is below detection limits, missing or invalid. The algorithm also uses three new water growth

adjustment terms. They are for use with the small size distribution and the large size distribution

sulfate and nitrate compounds and for sea salt (fS(RH), fL(RH) and fSS(RH) respectively).

Testing of the new algorithm reveals that, in most regions of the country, the new

equation gives somewhat higher light extinction, especially on the worst visibility days. But

compared to the old equation, the relative percentage of extinction attributed to the various PM

components is nearly unchanged. Therefore, the revised equation is not expected to make a

large difference in the rate of visibility changes resulting from potential control strategy

simulations. However, the new equation could lead to differences in the relative change in light

extinction predicted by the models. Either of the IMPROVE equations are acceptable for use in

reasonable progress analyses, although States should provide documentation concerning the

choice of equation, especially in situations where large differences are noted between the new

and old71.

71Both algorithms can be independently used to estimate changes in extinction between a

base period and a future year. But the same algorithm needs to be used in each calculation

(don’t use the old algorithm to calculate base extinction and the new algorithm to calculate

future extinction or vice versa). Also, the same algorithm should be used to calculate the

n701 - n702 - n703 - n704 - n705 - n706 - n707 - n707 - n709 - n710 - n711 - n712 - n713 - n714 - n715 - n716 - n717 - n718 - n719 - n720 - n721 - n722 - n723 - n724 - n725 - n726 - n727 - n728 - n729 - n730 - n731 - n732 - n733 - n734 - n735 - n736 - n737 - n738 - n739 - n740 - n741 - n742 - n743 - n744 - n745 - n746 - n747 - n748 - n749 - n750

castellano: DISPER CUSTIC DESCAR RADIA italiano:

castellano: DIS CUS DES RAD english: DIS CUS DES RAD

português: DIS CUS DES RAD italiano: DIS CUS DES RAD