430
J A M t S h. AhCilil I.
been shown by tlirugcn (1960) thitt thc douhlc-difli.rcntiatic~n requirement
introduccs considerable uncertainty in the results obtained.
When /I is plotted ;IS ;I tutiction of turhulencc intensity. it is found thiit the
Oklahoma ('ity "rural" trace of Fig. 6 (including thc normali7;ition for
urban clkcts) is pretty well bracketed by tlie values obtained from inass
tracer experinients by Hay and Piisquill (1959). Pnnofsky (1962). and
Haugcn (1966). with Haugen obtaining p values about two-thirds as large.
and Hay and Pasquill and Panofsky values about five-fourths as large (at a
given turbulence intensity) as the values obtained at Oklahoma City. None
~f thb above data i\grce with the results of Islitzcr and D\tnibiltlId (1%2)
since they found esscntially no vnriation of /j with turbulence intcnsitj'. 11)
comparisons of this kind it should be kept in mind that the mass-tracer
cxperinicnts generally yield /j values for the lateral dimension whereas thc
tetroons. as used hcrcin. yield them for the vertical dimension. and there is
no guarantee that /I is the same in thc two directions.
5. ~ O N C l ~ l ~ S l O N
The Oklithonla <'ity tetroon and tower data are of high quality. but
nevertheless, unrepresentative values of the Lagrangian- Eulerian scale ratio
/I have k e n oht;iined because. when the tower is downwind o f the city, the
tower data always reflect the relatively high frequency oscillations set up by
the urban roughness elements whereas the tetroons spend only a brief time
within this urban boundary layer. Because of the uncertainty surrounding
tlic procedure used herein to correct for the urban influence on 11, attempts
will bc made to isolate these portions of the tetroon trajectories which might
reasonably he expected to be influenced by the city. and to obtain representiitive Lagrangiitn urban spectra for comparison with the Eulerian urbitil
spcctrs measured on the tower. In gcneral. it is belicved desirable lo aniilvlc
illid understnnd these observations more fully before embarking on iiny lieu
tetroon experiments aimed at eviiluatiori of the Lagrangian Eulerian scitle
r;t t io.
A ( X N ~ W I . I : I X ~ M E N T S
'l'liis cupriinctii crrultl iioi Iiiivc hccn carried out without thc ahle iibsibtiincc 11lC. H Dicksoti. <;. Wliiic. I.. Wctidcll. ( i . Siiirt. J. Young. iild ti. Boen ofthr Air Resources I'icld Rcaciirch
Oliicc. Niiiiitnal Hciict~ir 'l'csiing Stiitiou. Idaho kitlls, iiiid (If W . Hocckcr and A . Giarrusw 01
thc Air Hc\tiurccs l.;ihor:itorics' of1iL.e in Silvcr Spring. Md. Ci tlcrhert (t1ieii)olthc latter ot'licc
ovcrww i he ;icqiiisitiirn (11 the tower ilatii :in11 its reduction. 0 14. Pach ha.; pro\itlcd encour;igcinciit ;iirtl pci iiii~*iii cointiicnts throughtriit the aniilysis. and I . t'iisquill iiiicovcrcd ;I scrioii\
ci-ror 111 the iiiictprci:itioii or the tower spctrii and provided u d i i l pirid;ince ctmcerning the
iiiiitcriiil \+orthy 111 pre\eiitation.
J A M t S h. AhCilil I.
been shown by tlirugcn (1960) thitt thc douhlc-difli.rcntiatic~n requirement
introduccs considerable uncertainty in the results obtained.
When /I is plotted ;IS ;I tutiction of turhulencc intensity. it is found thiit the
Oklahoma ('ity "rural" trace of Fig. 6 (including thc normali7;ition for
urban clkcts) is pretty well bracketed by tlie values obtained from inass
tracer experinients by Hay and Piisquill (1959). Pnnofsky (1962). and
Haugcn (1966). with Haugen obtaining p values about two-thirds as large.
and Hay and Pasquill and Panofsky values about five-fourths as large (at a
given turbulence intensity) as the values obtained at Oklahoma City. None
~f thb above data i\grce with the results of Islitzcr and D\tnibiltlId (1%2)
since they found esscntially no vnriation of /j with turbulence intcnsitj'. 11)
comparisons of this kind it should be kept in mind that the mass-tracer
cxperinicnts generally yield /j values for the lateral dimension whereas thc
tetroons. as used hcrcin. yield them for the vertical dimension. and there is
no guarantee that /I is the same in thc two directions.
5. ~ O N C l ~ l ~ S l O N
The Oklithonla <'ity tetroon and tower data are of high quality. but
nevertheless, unrepresentative values of the Lagrangian- Eulerian scale ratio
/I have k e n oht;iined because. when the tower is downwind o f the city, the
tower data always reflect the relatively high frequency oscillations set up by
the urban roughness elements whereas the tetroons spend only a brief time
within this urban boundary layer. Because of the uncertainty surrounding
tlic procedure used herein to correct for the urban influence on 11, attempts
will bc made to isolate these portions of the tetroon trajectories which might
reasonably he expected to be influenced by the city. and to obtain representiitive Lagrangiitn urban spectra for comparison with the Eulerian urbitil
spcctrs measured on the tower. In gcneral. it is belicved desirable lo aniilvlc
illid understnnd these observations more fully before embarking on iiny lieu
tetroon experiments aimed at eviiluatiori of the Lagrangian Eulerian scitle
r;t t io.
A ( X N ~ W I . I : I X ~ M E N T S
'l'liis cupriinctii crrultl iioi Iiiivc hccn carried out without thc ahle iibsibtiincc 11lC. H Dicksoti. <;. Wliiic. I.. Wctidcll. ( i . Siiirt. J. Young. iild ti. Boen ofthr Air Resources I'icld Rcaciirch
Oliicc. Niiiiitnal Hciict~ir 'l'csiing Stiitiou. Idaho kitlls, iiiid (If W . Hocckcr and A . Giarrusw 01
thc Air Hc\tiurccs l.;ihor:itorics' of1iL.e in Silvcr Spring. Md. Ci tlcrhert (t1ieii)olthc latter ot'licc
ovcrww i he ;icqiiisitiirn (11 the tower ilatii :in11 its reduction. 0 14. Pach ha.; pro\itlcd encour;igcinciit ;iirtl pci iiii~*iii cointiicnts throughtriit the aniilysis. and I . t'iisquill iiiicovcrcd ;I scrioii\
ci-ror 111 the iiiictprci:itioii or the tower spctrii and provided u d i i l pirid;ince ctmcerning the
iiiiitcriiil \+orthy 111 pre\eiitation.