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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