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January-February 2012

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NARAC: There for You When You Need To Know Which Way the Wind Blows

Caption: Sunset in Hawaii influenced by volcanic eruption of Mt. Pinatubo in 1991.

Bob Dylan sang “You don't need a weatherman/To know which way the wind blows” in Subterranean Homesick Blues, but that's certainly not true when there are airborne toxic substances present. And specifically, you want the meteorologists, modelers, and other experts at the National Atmospheric Release Advisory Center (NARAC). In March of 2011, soon after the Fukushima Dai-ichi Nuclear Power Plant accident occurred in Japan, NARAC hit the ground running. During the days and weeks following the crisis, they issued dozens of forecasts and analyses, including daily weather forecasts of atmospheric transport predictions in support of measurements, surveys, estimates of possible radiation doses in Japan, and estimates of plume arrival times and dose estimates for locations in the United States.

In a nondescript building on the sprawling Lawrence Livermore National Laboratory (LLNL) campus, about 40 miles east of San Francisco, California, NARAC is tasked as the U.S. government's primary forecaster of the direction the bad stuff—from burning barrels or tires to biohazards to nuclear radiation—will spread, and its concentration. The scope of the NARAC mission has grown almost exponentially since its inception in 1973, when the Department of Energy (DOE) asked LLNL about the feasibility of a developing a computer-based system to estimate radiation levels following a U.S. nuclear emergency. The resulting collaboration of scientists and computing power allowed LLNL scientists to calculate probable scenarios of the radiological impact from the re-entry of a nuclear-powered Soviet Cosmos satellite in 1978 and the estimated trajectories from Chinese nuclear weapons testing.

On March 28, 1979, a stuck valve at the Three Mile Island nuclear reactor resulted in radioactive steam being vented into the atmosphere over Central Pennsylvania, and the LLNL scientists responded. Using a combination of dispersion models, meteorological models, and the latest in computing technology, they created a prototype emergency response system, and the Atmospheric Release Advisory Capability (ARAC) Operational Center became operational on April 1, 1979. The first forecasts for the Three Mile Island incident were run on the mainframe computers at LLNL, and the printout of the potential plume was hand-annotated with radioactive dosages and faxed—yes, faxed—to the incident managers in Pennsylvania.

The next decade would see the rapid development of ARAC, as greater computing power allowed for more sophisticated atmos-pheric modeling in shorter and shorter amounts of time. During the 1980s, ARAC forecasts were provided for several more radiological incidents and space-related accidents. These included the explosion of a nuclear warhead tipped Titan II missile in Arkansas in 1980, and the re-entry of another Cosmos satellite in 1983.

And then there was the partial meltdown and explosion at the Chernobyl nuclear power plant in the Ukraine in 1986 that released of millions of curies of radioactive iodine and cesium into the atmosphere. For 18 days, the round-the-clock operations of ARAC modeled the trajectories and estimated the radiological dosages for downwind areas of Europe, Western Asia, and around the globe.

The scope of ARAC's mission and activities continued to grow through the 1990s, as did its monitoring, computing, and forecasting power. The year 1991 alone provided several massive global challenges, from the expansive Kuwait oil field fires following the first Gulf War to the volcanic eruption of Mount Pinatubo in the Philippines. For the former, ARAC provided twice-a-day smoke and air quality forecasts to 17 different agencies and countries for a six-month period. During this same period, the explosive eruptions of Mount Pinatubo injected huge amounts of ash and pollutants high into the stratosphere, and it fell to ARAC to project safe flight paths for aircraft around the ash as well as support safe evacuation paths for as many as 20,000 United States military and civilians in the Philippines.

Caption: Fukushima I nuclear power plant before the 2011 explosion.

Caption: Fukushima I nuclear power plant before the 2011 explosion.

Caption: The June 12, 1991 eruption column from Mount Pinatubo taken from Clark Air Base.

Back in the United States, the personnel at ARAC also responded with forecasts following several large-scale railcar accidents involving hazardous material released into the environment. They also developed scenarios for possible accidents involving the launch of satellites, such as Cassini in 1997, that have nuclear power sources. During these launches, the Center is on alert, and ARAC staff members are on hand in Florida should something go wrong. This support of the United States space program is ongoing, with NARAC personnel frequently being deployed to Florida.

The year 1996 brought the dedication of a new NARAC facility at LLNL. This facility was specifically designed for the ARAC mission. It houses the state-of-the-art operations center, computer room, back-up power, training facilities, and offices for the staff of atmospheric scientists, modelers, programmers, and other specialists. It also allows for a place of synergy among the 40 ARAC experts and the hundreds of other scientists on the Lawrence Livermore campus. This is particularly important when a release involves a nontypical, “exotic” substance; assistance from another world class expert is often literally right across the street.

The latter half of the 1990s also saw the development of a new generation of both atmospheric and dispersion models by NARAC scientists. These incorporated the latest high-resolution terrain and meteorological data, new data assimilation techniques, and integration with the U.S. Navy COAMPs weather prediction model. This same era also brought about the development of full-physics computational fluid dynamics (CFD) models that simulated the flow and dispersion on scales as small as the size of individual buildings. This modeling has been used for the development of emergency response plans for facilities, cities, and special events.

Many of these advances came into play in mid-1997, when radiological stations in Europe detected small amounts of cesium in the atmosphere from an unknown source. By using these measurements, NARAC was able to reverse-engineer the event and reconstruct the trajectories from a potential source region. These projections were verified by Spanish authorities when they determined that medical radiotherapy materials had been accidently smelted at a scrap steel mill in Algeciras, near Gibraltar.

The growth of the Internet and the development of Java- and Web-based tools have allowed NARAC to roll out some of its modeling capabilities directly to the user community. These interactive tools allow users to directly access predictions that were integrated with geographic information systems and population data for improved responses to emergencies on a local level.

One of NARAC's most widely used tools is Hotspot—a program that provides a first-order approximation of the radiation effects associated with the release of radioactive materials into the atmosphere. The program gives emergency responders and planners a portable software tool for evaluating radioactive material incidents and their potential impacts. It is also used as a planning tool for facilities that handle radioactive materials.

These advances in technology and dissemination continued into the new century, with the integration of advanced modeling systems that were rolled out in five cities (Albuquerque, New Mexico; Cincinnati, Ohio; Fort Worth, Texas; New York, New York; and Seattle, Washington). The resulting Local Integration of NARAC and Cities (LINC) system was a prototype for the development of training, technology, and interagency support for emergency personnel and first responders.

The third-generation NARAC computer system went live in 2000 and is still the backbone of NARAC operations today. Each day, NARAC receives in excess of 1 million real-time weather observations and forecast data from the National Weather Service, the Air Force, and the Navy, as well as from international meteorological centers. This Unix-based computing center gave NARAC an expanded capability to integrate the latest in high-speed computing with the high-resolution weather forecast models and meteorological data networks.

The Post-9/11 World

The new century also brought to the forefront a new genre of atmospheric release problems: those associated with domestic terrorism. While NARAC did not model the resulting plumes following the attack on the World Trade Center in 2001, it did develop modeling for a wide range of post-9/11 scenarios of terrorist activities. These ranged the gamut from radioactive and biohazard releases to weapons of mass destruction (WMDs).

This era also saw NARAC become an integral part of the Department of Homeland Security's Interagency Modeling and Atmospheric Assessment Center (IMAAC) in 2004. IMAAC/NARAC's role is to be “the single point for the coordination and dissemination of federal dispersion modeling and hazard prediction products that represent the federal position.” Under this mandate, a Web site site was created that allows users to run and share plume-modeling simulations in near real-time.

Caption: NARAC is located at the University of California's Lawrence Livermore National Laboratory.

Caption: NARAC is located at the University of California's Lawrence Livermore National Laboratory.

In 2004, a chemical warehouse fire broke out at the Queen City Barrel facility in Cincinnati, Ohio, and involved dozens of different hazardous materials. NARAC assisted the City of Cincinnati's emergency response efforts by providing projections of both the smoke plume and an initial fire plume health effect estimate. After the bulk of the fire was knocked down, a post-analysis of the fire plume was conducted along with a health estimate associated with the remaining smoldering embers. The participation of NARAC provided the City of Cincinnati with the sophisticated tools it needed to issue timely evacuation and “shelter in place” orders and other critical emergency response decisions.

Another function of NARAC is to assist government agencies in modeling potential atmospheric releases during large public events. NARAC worked in conjunction with and supported activities such as the 2002 Winter Olympic Games in Salt Lake City, Utah; the 2004 Democratic Convention in Boston, Massachusetts; and the 2009 Presidential Inauguration in Washington, D.C. Overall, NARAC has thousands of users from a galaxy of 300 federal, state, and local emergency response organizations. The NARAC center generates an average of 10,000 plume forecasts per year, participates in approximately 100 major exercises, and responds to 25 real-world incidents.

Caption: Brenda Probanz and Ron Basektt of NARAC, Lawrence Livermore National Laboratory, are reviewing the NARAC response to the Queen City Fire.

Caption: Brenda Probanz and Ron Basektt of NARAC, Lawrence Livermore National Laboratory, are reviewing the NARAC response to the Queen City Fire.

At the same time, NARAC continues to remain on the cutting edge in research and development of modeling tools and techniques, as well as ongoing improvements of computer hardware and software. When a real-world hazardous release occurs, often the largest unknown is the “source term,” or the amount of material released. NARAC is constantly developing rigorous statistical methodologies to better model these initial amounts for event reconstruction. These methods have been tested successfully using tracer experiments, from local to continental scales, and are continuously being improved. Additionally, in conjunction with the Argonne and Berkeley National Laboratories, NARAC has developed a building “leakiness” database for calculating indoor dosages from an outdoor plume, along with a prototype coupled model to calculate the outdoor impacts from a hazardous release in a subway.

In conjunction with the National Center for Atmospheric Research (NCAR), NARAC has integrated the Weather Research and Forecasting (WRF) into its suite of emergency response models. It has also developed advanced turbulence and boundary methodologies that have been implemented in support of the WRF.

Caption: Burning oil field during Operation Desert Storm, Kuwait.

Caption: Burning oil field during Operation Desert Storm, Kuwait.

Caption: Chernobyl nuclear station.

Caption: Chernobyl nuclear station.

In the past decade, NARAC has supported many different types of events where toxic and/or harmful substances were spewed into the atmosphere. It has tracked and forecasted the dispersion of the plumes from numerous chemical fires, the most recent being those resulting from Hurricane Katrina, as well as the Deepwater Horizon blowout, explosion, and fire in the Gulf of Mexico. NARAC also forecast the VOG (or, volcanic smog) plume associated with the particularly severe eruptions of the Kilauea Volcano in Hawaii in 2008. The Environmental Protection Agency (EPA), National Park Service, and other public agencies used the high-resolution NARAC forecasts to keep the public safe from the 2,000 to 4,000 tons of sulfur dioxide being vented out of Kilauea every day.

Each year, NARAC receives approximately 7,000 operational requests from nearly 300 government agencies and 2,000 online users. The vast majority of emergency response incidents are handled through either NARAC iClient or the NARAC Web site, which are accessed via dial-up, satellite, Ethernet, and wireless networks. Major atmospheric releases are handled by the NARAC Operations Center, which can be activated as a 24/7 operation. Whatever the scope of the incident, be it a truck burning along a freeway with possible hazardous materials, the launch or re-entry of a satellite, a terrorist threat, or the potential meltdown of a nuclear reactor halfway around the world, users of NARAC have come to know that they are getting the best in applied, cutting edge science delivered by a cadre of world-class scientists.

Jan Null is a Certified Consulting Meteorologist and a founder of Golden Gate Weather Services. She is also a Lecturer/Researcher at San Francisco State University and former National Weather Service Lead Forecaster.

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