81828 - Basics of Physic of the Atmosphere and Meteorology

Academic Year 2021/2022

  • Moduli: Federico Porcù (Modulo 1) Laura Sandra Leo (Modulo 2)
  • Teaching Mode: Traditional lectures (Modulo 1) Traditional lectures (Modulo 2)
  • Campus: Bologna
  • Corso: First cycle degree programme (L) in Physics (cod. 9244)

Learning outcomes

At the end of the course the student has acquired the basic knowledge of the long term mean properties of the atmosphere and of the basic equations of fluid dynamics. The laws of thermodynamics are applied to a gaseous fluid with phase changes. The equations of atmospheric motion are introduced with applications to some aspects of synoptic meteorology of mid-latitude weather systems with the aid of meteorological chart and satellite imagery. The fundamental radiative processes are introduced to interpret observations from space and to justify the simple planetary energy budget that introduces to the greenhouse effect

Course contents

Module 1

Spatial and temporal scales. Basic concepts of atmospheric fluid dynamics (Knudsen Number, air parcel, eulerian and lagrangian views, total derivative).

Navier-Stokes equation, viscous and inertial forces. Qualitative sketch on transport phenomena. Reynolds number and regimes, linearity and non-linearity, examples. Mass conservation equation with eulerian and lagrangian approach.

Equation of motion on a rotating system: scale analysis.

Simple equilibrium configurations: inertial motion, geostrophic motion (with and without friction), example of finite difference method.

Gradient wind, role of pressure gradient in the evolution of baric systems. Cyclostrophic wind, Rossby Number.

Isobaric and isentropic coordinates, thermal wind. Barotropicity and baroclinicity. Horizontal divergence and vertical motion

(application to global circulation).

Fronts: pressure, temperature and winds across frontal surfaces. Sketch of extra-tropical cyclone structure. Examples on meteorological charts.

Fronts and cyclones in meteorological satellite imagery: conveyor belt, dry intrusion, warm sector, gust fronts, squall lines.

Basic introduction to weather forecast: nowcasting, NWP, data assimilation, ensamble forecast. Available global products (ERA, NCEP, Globo), and regional (bolam, moloch).

Module 2

Introduction to atmospheric physics and meteorology. Observational network (in situ and remote sensing). Temporal and spatial mean atmospheric variables. Vertical profile of chemical species and physical quantities.

Equation of state of dry air and adiabatic processes; thermodynamic properties of water. Potential temperature and equivalent potential temperature, moist adiabats, stability and CAPE. Thermodynamic diagrams.  

Introduction to radiative processes: emission, diffusion, absorption.

Theory of the general circulation of the atmosphere. Simple energy balance models. The Earth climate systems: definitions and observations.

Readings/Bibliography

Lecture notes of both modules are available online, with extensive bibliography.

Atmospheric Science, An introductory survey. John M. Wallace e Peter V. Hobbs, Second Edition, Academic Press 2006.

Holton, J.R., An Introduction to Dynamic Meteorology (4th Ed.) Elsevier-Academic Press, New York (2004), pp 535.

Visconti, Guido. Fundamentals of Physics and Chemistry of the Atmosphere. Berlin: Springer, 2001.https://www.springer.com/gp/book/9783319294476

Teaching methods

Frontal lectures with use of multimedial material.

Exercise are done with active intervention by the students.

Assessment methods

Final examination is common to both modules with the aim to verify the ability of the student to apply it knowledge and to do logical reasoning. Normally, it consists of 2 questions for each module, one technical and one more general, all concurring to the final mark.

Mark's ranges:

Preparation on a limited number of topics covered in the course and ability to perform autonomous analysis only on purely executive matters, with correct language → 18-24

Preparation on a wide range of topics covered in the course and ability to carry on autonomous critical analysis, with mastery of terminology → 25-29

Preparation on all topics covered in the course, ability to carry on autonomously critical analysis, and discuss links among the topics → 30-30L

Teaching tools

videoprojector

Office hours

See the website of Federico Porcù

See the website of Laura Sandra Leo

SDGs

Climate Action

This teaching activity contributes to the achievement of the Sustainable Development Goals of the UN 2030 Agenda.