OCP 5253--Introduction to Geophysical Fluid Dynamics

OCP 5253--Introduction to Geophysical Fluid Dynamics Course Syllabus, Fall Semester, 2013 (revised 8/23 2013) Tentatively scheduled for Wed 11:15- 2:00 pm. Exact time will be arranged during the first meeting; Room 327 OSB Instructor: Professor Doron Nof, 419 OSB OFFICE HOURS Tu/Thu 14:00 – 15:00

Dept Ph 644-6700; Direct Ph 644-2736

Course Description: The purpose of this first-year graduate class is to introduce the student to the basic principles governing the motion of fluids on a planetary scale. The primary effects that will be discussed are the effects of rotation and stratification on fluid motions. The focus will be on motions in oceans and atmospheres (on earth and other planets). The class is usually supplemented with actual demonstrations of fluid motions, many of which fit directly over a modified overhead projector. Some examples are, Coriolis deflections, Taylor curtains, Taylor columns, Taylor-Proudman theorem, bottom Ekman Layers, Sverdrup balance, and windinduced separation and its relationship to the Parson’s model. Textbooks: The class will be based on Introduction to Geophysical Fluid Dynamics” (Second Edition) by Professor Benoit Cushman-Roisin and Jean-Marie Beckers (Academic Press 2011), with occasional supplements from Stern’s Ocean Circulation Physics, Salmon’s Lectures on Geophysical Fluid Dynamics and Pedlosky’s Geophysical Fluid Dynamics. Lecture and Course Outline: 1. Introduction a. b. c. d. e. f.

Objective Importance of geophysical fluid dynamics Scales of motion Importance of rotation Importance of stratification Important distinctions between the oceans and atmosphere

2. The Coriolis Force a. b. c. d. e.

Motivation for the choice of a rotating reference framework Rotating frame of reference Unimportance of the centrifugal force Motion of a free particle on a rotating plane Acceleration on a three-dimensional rotating earth

3. The Governing Equations

a. b. c. d. e. f.

Momentum equations Other governing equations The Boussinesq approximation Further simplifications The equations governing geophysical flows The Rossby and Ekman numbers

4. Geostrophic Flows and Vorticity Dynamics a. b. c. d.

Homogeneous geostrophic flows Homogeneous geostrophic flows over an irregular bottom (Taylor columns) Generalization to non-geostrophic flows Vorticity dynamics

5. The Ekman Layer a. b. c. d. 6.

The importance of friction The bottom Ekman layer The surface Ekman layer The Ekman layer in real geophysical flows

Geostrophic adjustment a. The simplest adjustment problem (a wall pushed sideways) b. The full adjustment problem c. The collapsing cylinder d. The collapsing wedge

7.

Large-Scale Ocean Circulation a. A simple model of mid-latitude circulation b. Sverdrup transport c. Westward intensification

8.

Layered models a. Two layers “reduced gravity” models b. Parson’s separation model c. Analogy between the Parson’s model and wind set-up in a lake d. Analogy between Parson’s model and the thermocline structure along the equatorial Pacific

There will be several homework assignments and a set of exams whose specifics will be determined in the first meeting with students input. The final grade will be determined on the basis of homework evaluation (10%) and the exam(s) grade (90%). Occasionally, the lectures

will be supplemented with various videos of relevant laboratory experiments. Students are reminded that the university has an Academic Honor Code (described in the Student Handbook).