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Regional Specialized Meteorological Center for Transport and Dispersion Model Products

Overview

As a result of the poor communications between countries following the Chernobyl accident in the Spring of 1986, the World Meteorological Organization (WMO) was asked by the International Atomic Energy Agency (IAEA) and other international organizations to arrange for early warning messages about nuclear accidents to be transmitted over the Global Tele-communications System (GTS). In addition some WMO member countries lacking extensive forecasting capability requested that specialized pollutant transport and dispersion forecasts be provided during these emergencies.

In 1989, Regional Specialized Meteorological Centers at Toulouse (Meteo-France), Bracknell and Montreal were set up under interim arrangements between the WMO and the IAEA. Under these arrangements Meteo-France was to provide global coverage (with Bracknell as the backup center) until each WMO region had at least two RSMCs for transport model products.

The need for rationalization of transport and dispersion forecasts became even more apparent during the oil fire emergency after the Gulf War, when many organizations provided ground personnel with predictions of the smoke plume behavior. These predictions were often misleading; there was no existing and well-recognized system to sort out the predictions from less experienced sources.

In November 1992, a demonstration of NOAA's RSMC capabilities was made to the WMO's Commission for Basic Systems (CBS) during their Tenth Session. Following this demonstration, the NOAA RSMC was accepted by WMO and subsequently became effective 1 July 1993. The addition of RSMC Washington resulted in two RSMCs per WMO region (RA) - Washington and Montreal (RA IV) and Toulouse and Bracknell (RA VI) - and indicated the need to revise the interim arrangements. Under the new global arrangements, Region IV will be responsible for parts of Central and South America Region III, while Toulouse and Bracknell would cover the remaining Regions I and II (Africa and Asia). These new global arrangements were finalized at the WMO/CBS session in August 1994.

Since then, other RSMCs have been accepted by WMO including, Melbourne, Australia (RA V); Beijing, China (RA II); Obninsk, Russian Federation (RA II); and Tokyo, Japan (RA II). RSMC Melbourne has been initiated using some of the Washington (i.e. ARL) procedures and dispersion models. The RSMCs in Washington and Montreal will provide backup to Melbourne until another RSMC is specified for RA V. RSMC Toulouse and Bracknell are now responsible for RA I and VI.

Structure.

The RSMC Washington is a joint venture between the NOAA NWS National Centers for Environmental Prediction (NCEP) and the Air Resources Laboratory, merging the forecast skills and operational capabilities at NCEP with the pollutant dispersion modeling and analysis capabilities of ARL. In essence, NCEP provides the 24 hour per day initial contact point for assistance requests. In the event of an accident, the NCEP operational staff run the initial response model on their powerful supercomputer and distribute the products via facsimile. Subsequently, ARL emergency responders would be notified of the response and begin to work with NCEP and Montreal to develop a joint statement of model differences. Model outputs would be distributed automatically to predesignated country representatives.

After the initial response by NCEP, ARL will work jointly with NCEP and possibly update the dispersion model products to more accurately reflect the current conditions of the accident.

By agreement with the Canadian Meteorological Center (CMC), RSMCs Washington and Montreal will respond jointly to emergencies in their region of concern, each sending products to countries requesting assistance, as well as consulting with each other regarding model output differences, product interpretation, end uncertainty. Regular monthly tests are conducted with the CMC.

Recently, a joint project was initiated between ARL and NCEP to develop a more operational coupled meteorological-dispersion model. Modifications have been made to NCEP's Regional Spectral Model (RSM) to permit its application over any region of the globe. RSM model outputs are linked directly with ARL dispersion models.

Example and Future Activities

The standard model products to be distributed include forecasts of trajectories, exposures, and deposition using the HYSPLIT transport and dispersion model. There is a continuing program intended to identify occasions in which differences in RSMC predictions arise, and to find the causes for these differences. Dispersion model differences are partly due to differences in meteorological model's spatial resolution as well as the effects of the Lagrangian or Eulerian methods used to compute the pollutant dispersion. Prediction differences will have to be addressed by emergency planners when confronted by multiple model output products. Regional RSMCs (such as Washington and Montreal) will issue joint statements on differences between their products.

Interactive Training Program

Software has been developed for MS-DOS PCs to provide a basic level of training for operations and research staff that might be involved with atmospheric emergency response functions of the RSMC. The program is customized for the products of Washington's RSMC but the types of products and display requirements are generic to all the RSMCs. The program is divided into three parts. The first part reviews the background and operational requirements of the RSMC. The second part gives a detailed description and interpretation guidelines for the products. The third part is interactive, using a condensed version of the operational dispersion model, permits the user to test various accident and meteorological scenarios. The software is provided as a self-extracting .EXE file and should be placed in its own directory. The program is available in English, French, or Spanish.

Web Resources

WMO Emergency Response Information

List of Publications

Draxler, R.R., G.D. Rolph, J.T. McQueen, J.L. Heffter and B.J.B. Stunder, 1993: NOAA Washington GDPS Regional Specialized Meteorological Center on the Provision of Transport Model Products for Environmental Emergency Response.

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