States/Tribes should use a non-proprietary model, which is a model whose source code is
available for free (or for a “reasonable” cost). Furthermore, the user must be able to revise the
code93 to perform diagnostic analyses and/or to improve the model’s ability to describe
observations in a credible manner. Several additional prerequisites should be met for a model to
be used to support an attainment demonstration or uniform rate of progress assessment.
92Appendix W recommends specific dispersion models for primary pollutants, but does
not recommend specific photochemical models. Recommended dispersion models should be
used for primary PM2.5 analyses if dispersion models are used for a “local area analysis”(see
93Air quality models are generally identified by a version number. The version of the
model that is used in SIP applications should be identified. Code revisions to standard versions
of models should be noted and documented.
(1) It should have received and been revised in response to a scientific peer review.
(2) It should be appropriate for the specific application on a theoretical basis.
(3) It should be used with a data base which is adequate to support its application.
(4) It should be shown to have performed well in past ozone or PM modeling applications.
(If the application is the first for a particular model, then the State should note why it
believes the new model is expected to perform sufficiently.)
(5) It should be applied consistently with a protocol on methods and procedures.
An air quality model may be considered to have undergone “scientific peer review” if
each of the major components of the modeling system (i.e., air chemistry/deposition,
meteorological and emissions models) has been described and tested, and the results have been
documented and reviewed by one or more disinterested third parties. We believe that it should
be the responsibility of the model developer or group which is applying an air quality model on
behalf of a State/Tribe to document that a “scientific peer review” has occurred. States/Tribes
should then reference this documentation to gain acceptance of an air quality model for use in a
modeled attainment demonstration.
n751 - n752 - n753 - n754 - n755 - n756 - n757 - n758 - n759 - n760 - n761 - n762 - n763 - n764 - n765 - n766 - n767 - n768 - n769 - n770 - n771 - n772 - n773 - n774 - n775 - n776 - n777 - n778 - n779 - n780 - n781 - n782 - n783 - n784 - n785 - n786 - n787 - n788 - n789 - n790 - n791 - n792 - n793 - n794 - n795 - n796 - n797 - n798 - n799 - n800
castellano: DISPER CUSTIC DESCAR RADIA italiano:
deutsch: DIS CUS DES RAD
castellano: DIS CUS DES RAD english: DIS CUS DES RAD
português: DIS CUS DES RAD italiano: DIS CUS DES RAD
français: DIS CUS DES RAD