Geoscience Reference
In-Depth Information
Rossby-Similarity Parameters
20
15
B
10
5
0
-
5
A
-
10
-
15
0
50
100
150
200
250
300
µ
*
= u
*0
/fL
0
Fig. 4.10
Comparison ofsimilarityestimatesofthebuoyancy dependent stabilityparameters with
empirical estimates from Clarke and Hess (1974) using geostrophic wind and surface fluxes mea-
sured over level ground inAustralia
4.3.2 The Rossby-Similarity Parameters for Stable Stratification
Clarke and Hess (1974) investigated empirically the relationship between
geostrophic wind and surface flux conditions over flat terrain in Australia (the
Wangara data). Their results are plotted in Fig. 4.10 as a function of the ratio of
the planetary scale to the Obukhovlength (their definition differs by a factor of
κ
),
alongwiththefunctionsderivedfrom(4.36).
4.4 Ice-Edge Bands
The readermay wonderatthe importanceof showinghowthe similarity theoryfor
theundericeboundarylayersatisfies someoftheatmosphericconstraintsdiscussed
above.Afterall,asshowninFig.4.7,itwouldtakeunrealisticallylargemeltratesto
approachthelevelsof
µ
∗
seenroutinelyintheatmosphere.Thisistrueforstatically
unstable conditionsas well. In general, the diurnal buoyancycycle observed in the
mid-latitude atmosphere is much more intense in its impact on the boundary layer
than in the ocean. For pack ice away from marginal ice zones or large polynyas,
