A LAKE BREEZE INDEX


by
W. Gale Biggs
Maurice E. Graves
Technical Report No. 5
ORA Project 03632
NATIONAL SCIENCE FOUNDATION GRANT G-11404
College of Engineering
Department of Engineering Mechanics
Meteorological Laboratories
and
Institute of Science and Technology
Great Lakes Research Division
Special Report No. 15


THE UNIVERSITY OF MICHIGAN
ANN ARBOR, MICHIGAN
April 1962








ABSTRACT


Since the mathematical equations
describing the lake breeze phenomenon are
too complex to yield exact solutions, approximation techniques are often used. To
obtain the important parameters upon which
the solutions depend, a dimensional analysis
is then employed. The study shows that two
dimensionless parameters describe the balance
of forces that distinguish between lake
breeze days. A lake breeze index is established and a critical value is found. If a
narrow transition zone is recognized, then
the lake breeze index has an accuracy of
97 per cent.




ACKNOWLEDGMENTS
The writers are deeply indebted to
Professors E. Wendell Hewson and Walter R.
Debler for their cooperation and guidance
in undertaking and developing this study.
They also wish to thank Mrs..Anne C. Rivette
for careful preparation of the manuscript.




TABLE OF CONTENTS


Page


ABSTRACT
ACKNOWLEDGMENTS
1. Introduction
2. Development of a Lake Breeze Index
3. A Critical Lake Breeze Index
4. Test Criteria
5. Analysis of the Data
6. Discussion
7. Summary
REFERENCES
APPENDIX I
APPENDIX II


1
2
6
8
10
21
29
30








1. INTRODUCTION


The physical concept of a lake breeze may be stated
as a heat transfer problem. During periods of insolation
the land surface is heated and its temperature increases,
whereas the water surface remains at a relatively constant
temperature due to its thermal characteristics. The surface
temperature influences the overlying air and as a result
there is warmer and less dense air over land while over the
water the overlying air is cooler and more dense. Near the
shore line between the two surfaces, a pressure gradient is
established due to the buoyant effects created by the temperature differences. Thus if the prevailing synoptic conditions
are such that the gradient wind is lightL the buoyant force
is the dominant force and a lake breeze is established.
The equation of motion, the energy equation, and
the equation of continuity are used to establish the general
properties of the.-motion and to calculate the unknown physical
variables [2,3,4,5,7]. However, the problem formulated in
exact mathematical terminology is too complex to solve analytically.  The results of a theoretical analysis then depend


1




on approximate equations. An investigation of this character
should be initiated by finding out the important mathematical relationships between the properties that govern the
phenomenon. A preliminary analysis and choice of a system of
nondimensional parameters is made possible by dimensional
analysis and similarity theory.
2. DEVELOPMENT OF A LAKE BREEZE INDEX
Consider that the following function of fundamental
quantities describes the lake breeze
0 =   f(U, 2, h, P, K, C, k, p, T, AT, p, g)
m   p
~ =   a function that describes the lake breeze
U  =  a characteristic velocity
2 =   a characteristic length
h  =  a characteristic height
=  coefficient of expansion of air
K   = eddy diffusivity
m
C   = heat capacity of air
k  = thermal conductivity of air


2




p  =  density
T  =  a characteristic temperature
AT  =  difference between the characteristic
temperature and the lake temperature
p  =  pressure
g  =  gravity
Application of Buckingham's Theorem [9] yields the
following quantities
h  _     AT     U2     kT         U~     p    gi
- =,3     P T T  K g  pU2 ' U2
p                   m
Motions which are caused primarily by the density
gradients created by temperature differences are termed
"natural" as distinct from those "forced" on the stream by
external causes. In natural flows, the Reynolds number,
UW/v   (= U2/K    K /v), where  v  is the kinematic viscosity,
m    m
and the Euler number, p/pU2, are of little importance
because the solutions are nearly independent of their values.
Thus they can be neglected when compared to the other quantities
The Prandtl number,   J C /k, where  pL is the dynamic
P
viscosity, and the Grashof number,   g P T 23/V2    can-be


3




obtained by suitable combinations of the above parameters.
The Prandtl number is practically constant for air    (P = 0. 7)
so it is neglected. The Grashof number is considered important
[8] in natural flows, so it is retained.
Thus the important ratios are
h        AT     U2     kT    g   T K 3
-  =  q   T ' C  T t Ujp /      K 2
L p               m
Special attention is called to two parameters, namely,
U2/C  T  and   AT/T, which contain readily measurable quantities.
p
C   for air is   1.003 joules/gm ~K. T    and  U  are obtained by
selecting a site uninfluenced by the lake breeze effect and
therefore representative of the temperature and wind velocity
for the local area.   AT  is simply the difference between the
land temperature and the lake water temperature.
Dividing  U2/C   T  by  AT/T  gives a new parameter,
p
U2/C  AT. This parameter is the dominant one, since it combines
p
the two most important variables, wind speed and temperature difference. A closer inspection shows this to be a ratio between
the inertial force and the buoyancy force. The inertial force
is given by the wind speed and the buoyancy force is given by
the temperature difference.   The writers have termed this ratio


4




of forces the "Lake Breeze Index" (hereinafter referred to
as the "L-B Index").*
The L-B Index expresses a relationship between the
inertial and buoyancy forces and determines which is dominant.
Thus, if the inertial force is relatively large, it can be
asserted that there will not be a lake breeze. If, however,
the buoyancy force becomes large, the stage is set for the
establishment of a lake breeze. The critical value and the
limitations of the L-B Index will now be explored.
The dimensionless ratio,  U /Cp AT, was referred to
by Schlichting [8] as the Eckert number, following a suggestion
by Professor E. Schmidt. However, in that case it was used to
show.that the frictional heat and the heat due to compression
was important for the calculation of the temperature field when
the free stream velocity,  U   /, was so large that the adiabatic
temperature increase was of the same order of magnitude as the
prescribed temperature difference between the body and the
stream. Thus,
U 2/C (AT)   =  2 (AT)  /(AT)
00  p  o           ad
where
(AT)o  =  the temperature difference between the body
and the stream
(AT)    =  the temperature change due to compression of
ad     the high speed flow
The work of compression and that due to friction become
important when the free-stream velocity is comparable to the
speed of sound. Therefore, the above interpretation of the
Eckert number is not relevant to the present study.


5




3. A CRITICAL LAKE BREEZE INDEX


In finding the critical value separating lake breeze
days from non-lake breeze days, a previous statistical
analysis [6] of two months (June and July, 1957) of climatological data from. the Enrico Fermi Nuclear Reactor site
located on the western shore of Lake Erie (Fig. l) was used
as a verification criterion and the L-B Index was compared
to it. A critical value of three was chosen since all days
with a L-B Index greater than three were-seen to be non-lake
breeze days and all days when the L-B Index was between zero
and three were lake breeze days.
To test the system, information gathered during the
following months was used as independent data: May and
August, 1957; May, June, July and August, 1958 and 1959. To
compute the L-B Index, a maximum temperature and mean daytime wind speed were sought which were representative of
conditions near the lake shore with the lake effect removed.
A desirable source seemed to be Detroit Metropolitan Airport,
which is located about.19 mi NNW of the reactor site. However, hourly observations from Detroit Metropolitan only
dated back to the fall of 1958, so the Willow Run Airport
just east of Ypsilanti, Michigan, was selected. It is located
about 24 mi NW of the reactor site.


6




N
/                             LAKE ST. CL
DETRO/T A
WILLOW RUN    METROPOLITAN
AIRPOR I      APOrC A NADA
GROSSE ILE
NAVAL AIR STArTI
-SITE
LAKE ERIE
\    evot/on 572 ft
\  TOLEDO'                                  /         /
EXPRESS
Figure 1.    Area map of Enrico Fermi Nuclear Reactor site,
Willow Run Airport, and surroundings.


-AIR


7




Referring again to the parameters, U2/C   AT, U2/C  T
P          P
and AT/T, the maximum temperature (~K) for a particular day
was taken as T   and the average hourly wind speed (m/sec)
between 1000 and 1600 hr as U. Since the buoyant force acts
vertically and the inertial force acts nearly horizontally,
regardless of wind direction, U was computed solely from
wind speed information. The lake temperature was taken from
data at the Monroe city waterworks, which have been found to
be representative of the lake water temperature in the western
portion of Lake Erie [1].  Putting these values in the parameter,
U2/C AT, an index number was obtained for each day in the
p
twelve-month period from the three summer seasons.
4. TEST CRITERIA
The synoptic criteria for selection of days with a lake
breeze influence were as follows:
1. Gradient wind not from the SE quadrant.
2. Temperature of the land greater than the
temperature of the water.
3a. Surface wind changed to the SE quadrant while
the temperature of the land was greater than


8




lake temperature, and returned to a gradient
condition after sunset, or
3b.  Surface wind changed at least 40~ to a
direction from NNE clockwise to SSW due to
thermal influence, then returned to a gradient
condition.
4. No frontal passages occurred between 1000 and
1600 hr.
If criterion 1 or 4 was not fulfilled, the day was
excluded entirely from the analysis. Each day accepted for
consideration was given a L-B Index, based upon dimensional
analysis, and the outcome of the synoptic analysis was then
compared with it. Since the winds were averaged over seven
observations, the first few observations were sometimes low
enough to place the case in the lake breeze category. Also,
the maximum temperature occasionally occurred too early in
the day to be representative. These limitations seem to be
the principal ones of the system.
In summary, the procedure was to analyze each day by
two independent methods. An analysis of the climatological
data established the occurrence of a lake breeze, if any.
Then a numerical computation of the L-B Index was compared


9




to it. The strength of the lake breeze was- not considered;
however, one could infer the probable strength of the lake
breeze from the size of the L-B Index.
5. ANALYS I S OF THE DATA
Of 369 total days in the 12 summer months, 43 days
were eliminated because of an onshore gradient flow, 25 days
were dropped due to missing data, and 15 days were excluded
because of frontal passages. Of the 286 days analyzed, there
was disagreement between the two categories on but 20, hereinafter referred to as "Unstable Parameter Days."   Table 1
gives a detailed breakdown, by months, of how the days were
classified. This table shows August to be the month during
which almost 50 per cent of the unstable cases occurred.
Fig. 2-5 relates the dimensionless parameters, AT/T
and  U2/C  T, on a monthly basis for 1957-1959, inclusive.
p
The lake breeze days are observed to lie to the right of the
line of demarcation corresponding to   U2/C  AT = 3    and the
p
non-lake breeze days to the left, excepting the 20 unstable
parameter days. Only three of the latter cases are seriously
far removed from the line, one of them being in June and two
in August.


10




TABLE 1
Classification of all days, month by month, in the period of investigation


1957
May  Jun  Jul Aug


1958
May Jun Jul Aug


May




1959
Jun Jul


Aug


TOTAL


Gradient
Cases
Frontal
Passages
H-     Missing
HData
Analyzed
Cases
Totals
Lake Breeze
Cases
Unstable
Parameter


4
2
25
31
3


1
1
28
30
10
1


2
1
28
31
11


2
2


5
2


27
31
8
4


24
31
3
2,


3
1
26
30
8
3


4
1
26
31
9
1


23
31
7
4


23
31
3
1


6
2


6
2


5
1
24
30
7
2


4     1
2   23
25     7
31   31
8     1
1


43.15
25
286
369
77
20




___ _ I ___ __ _YI I _I_


CM
x
Xe
~- |
-al'o
n~


a
20                    ~
16          o         ~           /
0        0
0          0
1 8
0  0
a      a~
10
0   -
12 -
10
/             o-Lake Bree
0
8                          o   a-Non-Loke
x-Unstable
Doy
6
0
4              0
2 -0


I- I


e Doay
Breeze Day
Parameter


I


0


I


i                         I


I


I


I


_~  _  -            L  --  a  -L,  II  - - II- - CI~ —LII-II-~I  41 --


I   2    3    4   5    6    7   8


Figure 2.


AT
T  x i2 —
A plot of AT/T   versus  U2/C  T, representing
buoyancy forces versus inertial forces, respectively,
at the reactor site during the combined Mays for
1957-1959. The critical value, U/Cp AT = 3.0, is
represented by the:diagonal line.


12




_ _


22k

0          0
0
O
Q


20


a
0


O


18 -

0


B


0


161


14
t l4
N
10
x   12
1F ~


10o


81


-             /
-     ~.   o   /   0
aa
0    0
ax 0
0       /         0
-        x
0   /
x
o                0
0    0         0
a0
0       0             0
o       0
0         0
0
I    I    I    I    I


6


41


2
0
Figure 3.


o-Lake Breeze Day
o-Non-Lake Breeze Day
x-Uns table Parameter
Day
I    I


I    2    3   4    5    6    7    8
AT   -2


A plot of AT/T   versus U2/Cp T, representing
buoyancy forces versus inertial forces, respectively,
at the reactor site during the combined Junes for
1957-1959. The critical value, U2/Cp AT = 3.0, is
represented by the diagonal line.


13




0


22


0


20 -

0


a


0


0 0


0


IJ8


0
0   o


161


141


0o 12
8


I


0     0          /
0  0 0/
B            /
0         /
o
0
~     o /
0
o  /
0    /
0  0
0o       x
0     0
~  ~0
0
0  o  0
00  0
/      0  o     o0             x0
00         0
0
0/   0
1  1~  ~


6


4
2
0


L a ke Breeze Day
Non - Lake Breeze Day
Unstable Parameter
Day


I —                                                                                  i                                 I                                 I






~                              I                               II


1    2    3    4     5
T xlO


6    7     8


Figure 4.


A plot of AT/T   versus U2/Cp T, representing
buoyancy forces versus inertial forces, respectively,
at the reactor site during the combined Julys for
1957-1959. The critical value, U2/Cp AT = 3.0, is
represented by the diagonal line.


14




I


20
18


0


0


141


t
io      12
Cm
0    10
8
6


0     oO 0
x
-  0
00
a
a~ o               y  o
0  0           /
0   ~
0
o          /
0
0
O     00
O       Xo
/      Xo
o           o
0 0          0
x0
/              o-Lake A
0
/   o                   x-Unstay
I     I     01I


41


21


Freeze Day
oke Breeze Day
V/e Parameter


C


II


I


I


I


I


M r


F


I


2


3


4


5


6


7


Figure 5.


IAT    2 -T
A plot of AT/T   versus  U2/Cp T, representing
buoyancy forces versus inertial forces, respectively,
at the reactor site during the combined Augusts for
1957-1958 and August 1-8, 1959. The critical value,
U2/C  AT = 3.0, is represented by the diagonal line
p


15




Table 2 gives the verification scores for Fig. 2-5,
combined, in percentages of the total number of analyzed cases.
TABLE 2
Classification of Analyzed Cases
Percentage of Total
Stable parameter days......     92
Unstable parameter days.................  8
TOTAL............  100
Fig. 6-9 show the relationship between the L-B Index,
U2/C  AT, and the dimensionless parameter,  U2/C  T, for
P                                            p
the combined Mays, Junes, Julys and Augusts of 1957-1959.
Fig. 10-13 relate the L-B Index to AT/T   for the same combined months of these years. Between May and August, certain
trends are seen in all three kinds of scatter diagrams. First,
the number of lake breeze cases rises to a maximum in JuneJuly, then dwindles in August. Second, the points tend to
condense toward the origin in each succeeding month, reflecting
the decrease of the wind speed at Willow Run as well as the
decrease of AT. The latter decrease is attributable to an


16




_ _I


12


o -Lake Breeze Day
-Non-Lake Breeze Day
x - Unstable Parameter Day


10


0


8k

0


0


c <
I a


0


0


6k


0


0


93


0
m


0
0o
0 0
O0
0


0


4k


0
0   0  o   o~


n


H


--                             -- -.-. y


2
n,


O
0


0


x


0


0


I


o p


0
I


I                         I


I                            I


I


I


v.........II,      I.. I  1   I  ~


I


2


4   6    8    10  12
U X0 2 —
cpT




14    16    18   20     22




Figure 6.


A plot of U/Cp T    versus the Lake Breeze
Index,  U2/C  AT, at the reactor site during
the combined Mays for 1957-1959. The critical
value of U2/Cp AT = 3.0 is represented by the
horizontal line.




I AC


I                 I


o O


14k


0- Lake Breeze Day
o - Non - L ake Breeze Doay
x- Unstable Parameter Day
0


12-k


0


0


10


t


O


0


O


O


0


Co <> 8
D 8


O


0


O


0


0


0 A


0


6k


x


0


0


H
0O


O


0
D


0


4 -

0


0


cP


0


2
0


0      0  x   00
I  o oI.                          -
x      x
0 ~   00 0
Qo   0          ~8, 1      I                       I         I  L
2    4    6     8    10   12   14   16   18   20    22
U2
x1(2 —
CpT


Figure 7.


A plot of U2/Cp T   versus the Lake Breeze
Index, U2/Cp AT, at the reactor site during
the combined Junes for 1957-1959. The critical
value of U2/Cp AT = 3.0 is represented by the
horizontal line.




16


0


o-L ake Breeze Day


O


14 -

12
t 10
I   8


o-Non-Lake Breeze Day
x-Unstoble Parameter Day
0


0


co


0


0
O


0


0


0
0   0


0
0


0


6 -


0


0o


H
W~


0
0


0
0


4
2
0


0


0  0
0o    0
0


0
0


0
0


O


0   n




_5


X


X




2    4     6    8    10   12
U2
C T X    -2
p


14       16       18      20


Figure 8.


A plot of U2/Cp T   versus the Lake Breeze
Index,  U2/C  AT, at the reactor site during
the combined Julys for 1957-1959. The critical
value of U/Cp AT = 3.0 is represented by the
horizontal line.




0


14 -

0


0


O


12 -

0


O


10 -

H 8
cq
D.
0


0


0


0


0


O


6k


O


O


0


O)
0


4H


x
O


0


O v


V


2
0


o                      ~      o- Lake Breeze Day
-0 0       X
0     o 0                       o - Non-Loke Breeze Doy
00                          I        -Unstable Parameter Day
2     4     6    8     10   12    14    16    18    20
2
U     -2
CpT x 10O


Figure 9.


A plot of U2/Cp T   versus the Lake Breeze
Index, U2/Cp AT, at the reactor site during
the combined Augusts for 1957-1959. The critical
value of U2/Cp AT = 3.0 is represented by the
horizontal line.




20
18
16
14




0


o - Lake Breeze Day
o - Non-Lake Breeze Day


7


x - Unstable Porameter Day


0


0
0


I


12 -

0


10


0


8
6
4
2
0


0
0
0


0
0


0


0


0


B
13oo o


O0


0
r


Cb
-_,


0 'B
00
f-!


n

Q     LU  U U
~-.
0X 0
0
0
I    I O I     1    1~ ~01


I


2    3    4
AT   - 2
T xIO


5    6


Figure 10.


A plot of  AT/T  versus the Lake Breeze
Index,  U2/CpAT   at the reactor site during
the combined Mays for 1957-1959. The critical
value of U2/Cp AT = 3.0    is represented by the
horizontal line.


21




20
18
16




0


x


0


o-Loke Breeze Doy
-o-Non -Loke Breeze Day
x-Un stable Parameter
Day


0


2


0


14k


O0


t


12


I, a
0 10
8
6


0
0


0
0


0
0


0
0


0


0    0


0


0
x


0
0
0


0


0


0


0


0
0
Q


4
2


0
0


0
0 0


g
0
0    0~


- -- o      Am


0


0
0




00
0 0


0 0
^0
% o
93
I o


o
0    0
I    - I


0
0
1       I


0


I




I. II iI,




I


2


3    4
AT    2 -T x i0 -

5.     6


7






Figure 11.


A plot of AT/T   versus the Lake Breeze
Index, U2/C   AT  at the reactor site during
the combined Junes for 1957-1959. The critical
value of U2/Cp AT = 3.0    is represented by the
horizontal line.


22






20
18
16
14


0


o - Lake Breeze Day
o - Non-Lake Breeze Day
x- Unstable ParameterDay


0


0


0


t


12
10




0


0a
Q o


8
6
4
2
0


0
0


0
0
O0
0
0  j0o
~  n~


0
0


I
I


o
D


0
0






RP

x - 0


I   2    3   4    5   6
AT -12
T


Figure 12.


A plot of AT/T   versus the Lake Breeze
Index, U2/C   AT  at the reactor site during
the combined Julys for 1957-1959. The critical
value of U2/Cp AT   =  3.0  is represented by the
horizontal line.


23




20
18
16




O


o - Loake Breeze Doy
o - Non-Lake Breeze Day
x - Unstable Parameter Day


0


141


0


0
a
G


12
10


0
0


0


0
G
o


8


0


0
0 0


6
4
2
0


0
0
-r


x
x


O


0


n


-r r            VMM


' - X  'v
0  0   0
o  o x
0       0
0      00
1    I   I


0
0


0


I


I


I                         A ~                      &                         A                         I


I


2    3   4    5
g x F2




6


Figure 13.


A plot of AT/T   versus the Lake Breeze
Index, U /Cp AT   at the reactor site during
the combined Augusts for 1957-1959. The critical
value of Ua/Cp AT = 3.0   is represented by the
horizontal line.


24




annual rise in lake water temperature of at least 10~C
between May and August.
Appendix I summarizes the computation of the three
dimensionless parameters for each month investigated.
6. DISCUSSION
Prominent on the graphs representing June is one case
when the parameters were notably unstable. This day's L-B
Index was 18.0, but a lake breeze occurred at Monroe from 1300
to 1500 EST. A comparison of Willow Run wind speeds with those
of Toledo indicate that local effects were responsible for the
large discrepancy, viz., Willow Run winds at 12 kt were double
the values of the Toledo wind speeds. This difference was
magnified by the  U2  term in the L-B Index, so that the
parameter calculated in a similar way for Toledo gave a margina
value of 3.1.
The temperature difference between the Willow Run
maximum and the lake temperature for this day was but 4~F.
Because of local variations between Willow Run and the shore
line and the problem of representativeness, errors in  AT  of
about 2~F may be expected.  Then if the observed value of AT


25




is less than 6~F, the error in the  AT term would be comparable to the measured  AT. If the parameter, AT/T, is
less than  10-2, the L-B Index tends to be unstable.  However,
in most of the other cases involving  AT/T < 10-2, the temperature was not strongly influenced by local effects and it was
representative of the area conditions. All of the other unstable cases had a L-B Index of 6.2 or less.
As was pointed out earlier, the critical value for the
L-B Index was chosen to be 3.0. This gave an accuracy of 92
per cent. If, however, the region between 2.7 and 3.2 is
chosen as a transition zone, the accuracy of the system would
then be 97 per cent. Another item of interest is the fact that
the number of occurrences of lake breeze days when the L-B
Index was greater than three is less than the number of occurrences of non-lake breeze days when the L-B Index was three or
less. Of the 20 unstable cases, 35 per cent were greater than
three, while 65 per cent were three or less. Thus the system
distinguishes non-lake breeze days somewhat better than lake
breeze days. Appendix II gives a summary of the computation
of the dimensionless values for each unstable day.
An outstanding feature seen in the data for days with
unstable parameters is the effect of local space and time
variations in the surface wind speed. For example, on May 15,


26




1958, increasing offshore winds at the reactor site stopped
an incipient lake breeze. Such an increase in wind speed
also occurred at Toledo, but the L-B Index at Willow Run was
only 2.1. Half of the nonmarginal cases falling outside-the
transition zone in Figs. 2-13 are similar to this example.
In the remaining five unstable cases, the Willow Run data were
evidently unrepresentative of reactor site conditions due to
more subtle effects of cloudiness and precipitation, or to a
stronger basic flow at Willow Run than along the lake.
During the day, the value of the eddy diffusivity,
K    over the lake surface is generally less than    K   over
m                                                    m
the land, and the air over the lake would be expected to be
relatively stable close to the surface. However, in the L-B
Index, no value of   K   is needed to distinguish between the
m
two cases of lake breeze or non-lake breeze.    Also absent are
the coefficient of expansion of air, and   k, the thermal
conductivity. These parameters are but indirectly involved
because of the method used to select the numerical values-for
U  and  T. This implies that the maximum temperature for the
day is a good measure of the energy available for thermal
effects. Thus it seems that the method of selection for T
and U incorporates the other effects, and their influence
is reflected in these values.


27




The prevailing winds in the southeastern Michigan
area are southwesterly. Therefore, the meteorological
measurements are usually taken from air that has had a land
trajectory.  Applying the L-B Index to a location where the
prevailing winds are off the water would probably increase
the instability of the parameters, because a representative
temperature and wind speed that has not been influenced by
the water mass would be difficult to find. This method
would therefore be expected to produce best results when the
air is not influenced by a water surface. When tried at
another locality, the critical value of the L-B Index may
need modification, for the local effects may well be different.
Since the L-B Index can separate the lake breeze
4ays from non-lake breeze days successfully, it is expected
that it can also distinguish land breeze that occur at night
when the L-B Index would be negative. However, a different
criterion for selecting the characteristic temperature and
wind speed would be required. This effect was not explored
in the present study.


28




7. SUMMARY


A dimensional analysis yielded a ratio (L-B Index)
that was representative of the balance of forces that
control the establishment of a lake breeze. The inertial
force,  p U2/2, and the buoyant force,  p g g AT, when
taken as a ratio, gives  U2/2g p AT, but g   is constant
over the small vertical extent of the lake breeze and'
is constant over the range of temperatures involved. Thus
the ratio is controlled by the two terms,  U2 and   AT.
For this reason, the L-B Index is representative of the ratio
of forces.
The limitations of the L-B Index are twofold in
nature.  First, a frontal passage may occur during late
morning or afternoon hours; second, the observations from the
inland station may occasionally be unrepresentative of the
lake shore conditions with the lake effect removed.
A critical value for the L-B Index was found to be
3.0.  If a transition zone between 2.7 and 3.2 is recognized,
then the procedure has an accuracy of 97 per cent in the test
per iod.


29




REFERENCES


1. Biggs, W. G., 1960: A Characteristic Water Temperature
for the Western Basin of Lake Erie (Unpublished
report).
2. Defant, F., 1951: Compendium of Meteorology, Amer. Met.
Soc., p. 658.
3. Estoque, M. A., 1961: A Theoretical Investigation of
the Sea Breeze, Quart. J. Roy. Met. Soc., 87, 136-146.
4. Fisher, E. L., 1960: An Observational Study of the Sea
Breeze, J. Meteor., 17, 645-660.
5. Fisher, E. L., 1961: A Theoretical Study of the Sea
Breeze, J. Meteor., 18, 216-233.
6. Hewson, E. W., Gill, G. C., Baynton, H. W., 1959: Univ.
of Michigan Research Institute Report, 2515-3-P.
7.  Pearce, R. P., 1955:, The Calculation of the Sea Breeze
Circulation in Terms of the Differential Heating
across the Coast Line, Quart. J. Roy. Met. Soc., 81,
351-381.
8. Schlichting, Hermann, 1955: Boundary Layer Theory, New
York, Pergamon Press, 248-256.
9.  Sedov, L. I., 1959: Similarity and Dimensional Methods
in Mechanics, New York, Academic Press, 363 p.


30




APPENDIX I
A SUMMARY OF COMPUTATIONS OF THE
DIMENSIONLESS PARAMETERS








TABLE   I;
MAY 1957


T
max
(OF)


T
ake
(~OF)


U
(Kt)


u2
C T
p


10-2 X  10 -U2
AT -
AT    C AT
T       p


Day


Type


-- - ~ -- -- -- c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


86
56
47
55
61
72
78
80
79
72
57
68
78
75
71
58
50
49
49
52
59
80
72
72
71
77
58
71
75
82
78


52
53
53
53
52
51
51
51
52
54
-55
55
55
55
56
56
58
56
55
54
53
53
52
53
55
54
55
57
56
56
57


11.4
16.1
14.1
11.3
7.4
14.1
17.0
14.0
15.1
11.9
3.4
11.9
11.1
18.7
11.1
17.7
15.9
15.0
9.6
14.7
19.3
16.4
6.4
11.7
6.9
10.1


11.4
24.0
18.4
11.7
4.9
17.6
25.5
17.4
20.4
13.1
1.0
12.6
11.0
31.4
11.3
28.8
22.4
20.2
8.3
19.4
33.1
24'.8
3.7
12'.2
3.9
9.0


6.2
0.6
0.4
1.7
4.0
5.0
5.4
5.0
3.4
0.4
2.5
4.3
3.7
2.8
0.4
1.1
5.0
3.8
3.6
3.0
4.3
0.6
2.6
3.6
4.5
3.9


1.8
40.4
47.9
6.8
1.2
3.5
4.8
3.5
6.0
34.2
0.4 -2.9
2.9
11.2
29.6
25.1
4.5
5.4
2.3
6.4
7.7
41.9
1.4
3.4
0.9
2.3


F
LB
LB
G
F
LB
G
G
G


G
F


Gradient Case
Frontal Passage


LB = Lake Breeze Day
U  =  Unstable Case




TABLE II
JUNE 1957


10-2


T
max
(~F)


T
lake
(~F)


U
(Kt)


U2
C T
p


10-2
AT
T


U2
C AT
p


Day


Type


-- -- - -- -- -- ----


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30


71
66
75
83
82
82
66
70
68
84
76
78
82
86
85
94
95
89
75
81
88
91
87
68
74
83
73
69
81
81


58
58
59
59
59
59
60
60
60
60
60
61
61
62
63
64
65
66
66
67
68
68
70
70
70
70
70
69
69 -68


6.0
13.7
5.7
6.4
4.1
6.7
10.6
18.0
11.3
9.3
13.7
7.7
13.9
13.0
8.4
7.1
9.0
11.3
16.0
7.4
11.4
14.1
15.6
11.1
13.4
7.1
21.4
15.4


3.3
17.3
3.0
3.8
1.6
4.1
10.7
30.0
11.9
7.6
16.9
5.4
17.2
14.8
6.4
4.4
7.2
11.4
23.2
4.8
11.4
17.4
21.6
11.0
15.8
4.6
40.3
22.4


2.4
1.5
3.0
4.4
4.3
4.3
1.1
1.9
1.5
4.4
3.4
3.1
4.2
4.4
4.0
5.4
5.4
4.2
1.7
2.6
3.6
4.2
3.1
0.7
2.4
0.6
2.2
2.4


1.3
11.5
1.0
0.9
0.4
1.0
9.5
15.8
7.9
1.7
5.0
1.7
4.1
3.4
1.6
0.8
1.3
2.7
13.8
1.8
3.1
4.2
7.0
15.8
6.6
8.0
18.1
9.3


F
LB
LB
LB
LB
LB
G
LB
LB
LB
LB
LB
U


G = Gradient Case
F = Frontal Passage


LB =
U =


Lake Breeze Day
Unstable Case




TABLE — III
JULY 1957


T
max
(OF)


T
lake
(~F)


U
(Kt)


U2
C T
p


10-2 X
AT
T,


10-2 x
U2
C AT
p


Day


Type


- - - - - - - - --


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


78
84
88
84
76
83
90
80
82
78
75
89
80
90
78
80
82
88
93
96
94
85
74
78
80
85
87
90
93
92
86


68
68
68
68
68
69
69
69
70
69
70
70
70
69
69
69
69
69
70
71
71
72
71
71
71
71
71
71
71
72
72


9.3
6.4
13.4
11.4
21.3
9.4
7.1
10.6
13.9
11.0
9.9
8.3
6.6
6.7
12.6
8.6
13.7
12.6
4.6
7.4
13.4
8.4
16.1
14.4
6.3
4.6
6.4
6.0
6.3
10.0
9.7


8.0
3.7
16.1
11.5
41.4
8.0
4.5
10.1
17.7
10.9
9.1
6.3
4.1
4.0
14.1
6-.8
16.7
13.9
1.9
4.7
15.9
6.4
23.2
18.8
3.9
1.9
4.6
3.1
3.5
8.8
8.2
LB =
U =


1.9
2.9
3.6
2.9
1.5
2.6
3.8
2.0
2.2
1.7
0.9
3.5
1.9
3.8
1.7
2.0
2.4
3.5
4.2
4.5
4.2
2.4
0.6
1.3
1.7
-2.6
2.9
3.5
4.0
3.6
2.6


4.3
1.3
4.4
3.9
28.0
3.1
1.2
5.0
8.0
6.5
9.7
1.8
2.2
1.1
8.4
3.3
7.0
4.0
0.5
1.0
3.8
2.7
40.5
14.4
2.3
0.7
1.2
0.9
0.9
2.4
3.2


LB
G
LB
LB
LB
LB
LB
F
G
LB
LB
LB
LB
LB


G = Gradient Case
F = Frontal Passage


Lake Breeze Day
Unstable Case




TABLE IV
AUGUST 1957


10-2 x


T
max
(~F)


T
lake
(OF)


U
(Kt)


U2
C T
p


10-2 x
AT
T


U2
C AT
p


Day


Type


- -- - - -... -- cl - - -


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


88
91
92
80
73
80
84
86
91
88
91
78
77
86
87
78
79
79
80
82
82
79
85
70
73
83
71
67
80
76
71


72
74
75
74
74
73
73
72
72
72
72
72
73
73
73
72
72
72
72
72
72
71
71
71
71
70
70
70
70
70
69


5.6
10.0
1L.4
10.9
10.1
8.6
8.9
13.0
6.6
4.9
13.3
11.1
9.0
8.3
10.3
5.4
9.6
7.0
8.0
9.3
14.0
13.0
10.9
9.0
11.4
7- 3
7.3
4.1
6.6


0.3
8.7
11.2
10.5
10- -
9.0
6.5
6.9
14,.6
3.8
2.1
15.7
10.9
7.1
6.0
9.4
2.6
8.2
4.3
5.6
7.6
17.4
14.8
10.6
7.1
11.7
4.7
1.5
3.9
LB =
U =


2.9
3.1
3.1
1.1
1.3
2.0
2.6
3.5
2.9
3.5
1.1
0.7
2.4
2.6
1.1
1.3
1.3
1.5
1.9
1.9
1.5
2.6
0.4
2.4
0.2
1.9
1.1
0.4


0.9
2.8
3.7
9.5
6.9
3.2
2.7
4.2
1.3
0.6
14.2
14.8
3.0
2.3
8.5
2.0
6.3
2.9
3.0
4.1
11.8
5.7
28.6
3.0
57.4
2.5
1.3
10.5


LB
LB
U
U
LB
LB
F
LB
LB
G
LB
U
U
F
LB
G


G = Gradient Case
F = Frontal Passage


Lake Breeze Day
Unstable Case




TABLE    V
MAY 1958


10-2 x


T
max
(~F)


T
lake
(OF)


U
(Kt)


u2
C T
P


10-2 x
AT
T


u2
C AT
P


Day


Type


- --- -- - -- -- --


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


72
161
76
54
58
58
66
67
59
81
84
72
76
81
83
80
85
79
70
69
72
68
65
72
71
68
81
66
74
83
81


49
49
50
50
49
49
48
49
50
50
51
51
53
54
53
52
54
55
58
59
59
59
58
58
59
59
59
60
60
60
60


19.1
12.6
16.3
18.7
23.0
14.3
10.9
13.4
15.0
12.9
12.4
0.7
15.0
11.4
5.0
6.4
19.4
17.4
25.9
10.0
12.0
4.4
14.4
13.9
14.4
12.6
14.0
12.7


32.7
32- 7
14.2
24.7
32.2
48.7
18.5
10.8
16.5
19.8
14.6
13.8
0.0
19.8
11.4
2.2
3.6
33.3
27.3
6.0
9.0
13.0
18.6
17.1
18.8
14.2
17.2
14.2
LB =
U =


4.3
4.8
0.8
1.7
1.7
3.4
3.4
1.7
5.7
6.1
4.0
4.3
5.0
5.5
5.2
5.7
4.4
2.3
1.9
2.6
1.7
2.3
4.1
1.1
2.6
4.2
3.9


77.5
- r
2. 9
2 0 9
32.0
18.5
28.0
5.4
3.1
9.5
3.5
2.4
3.5
0.0
4.0
2.1
0.4
0.6
7.5
12.0
3.2
3.4
7.6
8.2
4.2
16.6
5.4
4.1
3.7


G
U
G
F
F
LB
U
LB
LB
G
G


G


G  = Gradient Case
F  = Frontal Passage


Lake Breeze Day
Unstable Case




TABLE   VI_
JUNE 1958


T
max
(~F)


Tlake
(O~F)


U
(Kt)


U2
C T
p


10-2 x
AT
T


10-2 x
u2
C AT
p


Day


Type


- --- - -- --- - ------ --- --


1
2
3
4
5
6
7, 8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30


71
67
73
85
78
70
78
78
68
79
71
74
77
70
69
74
76
73
77
77
71
78
72
72
70
73
79
82
84
89


60
61
61
60
60
61
61
62
63
63
63
63
64
64
64
64
64
63
64
64
65
65
65
66
66
65
65
65
64
65


11.0
14.3
17. —.0
4.0
16.1. 3.4
9.3
11.0
8.4
9.1
5.9
6.7
14.3
5.3
8.1
17.0
8.3
8.4
12.6
9.1
5.7
4.4
3.7
7 7
11.4
22.4
10.4
7.9
17.7
10.7


10.9
18.5
2.6
1.4
23.0
1.0
7.7
10.7
6.4
7.3
3.1
4.0
18.2
2.5
5.9
25.8
6.1
6.3
14.1
7.5
2.9
1.7
1.2
5.3
11.7
45.0
9.6
5.5
27.5
10.0


2.0
1.2
0.4
4.7
3.3
1.7
3.2
3.0
1.0.
3.2
1.5
2.1
2.4
1.1
1.0
1.9
2.3
1.9
2.4
2.4
1.1
2.4
1.3
1.1
0.7
1.5
2.6
3.1
3.6
4.3


5.3
16.4
11.4
0.3
6.9
0.6
2.4
3.6
6.7
2.3
2.1
2.0.
7.5
2.3
6.2
13.7
2.7
3.3
5.9
3.0
2.6
0.7
0.9
4.8
15.7
30.2
3.7
1.8
7.5
2.3


G
LB
LB
U
LB
G
G
U
LB
LB
F
LB
LB
LB
U


G = Gradient Case
F = Frontal Passage


LB =
U =


Lake Breeze Day
Unstable Case




TABLE VII
JULY 1958


10-2 x


T
max
(~F)


T
lake
(~F)


U
(Kt)


u2
C T
P


10-2 x
AT
T


U2
C AT
P


Day


Type


-- ---— - -


1
IL
2
3
4
5
6
7
8
9
10
11L
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
3 0
31


88
92
72
85
89
85
81
78
84
88
81
83
84
80
87
79
78
78
79
75
82
80
85
89
84
88
88
80
84
80
69


65
67
68
68
69
69
69
69
69
70
71
71
71
71
73
73
73
73
72
72
71
70
69
69
70
70
70
71
73
73
73


14.7
10.4
14.4
5.3
12.4
2.7
0.6
6.4
4.7
15.1
3.7
3.6
13.3
12.4
13.9
15.4
4.3
6.7
15.9
13.6
11.3
1.7
5.3
5.3
9.0
5.3
11.9
13.0
13.9
5.9


19.0
9.5
18.6
2.4
13.5
0.6
0.4
3.5
1.9
20.1
1.2
1.1
15.8
13.2
17.1
20.9
1.6
3.9
22.5
16.5
11.2
0.3
2.4
2.4
7.0
2.4
12.3
15.0
17.2
3.0
LB =
U =


4.2
4.5
0.8
3.1
3.6
2.9
2.2
1.7
2.8
3.3
1.9
2.2
2.4
1.7
2.6
1.1
0.9
0.9
1.3
0.6
2.2
1.9
2.9
3.6
2.6
3.3
3.3
1.7
2.0
1.3


4.5
2.1
24.9
0.8
3.7
0.2
0.1
2.1
0.7
6.1
0.6
0.5
6.6
7.9
6.6
19.6
1.7
4.2
17.3
28.8
5.4
0.1
0.8
0.7
2.7
0.7
3.7
9.0
8.5
2.3


U
F
LB
LB
LB
LB
G
LB
G
G
LB
LB
LB
G
LB


G = Gradient Case
F = Frontal Passage


Lake Breeze Day
Unstable Case




TABLE VIII
AUGUST 1958


10-2 x


T
max
(~F)


T
lake
(~F)


U
(Kt)


u2
C T
p


10-2 x
AT
T


u2
C AT
p


Day


Type


- --


1
2
3
4
5
6
7
8
9
10.11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


82
85
93
87
87
88
85
81
86
89
88
89
83
87
80
77
82
71
79
81
76
75
78
73
69
75
80
83
87
91
79


72
71
72
72
72
72
72
72
73
73
73
73
74
74
74
74
73
72
71
70
71
71
70
70
70
70
69
69
69
69
70


6.9
4.6
7.7
4.9
15.0
10.1
8.4
9.0
7.1
10.0
5.6
7.9
6.6
9.1
3.1
6.7
8.4
8.6
6.6
8.1
8.6
7.0
9.3
4.9
9.4
11.4
10.9
11.0
22.9


4.1
1.8
5.3
2.1
19.6
0.9
6.2
7.1
4.5
8.7
2.7
5.4
3.8
7.3
0.9
4.0
6.2
6.5
3.8
5. 9
6.6
4.3
7.7
7- 7
2.1
7.8
11.5
10.3
10.5
46.3
LB =
U =


1.9
2.6
4.1
2.6
2.7
0.3
2.4
1.7
2.4
2.9
2.7
2.8
1.7
2.4
1.1
0.6
1.6
1- r
1.5
2.0
0.9
0.7
1.5
0.6
1.0
2.0
2.6
3.3
4.0
1.7


2.2
0.7
1.3
0.8
7.2
3.0
2.6
4.3
1.9
3.0
1.0
1.9
2.3
3.1
0.8
6.9
3.8
4.4
1.9
6.3
8.9
2.9
13.4
2.2
3.9
4.4
3.1
2.6
27.7


G
G
LB
LB
F
F
U
U
G
U
LB
LB
G
G
LB
G
LB
U
U
LB


G = Gradient Case
F = Frontal Passage


Lake Breeze Day
Unstable Case




TABLE IX
MAY 1959


10-2 x


T
max
(~F)


T
lake
(~F)


U
(Kt)


U2
C T
p


10-2
AT
T


U2
C AT
p


Day


Type


. ,_ -- -. le I-.. -- - —  c


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


61
82
79
77
84
88
71
62
67
79
72
76
72
50
50
58
67
73
84
84
81
78
59
72
73
81
85
86
87
77
85


50
50
51
52
52
53
54
54
56
57
57
57
57
57
57
56
56
56
57
57
56
56
57
59
58
59
60
60
61
61
62


11.0
12.4
15.1
12.4
10.9
9.7
14.3
9.7
17.7
19.4
12.7
14.6
15.6
14.4
12.3
13.6
16.4
7.1
11.9
11.7
12.7
6.9
11.3
11.1
15.9
6.9
12.0
10.9
9.6


11.1
13-.5
20.2
13.6
10.4
8.2
18.4
8.6
28.4
33.3
14.5
19.0
22.6
19.1
13.7
16.6
23.6
4.4
12.5
11.5
14.8
4.3
1-1.4
10.9
22.2
4.2
12.6
10.6
8.1
LB =
U =


2.1
5.9
5.2
4.7
5.9
6.4
3.2
1.5
2. 1
4.1
2.8
3.6
2.8
0.4
2.1
3.2
5.0
5.0
4.6
4.1
0.4
2.4
2;.8
4.1
4.6
4.7
4.7
3.0
4.2


5.3
2.3
3.9
2.9
1.8
1.3
5.8
5.7
13.6
8.2
5.2
5.3
8.0
49.9
6.6
5.2
4.7
0.9
2.7
3.0
38.9
1.8
4.1
2.7
4.8
0.9
2.7
3.5
1.9


LB
G
G
G
G
U
F
LB
G
F
LB
G


G = Gradient Case
F = Frontal Passage


Lake Breeze Day
Unstable Case




TABLE X::
JUNE 1959


T
max
(~F)


T
lake
(~F)


U
(Kt)


U2
C T
P


10-2 X
AT
T


10-2 X
U2
C AT
P


Day


Type


- e -- --


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30


75
71
82
86
86
82
88
92
93
90
85
88
67
72
72
74
73
72
81
84
86
69
73
75
90
81
91
91
93
79


63
63
64
63
63
64
65
66
68
66
67
71
69
68
68
67
66
66
65
65
66
66
67
67
68
67
67
67
67
68


15.0
11.9
6.6
7.1
6.7
5.1
8.3
11.6
10.3
9.3
10.0
15.9
12.3
5.9
16.9
13 -4
10.4
11.6
10.6
9.7
8.7
7.3
10.6
9.0
9.1
12.4
16.1
9.3
9.4


20.0
12.6
3.9
4.5
3.8
2.3
6.1
11.7
9.1
7.5
8.6
22.1
13.4
3.0
25.5
16.1
9.9
12.0
10.0
8.2
6.9
4.9
10.2
6.9
7.4
13.4
22.5
7.5
7.7


2.3
1.5
3.3
4.2
4.2
3.3
4.2
4.7
4.5
4.4
3.3
3.1
0.7
0.7
1.3
1.3
1.1
3.0
3.5
3.7
0.6
1.1
1.5
4.0
2.6
4.3
4.3
4.7
2.0


8.8
8.5
1.2
1.1
0.9
0.7
1.4
2.5
2.0
1.7
2.6
7.2
18.0
4.1
19.4
12.2
8.8
4.0
2.9
2.3
11.9
4.4
6.9
1.7
2.8
3.1
5.2
1.6
3.8


LB
LB
LB
G
G
LB
LB
G
LB
U
G
U
G
LB
G
F


G  = Gradient Case
F =   Frontal Passage


LB =
U =


Lake Breeze Day
Unstable Case




TABLE I XI'
JULY 1959


10-2 x


T
max
(~F)


T
lake
(~F)


U
(Kt)


U2
C T
p


10-2 x
AT
T


U2
C AT
P


Day


Type


- --- - -- ----- I --- L --- - - -


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31


88
82
86
86
88
80
85
89
85
87
81
81
84
86
86
90
87
80
87
80
87
90.
80
85
76
84
86
89
86
92
86


68
70
69
70
70
71
71
72
72
73
72
72
71
72
72
73
74
74
75
74
75
75
75
76
76
76
75
75
75
76
76


11.0
7.1
7.3
14.6
11.1
13.0
5.9
13.4
12.7
12.9
7.3
9.4
8.3
10.9
14.6
9.7
7.0
9.1
6.9
7.0
7.6
7.7
12.7
12.1
5.7
5.7
8.7
11.0
10.9
10.4


10.5
4.5
4.7
18.7
10.7
14.9
3.1
15.6
14.1
14.5
4.7
7.8
6.0
10.4
18.7
8.2
4.3
7.3
4.2
4.3
5.0
5.1
14.3
12.8
2.8
2.8
6.6
10.6
10.3
9.4


3.7
2.2
3.1
2.9
3.3
1.7
2.6
3.1
2.4
2.6
1.7
1.7
2.4
2.6
2.6
3.1
2.4
1.1
2.2
1.1
2.2
2. 7
0.9
1.7
1.5
2.0
2.6
2.0
2.9
1.8


2.9
2.0
1.5
6.4
3.3
9.0
1.2
5.1
5.9
5.7
2.8
4.7
2.5
4.0
7.3
2.6
1.8
6.6
1.9
3.9
2.3
1.9
15.3
7.8
2.0
1.4
2.6
5.3
3.5
5.1


G
LB
LB
G
G
U
G
LB
LB
LB
LB
LB
LB
LB


G
F
M


Gradient Case
Frontal Passage
Missing Data


LB = Lake Breeze Day
U = Unstable Case




TABLE XII


AUGUST 1959


10-2 x


T
max
(OF)


T
lake
(OF)


U
(Kt)


U2
C T
P


10-2
AT
T


x


U2
C AT
P


Day


Type


- - --


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
G
F
M


80
80
76
82
88
88
76
81
74
80
84
88
92
92
89
85
83
86
88
92
92
94
92
93
95
92
88
88
90
88
81


76
76
75
74
74
74
75
73
73
72
72
72
73
73
73
74
74
74
75
76
76
76
76
76
79
79
79
79
79
79
79


12.6
10.3
9.9
9.1
7.1
6.4
13.3
13.4
11.9
11.0
7.4
14.1
7.0
13.0
14.4
12.4
13.7
3.9
8.4
11.4
12.1
8.6
9.1
6.3
8.1
12.4
9.1
9.7
9.9
4.1
8.7


14.0
9.4
8.7
7.3
4.4
3.6
15.8
15.8
12.7
10.7
4.8
17.3
4.2
14.6
18.0
13.5
16.5
1.3
6.1
11.2
12.7
6.4
7.1
3.4
5.6
13.3
7.2
8.2
8.5
1.5
6.7
LB =
U =


0.7
0.7
0.2
1.5
2.6
2.6
0.2
1.5
0.2
1.5
2.2
2.9
1.6
1.6
2.9
2.0
1.7
2.2
2.4
2.9
2.9
3.3
2.9
3.1
2.9
2.3
1.6
1.6
2.0
1.6
0.4


19.1
12.8
43.4
5.0
1.7
1.4
78.2
10.8
62.6
7.3
2.2
5.9
2.6
9.0
6.2
6.7
9.9
0.6
2.6
3.9
4.4
2.0
2.5
1.1
2.0
5.7
4.4
5.0
4.3
0.9
18.2


LB
G
M
M
M
M
M
M
M
M
M
M
N
N
N
N
N
N
N
N
N
N
N
N
N
m
m
m
m
m
m
m


Gradient Case
Frontal Passage
Missing Data


Lake Breeze Day
Unstable Case




APPENDIX II
A SUMMARY OF COMPUTATIONS OF THE
DIMENSIONLESS VALUES FOR EACH UNSTABLE CASE








TABLE I


T     T                         -      U   U
max   lake    U    10  AT    10 2.
(~F)   (~F)  (Kt)        T         p T    p
14 June 1959    72      68    12.3   0.7       13.4      18.0
15 June 1958    69     64      8.1   1.0        5.9       6.2
23 Aug  1957    85     71     13.0   2.6       14.8       5.7
28 Aug  1958    83     69     11.4   2.6       11.5       4.4
7 Aug  1957    84     73      8.6   2.0        6.5       3.2
29 Aug  1958    87     69     10.9   3.3       10.3       3.1
21 June 1957    88     68     11.4   3.6       11.4       3.1
10 Aug  1958    89     73     10.0   2.9        8.7       3.0 -26 Aug  1957    83     70      9.0   2.4        7.1       3.0
3 May  1958    76      50    12.6   4.8       14.2       2.9
20 June 1959    84     65     10.6   3.5       10.0       2.9
11 July 1959    81      72     7.3   1.7        4.7       2.8
21 May  1959    81      56    11.9   4.6       12.5       2.7
8 Aug  1957    86      72     8.9   2.6        6.9       2.7
30 June 1958    89     65     10.7   4.3       10.0       2.3
10 June 1958    79     63      9.1   3.2        7.3       2.3
15 May  1958    83     53     11.4   5.5       11.4       2.1
2 July 1958    92     67     10.4   4.5        9.5       2.1
12 Aug  1958    89     73      7.9   2.8        5.4       1.9
9 Aug  1958    86      73     7.1   2.4        4.5       1.9


A listing of all unstable parameter cases.