Marine Models最新文献

LAGCARTW (Lagrange Cartesian suite for Windows) provides a simple method for simulating and understanding diffusion using computer animations of random walk particles. The model is useful for teaching and demonstration purposes, but may also be used in an investigative mode—the suite optionally produces output files of particle positions which can be used in subsequent analysis. Current velocities (defined as a series of tidal harmonics) are defined over the model domain, and particles can be discharged from a series of outfalls, reflected or absorbed by boundaries, and allowed to decay. The program also allows a variable diffusion coefficient in the vertical plane. The input file can be altered quite easily via a separate interactive program. A series of demonstration files, used to illustrate examples of diffusion problems, are provided.

CotSim is a size-structured metapopulation model of the crown-of-thorns (Acanthaster planci) on the central Great Barrier Reef (GBR). The populations of starfish and the coral cover on 269 individual reefs are modelled for up to 200 years. Starfish are represented as larvae, two age classes of juveniles and three size classes of adults. Coral can either be modelled as a single type or as two types each with a characteristic growth rate, equilibrium cover and susceptibility to starfish predation. Reefs are connected using simulated dispersal data for A. planci on the central GBR. These data were generated using a particle tracking program where simulated currents displaced particles representing dispersing larvae after an A. planci spawning episode. The dispersal data represented patterns expected from the 1976/77 to 1989/90 spawning season. The starfish growth model is a density-dependent matrix model. When coral cover is low, survival within classes is low and the transitions into larger classes is impeded. In contrast, at high coral cover the reverse patterns occur. Both the starfish and coral data are filtered through an interpretation model to generate observed patterns. The starfish interpretation model represents the important difficulty in detecting smaller adults. Results from the model using the default parameters correspond with published patterns of starfish/coral dynamics and the overall patterns of starfish outbreaks on the GBR.

The model is an interactive event-driven 32-bit Windows application requiring Windows 95 or Windows NT 3.51/4.0. Most parameters are able to be altered by the user with three tabbed dialogue boxes (for the simulation, starfish and coral parameters). Biologically justifiable default parameters are provided for all parameters. Parameters and initial starfish populations are stored in simple coded ASCII files. Simulations are controlled using ‘Run’, ‘Pause/Continue’ and ‘Stop’ operations. Maps of the GBR illustrate the spatial and temporal structure of the metapopulation dynamics including the patterns of dispersal. Once paused, populations on individual reefs can be examined using two types of plots (time series and single time bar charts). Overall patterns can be displayed using latitude versus time plots of observed reef state. Starfish populations and coral cover can be edited, which enables users of the model to become associated with some of the key issues regarding large-scale starfish control programs. Results from the model can be written to ASCII files for additional analysis. The speed of a simulation is able to be controlled and colours for important graphical elements can be altered. CotSim includes indexed online context-sensitive help and a graphical install routine. The program adheres to published guidelines for Windows applications.

A 1-dimensional (vertical) physical-biological coupled model is presented. The model is designed for investigations into the link between the vertical turbulent structure of a coastal or shelf sea water column, and the primary production. The physical model employs a turbulence closure scheme to provide the link between local vertical stability (driven by seasonal solar heating) and the vertical turbulent mixing (driven by tidal currents and surface wind stress). The biological component of the model is a simple cell quota, threshold limitation model, with either 1 or 2 taxa/species of phytoplankton growing in response to light and dissolved inorganic nitrogen. The user has control over all model physical and biological driving parameters. Graphical screen output, suitable for basic visualisation and teaching purposes, is generated as the model operates, and more detailed data are written to files for later analysis.

In order to demonstrate the model's use in simple hypothesis investigation, an example of the model operation is illustrated. This focuses on the effect that the springs-neaps tidal cycle has on the production within the summer sub-surface biomass maximum, illustrating the fortnightly input of new nitrogen into the thermocline and the subsequent new production.

Mooring Design and Dynamics is a set of Matlab® routines that can be used to assist in the design and configuration of single point oceanographic moorings, the evaluation of mooring tension and shape under the influence of wind and currents, and the simulation of mooring component positions when forced by time-dependent currents. The static model will predict the tension and tilt at each mooring component, including the anchor, for which the safe mass will be evaluated in terms of the vertical and horizontal tensions. Predictions can be saved to facilitate mooring motion correction. Time-dependent currents can be entered to predict the dynamic response of the mooring. The package includes a preliminary database of standard mooring components which can be selected from pull down menus. The database can be edited and expanded to include user specific components, frequently used fasteners/wires etc., or unique oceanographic instruments. Once designed and tested, a draft of the mooring components can be plotted and a list of components, including fasteners can be printed.