Laboratory Experiments in Geophysical Fluid Dynamics

 

Physics 6363

 

Lectures will be twice per week, for a total of 3 hours.

The instructor will be Dr. Iakov Afanassiev


Telephone: (709) 864-2500
Office: C-4065
Lab:1046
Email: afanai@mun.ca

http://www.physics.mun.ca/~yakov

 

 

General Description

 

 Moving fluids are a part of the natural world, and their dynamics impact the ocean and atmosphere as well as many other problems of science and engineering. Fluid processes are complex (the equations of motion are three-dimensional, unsteady and nonlinear) and the theory is sufficiently incomplete. Many natural processes occur over too large a scale in time and space (ten orders of magnitude in length-scale variations for the flows in the ocean) so that even the most advanced computer models cannot adequately describe real systems. Laboratory experiments are a great way to learn about fluids and provide an invaluable research tool to link theory and observations.

 Laboratory work involves many skills: understanding how to scale real phenomena to the laboratory, building apparatus, observing experiments, visualization, digital photography and data analysis including image analysis. The objective of this course is to give the student the theoretical basis of the laboratory experimentation in GFD through lectures as well as practical skills.� This will include the development and implementation of your own fluid dynamics experiment to study a problem that interests you, the results of which will be reported in a paper and video which you will create.

The course will consist of lectures (some with lab demonstrations) and practical work on your project of choice in the laboratory.

 

Supplementary texts

B. Cushman-Roisin. 1994. Introduction to Geophysical Fluid Dynamics. Prentice Hall, Engelwood Cliffs, 320 p.

 

S.I. Voropayev and Y. Afanasyev .1994. Vortex Structures in a Stratified Fluid. Chapman and Hall, London, 230 p.

 

Course

 

The topics of lectures are outlined below.

 

  1. Importance of GFD. Geophysical examples. Scales of motion. Importance of rotation and stratification.
  2. Introduction to experimental techniquies. Particle image velocimetry technique.
  3. Introduction to experimental techniquies. Altimetric image velocimetry technique.
  4. Effects of rotation. The Coriolis force. Taylor-Proudman theorem. The Rossby and Ekman numbers. The Ekman layer. The f-plane and b-plane. Vortices in the rotating environment. Potential vorticity. The Kelvin wave and Rossby wave. Flow over topography.
  5. Effects of stratification. Internal waves. Baroclinic instability. Double diffusion. Gravity current.

 

Lab Demos

 

There will be a few lectures with the laboratory demonstrations. These lectures will take place in the lab rather than in a regular class room.

 

Assignments

 

 There will be several assignments which involve reading an assigned research article, preparing a “digest” of the paper and presenting it in class. The assignments will be worth 30% of your final mark.

Projects

 

In the term project you will model experimentally a simplified real-world problem. The ultimate goal of your project is to produce a comprehensive report describing your project including background information, photographs/movies and references. We can suggest a project for you, or you can come up with your own. Since the project will take a substantial amount of time and effort and may require building an apparatus in advance, we suggest that you keep it in mind as we go through the material. Selection of the project should be made before the sixth week of the term so that you can begin to prepare. I would like to meet with each of you individually to discuss your interests and explore possible projects. We will then have informal follow up meetings to discuss practical aspects of your project and to make sure you have the equipment you need to get going. A 10 min presentation of your research plan will be given at the first class in week eight. In this presentation you will describe why this research topic is important, previous studies (you have to conduct literature search), what are you going to do and by what experimental means. This preliminary presentation will worth 10 % of your final mark. You will start working on your project in the laboratory with the help of the instructor by the ninth week of the term. You should give the final 20 min presentation in class (last week of classes). This presentation should follow the form of a research talk and will be worth 15 % of your final mark. You should also submit the research paper at this time. The paper should follow a format required for research papers in one of the journal in the field (JPO, JFM, PhysFluids). The paper is the most important component of this course and will be worth 40 % of your final mark. The last part of the final project report includes the project video (Youtube style) where you present your project for a wider audience in order to promote your work. The video will be worth 15% of your mark.

 

The possible ideas for the projects are given below.

Eddies, zonal jets and Rossby waves on the polar beta-plane

Inertial waves on the f-plane

Baroclinic instability, frontal instability

Vortex dipoles in rotating/stratified fluid

Flow over topography in a rotating fluid (f-plane, beta-plane)

Tornadoes

 

Marking

 

Assignments  20 %

Preliminary presentation 10 %

Project video 15 %

Project paper 40%

Final presentation 15 %