The URBANOPT keyword on the CO pathway in AERMOD, coupled with the URBANSRC

keyword on the SO pathway, should be used to identify sources to be modeled using the urban

algorithms in AERMOD (EPA, 2004b). To account for the dispersive nature of the “convectivelike”

boundary layer that forms during nighttime conditions due to the urban heat island effect,

AERMOD enhances the turbulence for urban nighttime conditions over that which is expected in

the adjacent rural, stable boundary layer, and also defines an urban boundary layer height to

account for limited mixing that may occur under these conditions. The magnitude of the urban

heat island effect is driven by the urban-rural temperature difference that develops at night.

AERMOD currently uses the population input on the URBANOPT keyword as a surrogate to

define the magnitude of this differential heating effect. Details regarding the adjustments in

AERMOD for the urban boundary layer are provided in Section 5. 8 of the AERMOD model

formulation document (Cimorelli, et al., 2004).

Section 7.2.3 of the Guideline on Air Quality Models (EPA, 2005b) provides the basis for

determining the urban/rural status of a source. For most applications the Land Use Procedure


n201 - n202 - n203 - n204 - n205 - n206 - n207 - n208 - n209 - n210 - n211 - n212 - n213 - n214 - n215 - n216 - n217 - n218 - n219 - n220 - n221 - n222 - n223 - n224 - n225 - n226 - n227 - n228 - n229 - n230 - n231 - n232 - n233 - n234 - n235 - n236 - n237 - n238 - n239 - n240 - n241 - n242 - n243 - n244 - n245 - n246 - n247 - n248 - n249 - n250


   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