Equatorial Rossby Soliton
The following list contains the files
needed to run the equatorial Rossby soliton problem. The reference is:
John P. Boyd, Equatorial solitary
waves Part I: Rossby solitons, Journal of Physical Oceanography, v.
10, # 11, 1699-1717, 1980.
To make the executable:
-
Copy dimns.F90 and "Sflags.h" files to
the directory src, e.g. "cp dimns.F90 Sflags.h ../src11"
-
Copy the initialization source file: "cp trossby.F90 tuser.F90"
The file trossby2.F90 contains a more accurate initialization of the
equatioal Rossby wave.
-
Update the dependency list in the Makefile: "make depend".
This will run the preprocessor to create the "*.f90" files from the
"*.F90" ones.
-
Create the executable by giving the command "make shallow".
-
Move the executable shallow to the directory containing the
example problem.
-
Run the code with the command:"shallow < rossby.in". It should
not take long to run.
-
View the contours of the depth anomaly with ncargraphics. You
need to create the gmeta file with the command
"contours < zeta.com", or by running the matlab script pcont.m.
-
The grid in the computation can be drawn with the drawcoast program.
After building the executable in directory ../../plot, it can
be executed as "drawcoast < grid.com".
Boyd's asymptotic solution to the Rossby soliton problem predicts a
balance between dispersive and nonlinear effects that allows the
soliton to preserve its shape while traveling westward at a constant
phase speed. The numerical solution reproduced this behavior quite
faithfully. The discrepancies between the numerical solution and
Boyd's asymptotic solution are negligible and are due to the asymptotic
nature of Boyd's solution. In particular the initial condition is not
exact and hence a small part of the wave disperses eastward as
Kelvin waves. SEOM gives a soliton phase speed of 0.76 m/s
while the asymptotic solution predicts a value of 0.78 m/s.
Results of SEOM simulations can be examined on the
IMCS web site.
¢
Figure:
A wire mesh plot of the surface
elevation at the beginning and end of the simulation.
.
|