Three-dimensional rendition of salinity 

 in Chesapeake Bay. 



uated on a 32-node Kendall Square Research KSR-1 

 and an Intel iPSC/860 at the National Institutes of 

 Health. A variety of partial differential equation solvers 

 are also being implemented for performance evaluation 

 on both the MasPar and KSR machines. 



To foster communication among scientists currently per- 

 forming molecular modeling research on highly parallel 

 machines, EPA and the Office of Naval Research jointly 

 sponsored the "Molecular Modeling on Parallel 

 Computers" workshop session at the 1993 Sanibel 

 Symposium. 



Multimedia Modeling 



A multimedia project has been initiated by porting three 

 single-medium (or single-disciplinary) models to super- 

 computers - specifically a comprehensive regional air 

 quality model, a watershed-water quality model, and a 

 three-dimensional, bay hydrologic-water quality model. 

 These models are used to address the nitrogen eutroph- 

 ication of Chesapeake Bay - an environmental problem 

 involving two major pollutant pathways of major concern 

 to the Nation. 



The three models have been ported to a Cray Y-MP, 

 and the air quality model has been optimized there. 

 Current research focuses on linking these models 

 together when there is only minor interaction among the 

 different media, thereby maintaining the full disciplinary 

 complexity of known and tested individual models while 

 demonstrating the added benefit of multimedia modeling 

 for environmental decision making. 



Visualization 



As computer capability increases, interaction among the 

 different media and synergisms involving scores of pol- 

 lutants are being introduced into environmental models. 

 As a result, these models are becoming increasingly 

 complex. Visualization groups supported by EPA's 

 HPCC Program have developed high-quality videos of a 

 regional acidic deposition model and an air quality 

 model, demonstrating the power that visualization has to 

 open up the workings of these models to both scientists 

 and non-scientists. 



This effort was recently expanded as visualization 

 experts began working with water quality scientists to 

 display the output of increasingly complex sediment 



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