246
WILLIAM B. LARGE
winds below 10m/s such a representation predicts a much more rapid
increase in C DN than is supported by data, including those used by
Garratt (1977) and Fig. 3. More recently, Smith (1988) suggested adding
the two z o expressions (35) and (36), although there is no evidence that
addition is the physically correct operation:
z o = α s ν u
∗−1 + α c g u
∗2 .
(37)
In contrast, manipulating (34) leads to an exponential dependence:
z o = 10m e
u ∗ /(κ U N ) = 10m e
√
C DN /κ .
(38)
Figure 4. Time series of transfer coefficients CDN (top panel pluses) and CHN (top
panel triangles) and corresponding wind speed, wind direction, air temperature, SST
and stability (z/L).
All large data sets of measured C DN display considerable scatter at
any given wind speed, but the standard deviations of Fig. 3 show that
WILLIAM B. LARGE
winds below 10m/s such a representation predicts a much more rapid
increase in C DN than is supported by data, including those used by
Garratt (1977) and Fig. 3. More recently, Smith (1988) suggested adding
the two z o expressions (35) and (36), although there is no evidence that
addition is the physically correct operation:
z o = α s ν u
∗−1 + α c g u
∗2 .
(37)
In contrast, manipulating (34) leads to an exponential dependence:
z o = 10m e
u ∗ /(κ U N ) = 10m e
√
C DN /κ .
(38)
Figure 4. Time series of transfer coefficients CDN (top panel pluses) and CHN (top
panel triangles) and corresponding wind speed, wind direction, air temperature, SST
and stability (z/L).
All large data sets of measured C DN display considerable scatter at
any given wind speed, but the standard deviations of Fig. 3 show that