Mini Workshop:
Modeling Ecosystems Dynamics

The modeling ecosystems dynamics groups at SDSU is a partnership between the Computational Science Research Center (CSRC) at SDSU and the Center for Hydro-Optics & Remote sensing at SDSU to address the many complex problems in our coast and oceans. This session will present some of the work that has been going along these lines from data collection and modeling to prediction.

Eddy Paths in the Gulf of Mexico by 3D Numerical Models

Sorayda Tanahara

Carlos Torres

Michel Crepon

Instituto de Investigaciones Oceanologicas
Universidad Autonoma de Baja California
Ensenada Baja California, Mexico

Abstract: The momentum equations describing a three-dimensional stratified flow in the beta-plane in the Gulf of Mexico basin are solved numerically using two models. Westward anticyclonic propagation as well as eddy-topography interaction are studied. It is found that typical anticyclonic westward path is modified by the vertical eddy structure, eddy-eddy interaction and their interaction with the shape of the basin.

Hydrodynamics Simulation by Environmental Forcing in the Bay Paracas, Pisco-Perú

Jorge Quispe Sanchez

Isabel Ramirez Aguilar

Octavio Moron Antonio

Abstract: The aim of is study is the investigation to characterize the hydrodynamics of physical processes in the Bay Paracas (13°40' S,76°20' W) located in Pisco, Perú. The hydrodynamic three-dimensional model ELCOM (Estuary and Lake Computer Model) was developed by B.R. Hodges, Centre Water Research (CWR) of the University of Western Australia (UWA). In order to use ELCOM model in the Bay Paracas, field measurements were performed to obtain the bathymetry of the Bay, hydrographic data to establish initial conditions, and boundary data to incorporate to the model. The model it solved on a rectangular cartesian grid, based on the grid of Arakawa-C. The ELCOM model considers the Navier-Stokes equations with hydrostatic and Boussinesq approximation, the transport equation with one approximation by turbulent viscosity in the horizontal. The hydrodynamics simulation at the moment solves the equations of conservation for incompressible fluids using an semi-implicit scheme adapted of the family of TRIM models, based on the Euler-Lagrange quadratic method for the advection of the moment with a solution of conjugated gradient for the free surface The model was used in a cartesian rectangular grid dx = dy = 71m, forced with series time of tide, solar radiation, speed and wind direction, temperature of the air, relative humidity,with different initial and boundary conditions imposed to the model to analyze the ELCOM capacity and to reproduce environmental coastal conditions in the bay. Results of numerical simulation show the currents velocities and temperature, it include baroclínics and barotropic answers, rotational effects, tide forcing, wind, surface heating and salt transport. Tree-dimensional numerical simulations were use to investigate the behavior of currents dynamics and temperature by environmental forcing. Simulations are presented and compared with field data observed; its results contribute to a better understanding of currents velocities and temperature variability in the Bay Paracas.

Pressure Gradient Calculations in Curvilinear Models: The GCOM Case

Carlos Torres

Sorayda A. Tanahara

Abstract: Calculation of pressure gradients in three-dimensional stratified ocean models that use bottom-following sigma coordinates can lead to large errors near steep bathymetry. Ideally, a density stratified fluid, initially at rest and unforced, should continue to remain so indefinitely in time. However, this property may not be preserved, due to numerical errors associated with the numerical discretization of the horizontal pressure gradient terms if the vertical coordinate system differs from a z-coordinate system (
In order to examine pressure gradient errors in a General Curvilinear Ocean Model, the flow around a tall seamount is examined. The flow is initially at rest and the density is stratified in the vertical according to a known relation. Results are better than those reported in Shchepetkin and McWilliams (2003) for the same problem and metrics.

Center for Integrative Coastal Observations, Research
and Education (CICORE): A Coastal Observing Program

Charles Trees

Center for Hydro-Optics and Remote Sensing
San Diego State University
San Diego, California, USA

1Trees, C., 2P. Bissett, 3K. Cole, 4M. Craig, 5D. Dugdale, 5T. Garfield, 3K. Kamer, 2D. Kohler, 6R. Kvitek, 7M. Moline, 1J. Mueller, 8R. Piper, 9F. Shaughnessy and 10R. Zimmerman

1Center for Hydro-Optics and Remote Sensing, San Diego State University, San Diego, CA USA
2Florida Environmental Research Institute, Tampa, FL USA
3Moss Landing Marine Laboratories, Moss Landing, CA USA
4California State University East Bay, Hayward, CA USA
5Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon CA USA
6Science and Environmental Policy, California State University Monterey Bay, Monterey, CA USA
7Biological Sciences Department, California Polytechnic State University, San Luis Obispo, CA USA
8Ocean Studies Institute, California State University Long Beach, Terminal Island, CA USA
9Department of biological
Sciences, Humboldt State University, Arcata, CA USA
10Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, VA USA

Abstract: The California State University (CSU) Center for Integrative Coastal Observations, Research and Education (CICORE) is an applied coastal research center distributed throughout California. CICORE was established in 2002 with funding from the NOAA Coastal Observation Technology System (COTS) in an effort to create a coastal monitoring and research observatory network for the entire 1200 miles of the California coast. It utilizes the unique distribution of the CSU campuses to create a coastal ocean observatory along the entire California coastline that focuses on the region from 100 meter deep up to and on to the shore, including estuaries, wetlands, and other critical coastal habitats. CICORE uses three core technologies (high resolution acoustic bathymetry and habitat mapping, high resolution airborne hyperspectral imagery and in-situ water quality and meteorological monitoring) to address economically and environmentally important challenges such as coastal erosion, watershed impacts, chemical contamination of food webs, depletion of marine commercial resources, toxic plankton blooms, marine pathogens and the rapid invasion of coastal waters by non-indigenous species. The objectives of CICORE are (1) to establish research & monitoring infrastructure of critical coastal habitats in California. (2) to develop models for predicting change in coastal environments, (3) to enhance management capability of regulatory & resource management agencies, and (4) to enhance public awareness of the importance of coastal management. The CICORE program will be discussed in the context of the Global Ocean Observing System (GOOS) for observations, modeling and analysis of marine and ocean variables to support operational ocean services worldwide.