probing tools and/or science algorithms is a legitimate reason to choose one equally capable

model over another.

Experience of Staff and Available Contractors. This is a legitimate criterion for

choosing among several otherwise acceptable alternatives. The past experience might be with

the air quality model itself, or with a meteorological or emissions model which can be more

readily linked with one candidate air quality model than another.

Required vs. Available Time and Resources. This is a legitimate criterion provided the

first two criteria are met.

Consistency of a Proposed Model with Models Used in Adjacent Regions. This

criterion is applicable for regional model applications. If candidate models meet the other

criteria, this criterion should be considered in choosing a model for use in a regional or nested

regional modeling application.

Demonstration that an “Alternative Model” is Appropriate for the Specific

Application. If an air quality model meets the prerequisites identified in Section 13.2, a

State/Tribe may use the factors described in this section (Section 13.3) to show that it is

appropriate for use in a specific application. The selection of an “alternative model” needs to be

reviewed and approved by the appropriate U.S. EPA Regional Office.

Satisfactory Model Performance in the Specific Application. Prior to use of a

selected model’s results in an attainment demonstration, the model should be shown to perform

adequately for the specific application. The approach for evaluating model performance are

discussed in Section 18.

13.4 What Are Some Examples Of Air Quality Models Which May Be Considered?

Air quality models continue to evolve and have their own strengths and weaknesses



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


   Flag of Portugal 


 castellano: DISPER CUSTIC DESCAR RADIA    italiano:     


 français:    português:  






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