Ocean 620: Introduction to Physical Oceanography
Niklas Schneider (POST 413C, x68383)
Eric Firing (MSB 416, x67594)
Pierre Flament (MSB 503, x66663)
Mark Merrifield (MSB 316, x66161)
This class is co-taught by various faculty. The primary web page
for the class can be found here.
Topics
1. Introduction and overview: what PO is; how the ocean works; the
classification of motions.
2. Introduction to (or review of) coordinate systems and vectors;
vector algebra: vector and scalar products; vector calculus: gradient,
divergence, and curl.
3. Description of fluid flow: Eulerian and Lagrangian descriptions;
streamlines and trajectories; streamfunction.
4. Intro to fluid dynamics: bydrostatic balance; conservation of mass
(continuity equation).
5. Review of elementary mechanics: Newton's laws; law of gravitation
kinetic and potential energy; simple harmonic oscillator; coupled
oscillators.
6. Momentum balance for a fluid; application to long gravity waves.
7. The (primary) ultimate energy source: radiation balance; air-sea
fluxes; greenhouse effect.
8. The physics of non-radiative fluxes: advection; turbulence; Reynolds
decomposition.
9. The result of fiuxes: general distribution of heat and salt in the
ocean; thermoclines; water masses and types.
10. Winds and upper-ocean currents.
11. Fluid dynamics in a rotating system: centrifugal and Coriolis forces.
12. Geostrophic balance: theory.
13. Geostrophic calculations: practice.
14. Ekman layers.
15. Vorticity: introduction.
16. Ekman convergence and divergence: the Sverdrup balance.
17. Potential vorticity and western boundary currents.
18. Observed WBCs compared to Sverdrup theory: recirculations rings
and eddies.
19. Water mass formation: North Atlantic Deep Water and Antarctic
Bottom Water.
20. Water mass formation: intermediate waters convergence zones.
21. Fine structure and turbulence.
22. Deep circulation: theory; Stommel and Arons model; recent
developments.
23.Deep circulation: observations.
24. Surface waves: classifications and characteristics; idealized waves;
dispersion relation; refraction and dispersion.
25. Surface waves: spectra; generation nonlinear interaction dissipation.
26. Internal waves.
27. Kelvin waves.
28. Rossby waves.
29. Tides: theory and observations.
30. Equatorial circulation: observations and theory.
31. El Nino and the Southern Oscillation (ENSO).
32. Coastal oceanography.
33. Scale analysis; review of the main dynamic balances.
These topics will be covered roughly in the order listed above, with
occasional shifts to accomodate the instructors' travel schedules. Topics
do not always correspond to complete single lectures.
Examinations
There will be 2 midterms and a final examination. All will be take-home.
After each midterm, you will be strongly encouraged to discuss the
results, and your progress in the course, with the instructors. In
addition to the written final, there will be an oral component to be
scheduled during finals week.
Readings and presentations
Reading assignments from the text and other sources will be given on
occasion, but it is also your responsibility to read as needed; in many
cases you will be the best judge of what you need to read to master
the material.
We will assign short student presentations on selected readings.
The text covers only a fraction-perhaps even less than half-of the
subject matter of this course. Therefore you will have rely on notes,
both yours and ours, to supplement the texts.
Previously we used Introductory Dynamical Oceanography, by Pond and
Pickard, as a required text. It was never very well liked, but some
students have reported they found it help- ful. So, try borrowing a copy
of IDO and see if it helps you. Another book that you may find helpful as
a ref- erence is Principlcs of Ocean Physics by John Apel. It is quite
comprehensive in its coverage of dynamical oceanography, acoustics,
and op- tics. Because of its range of coverage, l suspect it might be
a worthwhile purchase for some non-PO students as well as PO students,
particularly bi- ologists who must deal with optics and/or acous- tics.
Atmosphere-Ocean Dynamics by Adrian Gill is an excellent text and
reference. Although as a whole it is too advanced to he used as a primary
text for this course, parts will probably he helpful to many students
now, and it will be invaluable to those who continue their studies of
physical oceanography or meteorology.
Last, there is a rather old book by John Knauss, Iniroduciory Physical
Oceanography, that you may find useful if you are struggling with some
of the PO basics. It is clear and easy to read, but its coverage is
quite limited and dated.
Notes
For the majority of the lectures, we will provide ready-made notes. These
will vary from simple outlines to something resembling excerpts from a
(nonexistent) text. Check with one of last year's students to see what
last year's notes looked like and included. This year's will be similar,
but as always we hope to fill in some gaps and make some improvements. The
lectures will not correspond perfectly to the notes; the notes are
important supplements. Read them! If you don't understand something,
discuss it with other students. If you still don't understand, ask an
instructor about it.
Problems and exercises
We will frequently give out study questions and problems to he solved.
Try to work the simpler exercises by yourself, but if you get stuck,
or for the harder questions, you are encouraged to work in groups;
just he sure that you thoroughly understand anything you hand in. The
purpose of these exercises is to lielp you understand the subject
matter. They will be reviewed but not graded. They may, however, be the
most important part of the course-the most effective tool for learning
about how the ocean works.
Lectures
Please try to answer our questions, and please ask us questions if there
is something we are saying that you don't understand. (We may occasion-
ally have to defer long explanations or digressions in the interest of
finishing on time.)
Computers
We encourage you to become proficient in using computers for writing,
calculating, and plotting. You will have to learn sooner or later,
so save yourself some trouble and make it sooner. We highly recommend
a program called Matlab for most scientific calculation and plotting. It
is available on many PCs and on the SOEST Sun network.
For producing documents, we use the LATEX formatting system, which is
also available on the Sun network. LATEX is powerful (especially for
equations), portable, widely used (for example, for making theses and
camera-ready journal articles) and free but it is not always easy to
use, and it takes a bit of time to learn.
Ask a student who uses Matlab and LATEX to introduce them to you.
Mathematics
An important part of the language of physical oceanography is vector
calculus, with which some of you may not yet be familiar. We cannot pro-
vide a full course in vector calculus, and we will not require you to
learn it well enough to solve complex problems. But we will introduce
the basic concepts and symbols, and we will expect you to learn them
well enough to understand their physical meaning and perform some simple
cal culations.
Goals
By the end of this course, we expect all students to be familiar with
the main features of the world ocean circulation and hydrography, with
the main classes of ocean waves, with other important processes such
as mixing, and with the dynamic balances that govern these phenomena
and processes. We recognize that we will be covering a broad area and
introducing many new and sometimes unintuitive concepts. Just do your
best, and rest assured that your exposure to these concepts, and the
effort you put into understanding them, will be worthwhile so long as
you pursue your interest in oceanography.
In addition to learning facts and concepts, you should gain some skills
such as the following:
* perform simple scale analysis
* calculate Ekman transport and estimate velocity in an Ekman layer
* interpret a CTD section in terms of TS relations
* calculate geostrophic currents
* interpret a current meter record
* interpret a sea level record
* predict wave arrival times from a storm
* read and understand a JPO paper
In other words the goal is not just to know some things, but to be able
to do something with what you know.