APPH G4410 - Geophysical Fluid Dynamics
Spring 2008

Syllabus (PDF)


Class Notes (email me)


Homework Assignments

Problem Set 1

Problem Set 2

    Data file for problem 2: N_profile

    Your solution to prob. 2 should look like this: normal_modes.pdf

    Matlab code to compute exact and approximate (WKB) normal modes and equivalent phase speeds: M-files

Problem Set 3

Problem Set 4

Problem Set 5

Problem Set 6

Problem Set 7

Final Exam

   Solution (Matlab code) for  problem 3 which asks you to numerically solve the transient 'Gill' problem. (This version was written
   by Wenchang Yang, one of the students in the class. It comes with a nice GUI, and uses an implicit time-stepping algorithm to solve
   the forced shallow water equations at the equator.) If you want a more generic (and significantly faster) fortran implementation, email me.  

Matlab and fortran code

Generic wave equation solver (only requires the dispersion relation): waves_2modes.m

Raytracing: sound waves in the ocean, gravity waves approaching a beach

Geostrophic adjustment-1: geostrophic_adjustment.m (also need this: waves_2modes.m)

Script to plot the Eady solution: eady_wave.m, eady_wave.pdf

Shallow Water Equations: Fortran files

Everything as a single tar file: swe.tar

This is a fairly complete implementation of the linear shallow water equations on the beta-plane for a fluid of variable depth. The numerics, while by no means state-of-the-art, are adequate and the code is modular and easy to follow. You can use the code to study everything from geostrophic adjustment to tides. (But watch out for the bit that switches evaluation of the Coriolis term at even and odd time steps. This avoids setting up a nasty computational mode.)

To compile: type "make" (on Linux, this expects pgf77 or pgf90 to be in your path. On OS X, the makefile will work for absoft f77.)

To run: ./swe2d

See the m-files for examples of how to generate initial conditions and a bathymetry file, and how to view the output. Otherwise, feel free to ask me.

Contact Information:

Samar Khatiwala
Oceanography 204
Lamont Doherty Earth Observatory
Columbia University
Palisades, NY 10964

Email: spk@ldeo.columbia.edu
Phone: 845-365-8454
Fax: 845-365-8736


samar khatiwala