318
R. F. BOWDEN ET AL.
implies that k‘,” increases linearly with t or cr,, corresponding to a constant
diffusion vclocity. The case m = 3 corresponds to K, being proportional to
~7;’~. which is consistent with inertial subrange conditions in locally isotropic
turbulence, if u, is identified with the scale of the process.
Figure 1 shows the areas of the Irish Sea in which experiments were made.
In Fig. 2 a curve of cry2 against t is shown for one of the releases in Red Wharf
Bay in June 1969. The regression line fitted to the bilogarithmic plot corresponds to cr,’ proportional to t 2 . ’ . The value of the index varied considerably
from one release to another but the median value was approximately 2.
FIG. I . Chart of the Irish Seu showing localions of experimental areas.
Figure 3 shows the relation of cr; to t for one of the releases in Liverpool
Bay in September 1971. The scatter is somewhat accentuated in that points
for the three sampling depths are plotted on the same diagram. The line
shown is displaced but it has the slope m = 2.3, found by fitting a regression
line to the points by a least squares method.
Thc 1970 and 1971 data were all obtained and analysed in the same way
and most of the following statements refer to these data and the results
derived from them. A total of 22 releases was made in the two years. with an
average of nearly 20 crossings per release. In 10 releases the significance of
the linear regression line was below the 5 ‘4 level. Confining attention to the
R. F. BOWDEN ET AL.
implies that k‘,” increases linearly with t or cr,, corresponding to a constant
diffusion vclocity. The case m = 3 corresponds to K, being proportional to
~7;’~. which is consistent with inertial subrange conditions in locally isotropic
turbulence, if u, is identified with the scale of the process.
Figure 1 shows the areas of the Irish Sea in which experiments were made.
In Fig. 2 a curve of cry2 against t is shown for one of the releases in Red Wharf
Bay in June 1969. The regression line fitted to the bilogarithmic plot corresponds to cr,’ proportional to t 2 . ’ . The value of the index varied considerably
from one release to another but the median value was approximately 2.
FIG. I . Chart of the Irish Seu showing localions of experimental areas.
Figure 3 shows the relation of cr; to t for one of the releases in Liverpool
Bay in September 1971. The scatter is somewhat accentuated in that points
for the three sampling depths are plotted on the same diagram. The line
shown is displaced but it has the slope m = 2.3, found by fitting a regression
line to the points by a least squares method.
Thc 1970 and 1971 data were all obtained and analysed in the same way
and most of the following statements refer to these data and the results
derived from them. A total of 22 releases was made in the two years. with an
average of nearly 20 crossings per release. In 10 releases the significance of
the linear regression line was below the 5 ‘4 level. Confining attention to the