XMOD II Agenda

The Xiamen Spring School on Ocean Dynamics (XMOD) aims at introducing fundamental ocean dynamics, from the basics to the research frontiers, to graduate students and early-career scientists. The topics cover a wide range of oceanic phenomena and processes. It has a specific theme for every course. For each course, prestigious scientists who have made seminal contributions to the theme-related field are invited to deliver principal lectures. The school, held over one to two weeks, will consist of:

• Principal Lectures: introducing theme-related basics and research frontiers given by the principal lecturers. The lectures will be given in English.
• Contributing Talks: covering broader materials presented by guest lecturers and school participants. The talks will be in either English or Chinese.

The first XMOD (XMOD I), with the theme of Ocean Dynamics at Meso- and Submeso- Scales, was held on March 12–17, 2018 at the State Key Laboratory of Marine Environmental Science (MEL) of Xiamen University. The two principal lecturers for XMOD I were Dr. Bo Qiu (University of Hawaii at Manoa) and Dr. Patrice Klein (Ifremer / CalTech).

The second XMOD (XMOD II) will be held on May 6-10, 2019. The theme of XMOD II is Upper Ocean Dynamics. The two principal lectures are:

List of XMOD-II Lecturers

Agenda

May 6-10, 2019

 Lecture Hall A3-206, Zhou Long Quan Building, Xiamen University Xiang’an Campus

Syllabus of Dr. William D. Smyth’s Lectures: Upper ocean dynamics: diapycnal processes

Course materials: http://salty.oce.orst.edu/index.html

Lecture 1: Classical turbulence    

Why study turbulence?

• human fascination
• practical importance
• scientific challenges

Pipe flow: Dimensional analysis and the Reynolds number

Statistical properties

• stationarity
• homogeneity
• isotropy

Kolmogorov’s great idea: universal structure at high Re

The Richardson cascade, mechanism (small scales most vulnerable)

• the kinetic energy spectrum of turbulence

• the viscous dissipation rate

Dimensional analysis of the kinetic energy spectrum

• universal range, the Kolmogorov scale
• inertial range
• verification
• other spectra: dissipation, scalar variance, the Batchelor scale

Self-similarity

Eddy viscosity/diffusivity

Lecture 2: Geophysical turbulence

Geophysical influences:

• mean shear
• stratification
• rotation

Which motions are affected?

• The Ozmidov scale
• The Corrsin, scale
• The Rhines scale

Instability

• plane wave disturbances
• convective instability
• double diffusion

Lecture 3: Geophysical turbulence (continued)

Instability

• inflectional instability
• instability in stratified shear flows     

Turbulence energetics

• mass conservation
• buoyancy
• potential energy balance
• kinetic energy balance, special cases

Turbulence parameters 

• fluxes, diffusivities
• thermohaline stratification
• diffusion of buoyancy
• the turbulent Prandtl number

Measuring turbulence

• the missing mixing
• local isotropy, the Ozmidov scale, buoyancy Reynolds number
• measuring chi & epsilon
• hot spots
• mixing efficiency: Osborn and Osborn-Cox methods, resolution

Lecture 4: Upper ocean turbulence

Fluxes across the ocean surface

• solar irradiance
• air-sea fluxes

The surface microlayer 

Surface gravity waves

• wave spectra
• the Stokes drift

• plunging breakers
• spilling breakers

The surface mixed layer

• seasonal
• diurnal

Monin-Obukhov scaling

• wind-driven boundary layer

Lecture 5: Upper ocean turbulence (continued)

Monin-Obukhov scaling (continued)

• wind+buoyancy flux
• pure convection

The Ekman spiral

Parameterizations   

• algebraic
• 1-equation
• 2-equation

Equatorial mixing

• observations
• mechanics

Fractal geometry

• the fractal dimension of Gulangyu
• the curve that broke calculus

Syllabus of Dr. Baylor Fox-Kemper’s Lectures: Upper ocean mixing: horizontal processes

10 1-hour lectures + project

PART 1: Classical oceanography (lecture 1)

       Vorticity of the general circulation

Ekman & Sverdrup transport

       Gyres and ventilated themocline

       Climatological density gradients

       Western boundary currents

       Antarctic Circumpolar Current

       Mode water

PART 2: Geophysical Basin Scales (lectures 2-4)

       Introduction: Reduced equations of motion

       Boussinesq approximation

              Sound waves are filtered

              What is energy?

       Hydrostasy

              Large aspect ratio motion

       Planetary geostrophy

              Zero Rossby number

              Conservation of potential vorticity

              Gyres & ACC in planetary geostrophy

              Outcropping—the Parsons Model

              Energetics

              Horizontal divergence

       Quasigeostrophy

              Moderate Rossby number

              QGPV and SQG

              Gyres & ACC in QG

              What sets the stratification in QG?

              Energetics

              Horizontal divergence

       What about climate change?

              MOC?  Stratification trends?  Tropics? 

PART 3: Mesoscale, Submesoscale, and Beyond (lectures 5-9)    

       QG Linear instabilities

              Eady

              Others

       Non-QG Linear instabilities

              Stone

              Craik-Leibovich

              Mixed Layer Instabilities—

Convective & shear [mostly for Bill]

Symmetric

Geostrophic

Langmuir

       The Mesoscale—Linear or Nonlinear?

              Chelton & Schlax (1998) vs. Chelton et al. (2007)   

       The Nonlinear Mesoscale as Macroturbulence

             Anisotropy: neutral and dia-neutral orientation and energy

  The Gent-McWilliams and Redi/Solomon Parameterizations
            The 2D and QG cascades

  The Leith and QGLeith Parameterizations

  Rossby and Richardson Numbers from the basin to grid scale

       The Submesoscale: Ageostrophic & Weakly Stratified

              How big? Ro~1, Ri~1

              Ageostrophic effects at the submesoscale

                     Frontogenesis

                     Turbulent thermal wind

         Down-front Ekman forcing and SI parameterization

                     Mixed Layer instabilities and MLE parameterization

                     Stokes-driven Frontogenesis

Beyond The Submesoscale: Nonhydrostatic Effects

                     Langmuir turbulence

                     The rest [mostly from Bill]

PART 4: Parameterization Comparison & Effects (lecture 10)

       QGLeith parameterization

       MLE parameterization

       Langmuir parameterization

       What about climate change?

              Ocean Heat Content Anomaly

              Processes affecting sea level rise

              Hasselmann & Frankignoul

              Eddy-Surface Flux Feedbacks

              Transient climate response

              Equilibrium climate sensitivity