41b
I-. 1. WIPPFRMANN
--_ *
\
--__
_ -
I
I
I
- sldmnory
.._ non. stollonory
-- i
-
I
1
L
' 10
F'Ic;. R. The diflerencca of the vertical K,,,* profiles in the nonstaiionary case compared with
the corresponding stationary caws ( i t . ciscs having the same thernial siraiitication).
It is interesting to compare the turbulent diffusion coefficients with those
which are obtained in the stationary case having the same thermal
stratification p. Figure 8 shows the result of such comparisons. The nonstationary diffusion coefficients are srnaller than the corresponding stationary
ones at noon, but they are larger at night.
5. TtiE ERROR IN THE MAXIMIJM GRC)IIND CONCENrRA1.ION IIlJE TO
NEGI.E('TING NONSTATIONARITS
The concentration S(x. y, 0 ) at the ground has a maximum in the stationary casc when material is dispersed from an elevated (continuous) point
soiirce at z = 11. I1 is given by the usual formula (K-theory)
(13)
S
,
,
,
= (2Q/ed1~ii)[k,/k,]'