AIMS AND CONTENT

LEARNING OUTCOMES

To provide the basics of geophysical fluid dynamics: ruling equations and peculiar dynamical phenomena induced by apparent forces, i.e., centrifugal and Coriolis forces.

AIMS AND LEARNING OUTCOMES

The student is invited to participate assiduously to the proposed educational activities consisting of lectures and exercises,
with the ultimate goal of:

know the basics of geophysical fluid dynamics;

understand the basic physical mechanisms of fluid motion in the atmosphere and sea;

identify phenomena from current life ruled  by fluid dynamic mechanisms analyzed in the course;

estimate the degrees of freedom needed to describe a turbulent system;

evaluate the situations in which to use RANS-type rather than LES-type approaches, also depending on the available computing power;

evaluate the merits and limitations of CFD modeling to study the dynamics of the atmosphere and / or sea systems;

critically discuss the problems of geophysical fluid dynamics using the appropriate vocabulary.

TEACHING METHODS

The course includes lectures in the classroom. These are divided into lectures dedicated to the more theoretical aspects of geophysical fluid dynamics alternated with exercises aimed at fixing theoretical concepts by discussing practical examples, also borrowed from everyday life.
Learning of communication skills will be encouraged with the proposal to hold a seminar (20 minutes) on an application of geophysical fluid dynamics at sea or in the atmosphere which will then be evaluated during the examination.

SYLLABUS/CONTENT

The course program includes the presentation and discussion of the following topics:

- Navier-Stokes equations in an inertial reference system (8 hours)
* quick reminder in the incompressible case
* Boussinesq approximation and convection
* energy balance

- Navier-Stokes equations in a rotating reference system (8 hours)
 * f plane model
 * beta-plane model
 * geostrophic model
 * Ekman layer on the free surface (ocean)
 * Ekman layer on the rigid surface (atmosphere)
 * ground circulation (friction effect and convergence phenomena)

- Atmospheric stability (6 hours)
 * generalities
 * dry adiabatic lapse-rate and moist adiabatic lapse-rate
 * static stability and potential temperature
 * stable, unstable and neutral atmosphere (mechanisms and examples)

- Circulation on a local scale (6 hours):
* role of friction on the motion near the ground
* role of the curvature of the isobars near the ground
* thermal circulation
* sea and mountain breezes
* the monsoons

- Turbulence (10 hours)
* generalities on phenomenology as the Reynolds number grows
* homogeneous and isotropic stationary turbulence
* the law of 5/3 of the energy spectrum
* on the impossibility of describing in full the degrees of freedom of the system in the limit of large Reynolds
* from the DNS scheme to the RANS and LES ones

- RANS and LES type equations (12 hours)
 * definition of filtered field
 * equations for the filtered field
 * the problem of closure
 * examples of closure (the Smagorinski model and the dynamic model of Germano)
 * the meteorological model WRF operating at  DICCA for weather forecasts (with expert staff seminar)

RECOMMENDED READING/BIBLIOGRAPHY

Il materiale didattico utilizzato durante le lezioni sarà disponibile in aulaweb dell’insegnamento. Gli appunti presi durante le lezioni e il materiale in aulaweb sono sufficienti per la preparazione dell’esame, ma i libri seguenti sono suggeriti come testi di appoggio e approfondimento:

Fluid Mechanics, Pijush K. Kundu, Ira M. Cohen, David R. Dowling, Gretar Tryggvason (Elsevier, 2015, sesta edizione)

Turbulence: The Legacy of A. N. Kolmogorov, Cambridge Univ. Press, 1995.

Meteorology Today, An introduction to Weather, Climate and the Environment, C. Donald Ahrens, seventh Edition, 2003.

TEACHERS AND EXAM BOARD

Exam Board

ANDREA MAZZINO (President)

GIOVANNI BESIO

MARCELLO GATIMU MAGALDI

LESSONS

LESSONS START

https://corsi.unige.it/10720/p/studenti-orario

Class schedule

The timetable for this course is available here: Portale EasyAcademy

EXAMS

EXAM DESCRIPTION

Written exam and oral presentation in the form of seminar on a topic to be decided with the docent.

ASSESSMENT METHODS

The student must have demonstrated that he has assimilated the basics of geophysical fluid dynamics. This will include:

- the ability to discuss a geophysical fluid dynamics problem with the appropriate technical language;

- the ability to solve simple geophysical fluid dynamics problems taken from the everyday life.

Exam schedule