where is the non-dimensional distance with

uand F

v X(x u z) given by effective parameters,v i= σ~ / ~where "

= zi /l, andziis the mixed layer height.Based on a preliminary comparison of F

ya(eq. (77)) with selected stable and convective casesfrom the Prairie Grass experiment (Barad 1958) " was found equal to 78 and

pequal to 0.3. Assuch, " is treated as a fitting parameter. In later comparisons against the full Prairie Grass data

set (Figure 17), eq. (77) tended towards the lower envelope of this widely scattered data (i.e.,

lateral dispersion estimates are on the lower end of the distribution of measurements). However,

the preliminary values of " (= 78) and

p(= 0.3) produced good agreement between AERMODconcentration predictions and observations (Brode 2002). Therefore, these preliminary values

were retained in AERMOD, and eq. (77) applies for the calculation of F

yafor all plumes in boththe SBL and CBL.

Figure 17: Lateral spread (Fy) as a function of non-dimensional distance

(O). The data is taken from the Prairie Grass experiment (Barad

1958).

The ambient component of the lateral dispersion for the penetrated source, i.e. a source which

has been released below

zi, but penetrates above, is calculated using eq. (77) withhesset equal to

hep(the height of the penetrated source). However, for the injected source, i.e. source releasedabove

zi, no substitution is needed since these sources are modeled as a stable source.To account for the increase in the turbulence length scale and hence the Lagrangian time scale

with release heights greater than that at Prairie Grass, " is scaled as follows:

n951 - n952 - n953 - n954 - n955 - n956 - n957 - n958 - n959 - n960 - n961 - n962 - n963 - n964 - n965 - n966 - n967 - n968 - n969 - n970 - n971 - n972 - n973 - n974 - n975 - n976 - n977 - n978 - n979 - n980 - n881 - n982 - n983 - n984 - n985 - n986 - n987 - n988 - n989 - n990 - n991 - n992 - n993 - n994 - n995 - n996 - n997 - n998 - n999 - n1000

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