynamic model developed as part of the CSIRO Environmental Modelling Suite (EMS). It has a resolution of 4 km and covers the Great Barrier Reef section of the continental shelf, slope and deep ocean from Moreton Bay to the mainland of Papua New Guinea. Offshore boundary conditions are provided by BRAN.


The Great Barrier Reef model (GBR1) was also developed using the SHOC hydrodynamic model. It has a resolution of approximately 1 km and covers the Great Barrier Reef from Moreton Bay to the mainland of Papua New Guinea. Offshore boundary conditions are provided by the Coral Sea model (GBR4).


The Victorian Coast model was also developed using SHOC. It has a resolution of approximately 600 m and covers Port Phillip Bay, Western Port Bay, northern Bass Strait and all waters to at least 100 km off the Victorian coast. This model runs in near-real time and provides short-term forecasts.


The Southeast Tasmania model was also developed using SHOC. It has a resolution of approximately 200 m and covers the Huon Estuary, D’Entrecasteaux Channel, Derwent Estuary, Frederick Henry Bay, Norfolk Bay, and Storm Bay.


The Eastern Tasmania model is another model developed using SHOC. It has a resolution of approximately 2km and covers the continental shelf and slope off eastern Tasmania (ETAS). Further information about this model can be found at the following - Modelling the shelf circulation off eastern Tasmania


The Mediterranean Sea Reanalysis (MEDREA) was developed using the OPA 8.1 code for the Mediterranean Sea and adjacent North Atlantic Ocean region, which forms part of the Mediterranean ocean Forecasting System (MFS). The data assimilating model has 1/16th degree horizontal resolution and includes realistic evaporation and river discharges. The current version of the reanalysis covers the period 1985 to 2007. Further information about this model can be found at the following - Quality Assessment of a 1985–2007 Mediterranean Sea Reanalysis

Particle Tracking Techniques

Particles are seeded within the user-specified source (or sink) region at a constant rate of 100 particles per grid cell per day over the user-specified release period. They are subsequently tracked individually using a 4th-order Runge-Kutta ODE solver that linearly interpolates in time and horizontal space to find the horizontal velocity at the required depth and time. An additional horizontal velocity component (constant or random) can be added to represent unresolved fluctuations or biological behaviour. Vertical migration can also be represented as instantaneous jumps between vertical levels. Where the deeper vertical level is beneath the seafloor, particles remain stationary until moving back to the shallower level..