View source for National Atmospheric Release Advisory Center

{{YouTube video|description=NARAC Overview|url=https://www.youtube.com/watch?v=aKwLwY6CNf8}}

The '''National Atmospheric Release Advisory Center''' (NARAC) is located at the University of California's [[Lawrence Livermore National Laboratory]]. It is a national support and resource center for planning, real-time assessment, emergency response, and detailed studies of incidents involving a wide variety of hazards, including nuclear, radiological, chemical, biological, and natural emissions.

NARAC provides tools and services to federal, state and local governments, that map the probable spread of hazardous material accidentally or intentionally released into the atmosphere.

NARAC provides [[atmospheric dispersion modeling|atmospheric plume predictions]] in time for an emergency manager to decide if protective action is necessary to protect the health and safety of people in affected areas.

{{Official URL|text=narac.llnl.gov|url=https://narac.llnl.gov}}

== The NARAC facility includes ==

* Scientific and technical staff who provide support and training for NARAC tools, as well as quality assurance and detailed analysis of atmospheric releases.
* 24 hour x 7 day on-duty or on-call staff.
* Training facility.
* An Operations Center with uninterruptible power, backup power generators, and robust computer systems.
* Links to over 100 emergency operations centers on the U.S.
* A team of research and operational staff with expertise in atmospheric research, operational meteorology, numerical modeling, computer science, software engineering, geographical information systems, computer graphics, hazardous material (radiological, chemical, biological) properties and effects.

==The Emergency Response System: Real time dispersion modeling==

The NARAC emergency response central modeling system consists of an integrated suite of [[meteorology|meteorological]] and [[atmospheric dispersion modeling|atmospheric dispersion models]].<ref>{{cite book|author=Turner, D.B.|title=Workbook of atmospheric dispersion estimates: an introduction to dispersion modeling|edition=2nd|publisher=CRC Press|year=1994|isbn=1-56670-023-X|url-access=registration|url=https://archive.org/details/workbookofatmosp0000turn}} [http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=L1023&parent_id=&pc= www.crcpress.com] {{webarchive|url=https://web.archive.org/web/20071105075907/http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=L1023&parent_id=&pc= |date=2007-11-05 }}</ref><ref>{{cite book|author=Beychok, M.R.|title=[[Fundamentals Of Stack Gas Dispersion]]|edition=4th|publisher=author-published|year=2005|isbn=0-9644588-0-2}} [http://www.air-dispersion.com www.air-dispersion.com]</ref> The meteorological [[data assimilation]] model, ADAPT, constructs fields of such variables as the mean [[wind]]s, [[pressure]], [[Precipitation (meteorology)|precipitation]], [[temperature]], and [[turbulence]].<ref>Sugiyama, G., and S. T. Chan  (1998), ''A New Meteorological Data Assimilation Model for Real-Time Emergency Response'', 10th Joint Conference on the Applications of Air Pollution Meteorology, Phoenix, Arizona, January, 1998.</ref>  Non-divergent wind fields are produced by a procedure based on the variational principle and a [[finite element method|finite-element discretization]]. The dispersion model, LODI, solves the 3-D advection-diffusion equation using a [[Air pollution dispersion terminology|Lagrangian]] [[stochastic]], [[Monte Carlo method]].<ref>Ermak, D.L., and J.S. Nasstrom (2000), ''A Lagrangian Stochastic Diffusion Method for Inhomogeneous Turbulence'', Atmospheric Environment, 34, 7, 1059-1068.</ref>  LODI includes methods for simulating the processes of mean wind advection, turbulent diffusion, radioactive decay and production, bio-agent degradation, first-order chemical reactions, [[Air pollution dispersion terminology|wet deposition]], gravitational settling, [[Air pollution dispersion terminology|dry deposition]], and [[Air pollution dispersion terminology|buoyant]]/momentum plume rise.

The models are coupled to NARAC databases providing topography, geographical data, chemical-biological-nuclear agent properties and health risk levels, real-time meteorological observational data, and global and mesoscale forecast model predictions. The NARAC modeling system also includes an in-house version of the Naval Research Laboratory's mesoscale weather forecast model COAMPS.<ref>Hodur, R. M. (1997), ''The Naval Research Laboratory's Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS)'', Mon. Wea. Rev., 125, 1414-1430.</ref>

== See also==
* [[Materials MASINT]]
* [[Accidental release source terms]]
* [[Air Resources Laboratory]]
* [[Air Quality Modeling Group]]
* [[Atmospheric dispersion modeling]]
* [[Department of Public Safety]]
* [[National Center for Atmospheric Research]]
* [[University Corporation for Atmospheric Research]]

==References==

<references/>

==External links and sources==
{{Commons|Lawrence Livermore National Laboratory}}
* [http://narac.llnl.gov National Atmospheric Release Advisory Center] (official website)
* [http://www.llnl.gov Lawrence Livermore National Laboratory] (official website)
{{Lawrence Livermore National Laboratory|state=autocollapse}}

[[Category:Atmospheric dispersion modeling]]
[[Category:Lawrence Livermore National Laboratory]]