GFD III , Winter 2019

Professors Jen MacKinnon and Bill Young

T/Th 9:30-10:50, Nierenberg Hall 101

 

Course Overview

The goal of SIO212C --- a third course on geophysical fluid dynamics --- is to provide physical oceanography students with the background required to work at the frontier of research on unbalanced processes with an emphasis on upper-ocean and mixed layer dynamics. Some of these were once balanced but have ceased to be so (e.g. frontal instabilities), some were never balanced (e.g. internal waves), and some are nonlinear interactions between the two. These topics are of increasing community interest and are central to many ongoing SIO research projects but are not accommodated in parts I and II of the geophysical fluid dynamics sequence SIO 212. Most of these topics are not covered in any pedagogical textbooks, and students (and PIs!) are left to pick up what they can from individual research papers. Here we hope to put together a systematic treatment, an broad intellectual framework in which to understand many of these hot topic issues. This material is intended primarily for second year and above students who have at least taken the first year Fluids and GFD courses. Other interested scientists at any level are quite welcome to sit in and join the discussion.

Each class will involve a combination of lectures and student led discussion of relevant papers that connect lecture material to areas of active research. The paper associated with each lecture is listed below. Additional reference material of possible interest is listed further down.

Schedule

  • 1/8: NO CLASS

  • 1/10: Overview of submesoscale processes and dynamics, governing equations, parameter space for the quarter, plan for the class

  • 1/15: Review of basic internal wave equations, dynamics [Paper of the day: tbd…]

  • 1/17: More internal wave basics, propagation, WKB, ray tracing.

  • 1/22: Internal tides: generation, modes, global patterns, power.

  • 1/24, ** 2:30-4pm: Near-inertial waves. Slab model wind generation. Interaction with ambient vorticity field. Global maps, power.

  • 1/29: Wave / mean flow interaction

  • 1/31: The kinematics of passive scalars and passive vectors. Stirring, mixing, gradient amplification and enhanced dispersion.

  • 2/5: The internal wave continuum. Garrett-Munk. Triad interactions and energy transfer. Mechanics and patterns of wave breaking. Global patterns and budgets.

  • 2/7: Continuum discussion continued. Some GM+wave-wave interaction +finescale parameterization slides

  • 2/12: Continuum part 3, and a few lee waves.

  • 2/14: Fronts of the world, and QG basics. Lecture notes (click) and Slides

  • 2/19: Quasigeostrophic frontogenesis. Semigeostrophic frontogenesis: balanced frontogenesis --- the Hoskins \& Bretherton model and unbalanced frontogenesis --- Blumen's model.

  • 2/21: Frontogenesis and instabilities continued

  • 2/26: Frontogenesis and instabilities continued

  • 2/28: Frontogenesis and instabilities continued

  • 3/5: Frontogenesis and instabilities continued

  • 3/7: Back to wave / mean flow interactions, the complicated version, part I

  • 3/12: Back to wave / mean flow interactions, the complicated version, part II

  • 3/14: Student presentations

Office hours:  contact either professor individually to figure out a good time to stop by.

 

HOMEWORK

The classes will involve a combination of formal lectures on the underlying theoretical framework coupled with class discussion and presentation of research papers --- both classic and cutting edge. There will be a few formal homeworks, as we think there are some things you will (later) appreciate having had to derive yourself, and thus understand thoroughly. However befitting a senior graduate student class the majority of the work expected will be a combination of reading assigned cutting edge papers (and coming to class prepared to discuss them), and a modest size term project of flexible nature. There are no written exams.

Homework #1 (click on it), due Thursday Jan 17th in class.

Homework #2, due 14 Feb in class

Homework #2.5, due 21 Feb in class. Associated matlab file of data here

Homework #3, due tbd

Homework #n, student presentations and short write up.

 

GRADING

Grades will be based on a combination of written assignments and class participation.

Additional Reference material (click on each one to go to the paper). As a disclaimer, these are not meant be comprehensive or particularly representative, but are some of the papers we talked about in class.

Internal tides: generation and propagation

Near-inertial internal waves: generation and propagation

The role of surface waves

Wave-wave interactions, triad theory, G-M and the internal wave continuum

Jody Klymak’s matlab representation of the G-M spectrum is here

Finescale parameterizations of mixing as applied to data:

Parameterizations for models

Frontogenesis

Internal wave mesoscale interaction