15.0 What Should Be Considered When Selecting The Size And

Horizontal/Vertical Resolution Of The Modeling Domain?

A modeling domain identifies the geographical bounds of the area to be modeled. The

appropriate domain size depends on the nature of the strategies believed necessary to meet the

air quality goal. This, in turn, depends on the degree to which air quality observations suggest

that a significant part of an observed exceedance is attributable to regional concentrations which

approach or exceed levels specified in the NAAQS. The choice of domain size is also affected

by data base management considerations. Generally, these are less demanding for smaller


Horizontal resolution is the geographic size of individual grid cells within the modeling

domain. Vertical resolution is the number of grid cells (i.e., layers) considered in the vertical

direction. The choice of suitable horizontal and vertical resolution depends on spatial variability

in emissions, spatial precision of available emissions data, temporal and spatial variation in

mixing heights, the likelihood that mesoscale or smaller scale meteorological phenomena will

have a pronounced effect on precursor/pollutant relationships, data base management constraints,

and any computer/cost constraints.

We begin this section by discussing factors States/Tribes should consider in choosing

domain size. Next, we address the selection of horizontal grid cell size and the number of

vertical layers. We conclude by discussing factors affecting the decision on the size and

resolution of coarse scale and fine scale grids within a nested model.


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