39
is defined as the fully turbulent region where the vertical turbulent
fluxes of mass and energy do not change appreciably from that at the
surface (Brutsaert, 1982). In other words, the vertical flux of mass
and energy is constant.
According to Brutsaert (1982), Prandtl introduced the use of the
logarithmic wind profile law into meteorology in 1932. This is an
approximation of the wind velocity profile in the surface sublayer
WS = -Hi- In (-!-) (2-42)
K Zg
where
WS
=
wind speed [ m*s-1]
U*
=
shear velocity
r V2
v P '
ZO
=
surface roughness height [ m ]
k
von Karman constant [dimensionless]
To
s
shear stress at the surface [N*m~2]
P
s
density of air [kg*m'3]
According to Sutton (1953), for practical purposes, the shear velocity
can be estimated as
U*
WS
Iff
(2-43)
The bulk mass transfer within the surface sublayer is defined by
Qm = Ce,rWSr (Pys ^vr)
(2-44)