High-resolution Modeling for Consequence Assessment during the 2004 Summer Olympic Games

 

John Hannan¹, Patrick Hayes¹ and Martin Bell²

 

  ABSTRACT  

            The 2004 Summer Olympic Games in Athens, Greece represented a potential high-value target for disruption by terrorist individuals and organizations.   As part of security operations for the Olympics, an international team of consequence management (CM) analysts employed models that predicted the atmospheric transport and dispersion (AT&D) of chemical, biological, radiological, nuclear, and high-explosive (CBRNE) agents in the event of an actual release.  One such model is the Defense Threat Reduction Agency (DTRA) Hazard Prediction and Assessment Capability (HPAC) toolset which was employed for use by forward and Reachback personnel abroad and at DTRA in Alexandria, VA.   

One of the most critical factors in generating realistic AT&D predictions with HPAC and other dispersion models is accurate meteorological information.  In addition to an accurate deterministic forecast, a quantification of the uncertainty associated with the prediction is imperative if CM analysts are to make informed decisions in emergency response situations.  The estimation of meteorological uncertainty is challenging, particularly in regions of complex terrain and/or coastline, such as over the Greek peninsula.  The problem is complicated further during the warm season when thermal gradients induced by land/water interfaces and terrain variability are at a maximum.  To provide the most accurate wind fields and uncertainty estimates for use in HPAC during the Olympics, DTRA meteorologists developed a high-resolution, probabilistic modeling capability that incorporated twelve mesoscale simulations from three different modeling systems on a twice-daily operational cycle.  The simulations were generated by the Air Force Weather Agency’s (AFWA) 1.67 km horizontal resolution MM5, DTRA’s 2 km OMEGA model and a suite of 2 km RAMS members created with differing initial conditions perturbed from the base state (OMEGA and RAMS were run locally at a DTRA facility).  All of the model members were analyzed in real-time for accuracy of performance based on traditional metrics.  The “best” performing model and ensemble statistics were then supplied to DTRA forward and Reachback personnel for use in HPAC calculations. 

This paper details results of DTRA’s operational meteorological modeling support during the 2004 Summer Olympics in Athens, Greece.  We describe the complexity of the modeling system including the generation of realistic mesoscale ensemble members, model performance, use of statistical information in HPAC and sensitivity of plumes to meteorological specifications.  The results of this study will shape future efforts involving the operational application of high-resolution, probabilistic meteorological models to drive AT&D models.

             

¹Northrop Grumman Information Technology, Defense Enterprise Solutions

6940 South Kings Highway, Alexandria VA 22310 ²ATK Mission Research Corporation

3665 JFK Parkway, Bldg 1, Suite 206, Fort Collins, CO 80525