More limited research has been conducted related to PM2.5 modeling. Most model

applications for the annual PM2.5 NAAQS have modeled a full year (CAIR, RPOs, etc). This is a

logical goal since every day of the year is included in the calculation of the annual NAAQS.

Several tests have also been made using less than a full year of meteorological data. One study

(Environ, 2004) found that modeling 14 days from each quarter provided results with a

reasonable amount of uncertainty compared to modeling the full year. The following sections

contain further recommendations for choosing appropriate time periods to model for attainment

demonstrations and glidepath assessments.

At a minimum, four criteria should be used to select time periods which are appropriate

to model:

1) Simulate a variety of meteorological conditions:

a) 8-Hour Ozone- Choose time periods which reflect a variety of meteorological

conditions which frequently correspond with observed 8-hour daily maxima > 84

ppb at multiple monitoring sites.

b) 24-Hour PM2.5- Choose time periods which reflect a variety of meteorological

conditions which frequently correspond with observed 24-hour averages > 65

ug/m3 at violating monitoring sites.

c) Annual PM2.5- Choose time periods from each quarter which reflect the variety

of meteorological conditions which represent average concentrations for that

quarter and year

d) Regional Haze- .Choose time periods which reflect the variety of

meteorological conditions which represent visibility impairment on the 20% best

and 20% worst days in the Class I areas being modeled.

 

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 

 english:

 castellano: DISPER CUSTIC DESCAR RADIA    italiano:     

 

 français:    português:  

 

deutsch:

 

 

 

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