Four Chambers Studio: San Francisco Bay Model at the Exploratorium

<%@LANGUAGE="VBSCRIPT" CODEPAGE="65001"%> Four Chambers Studio: San Francisco Bay Model at the Exploratorium

The new interactive exhibit, Bay Model: A working prototype, models the complex dynamics of the San Francisco Estuary and reveals the hidden tidal fluctuations, currents, and river inflow. Visitors can launch virutal "floaties" into the bay and view the paths that the floaties take on a 6' x 6' three dimensional terrain model. A touchscreen provides launch options and a side panel displays additional data about the floaties, tides, and currents.

Once a floatie is launched the following data and visuals are displayed...

floatie location and trace of its path
night / day shadows and lighting on the terrain model
water surface levels and tide/current vectors
14-day tide cycle and current tide
clock showing accelerated progression of time
distance floatie is traveling on the bay / speed of floatie

Project Development & Support

The exhibit is being developed in conjunction with the Outdoor Exploratorium, a project promoting observation and experimentation with outdoor phenomena.

Concept Development: Peter Richards
Engineer: Dr. Oliver Fringer
Artists: Dan Collins and Gene Cooper
Technical Support: Don Vance, Vivien Pei Wen Chu
Fabrication: Russ Overbeck, Gizmo Art Productions, Kreysler & Associates
Data Sources: National Oceanic and Atmospheric Administration, National Geophysical Data Center, United States Geological Survey

This exhibit is based upon work supported by the National Science Foundation under grant ESI-0104478. Additional support comes from The Andy Warhol Foundation, the National Endowment of the Arts, and Grants for the Arts / San Francisco Hotel Tax Fund.

Photo and Video Clips of the Exhibit

The Science Behind the Floaties

The floatie locations are computed by tracking where they will move in response to the currents induced by the tides and inflow from the Sacramento and San Joaquin rivers in the northeast corner of this display. These currents are computed with software called SUNTANS, which solves the equations governing the flow of water in the Bay on a grid composed of 6,266 triangles. The currents in each of these triangles is indicated by the arrows that move back and forth with the tides, while the height of the water is indicated by the color surrounding each arrow. The SUNTANS software takes as its inputs the river inflow from the Sacramento and San Joaquin rivers and the height of the water surface in the Pacific Ocean. These inputs influence the currents and height of the water throughout the Bay.

Understanding how floaties move around in San Francisco Bay under the influence of the river inflow and the tides gives us clues as to how waterborne pollutants and plants and animals move around the Bay. For example, the motion of buoys is used by wastewater treatment engineers to determine the optimal location of treated sewage outfalls that most efficiently flush potentially harmful waste into the Ocean. Buoy motion might also be used by biologists to understand how certain species of phytoplankton and fish move around in the Bay, as well as Civil Engineers who need to understand how sediments are transported in response to the tidal currents.

SUNTANS was developed by Prof. Oliver Fringer in the Department of Civil and Environmental Engineering at Stanford University. Vivien Chua, a doctoral candidate working with Prof. Fringer, developed the particle tracking model and the implementation for San Francisco Bay. For more information please see http://suntans.stanford.edu

Tidal data in the Pacific Ocean was obtained from the National Oceanic and Atmospheric Adminstration (NOAA) tide gauge at the Golden Gate Bridge, and the topography data was obtained from the U.S. Geological Survey (USGS) and the National Geophysical Data Center (NGDC).