ATMOSPHERIC SCIENCES 451a/551a                                                                                                           Fall 2010

 

 

Introduction to Physical Meteorology

Last update: 12/19/10

 

 

This is the first semester of a two semester series introducing physical meteorology. The two courses cover the history, composition and chemistry of the atmosphere, kinetic theory, the mechanics of ideal and real fluids, aerosol mechanics, atmospheric radiation, scattering, radiative transfer, cloud physics, energy budget and climate theory, and (if we get to it) atmospheric electricity. 

It is essentially an applied physics course that is a blend of atmospheric science and an order of magnitude physics course I took at Caltech many years ago.  It is designed to teach you how to think physically about the physical processes operating in the atmosphere and related geophysical systems.

 

 

Instructor:                             Rob Kursinski (kursinski@atmo.arizona.edu)

                 

Office:                                      PAS 580

 

Office Hours:                     TBD

 

Course Grading:    Homework                        65 %

                              Midterm (Take-home)      10 %

                              Final                                  15 %

                              Class participation                          10 %

 

Overall Goal:                                                          Teach the students how to think in terms of the physics of the atmosphere and related topics.  Provide a foundation in atmospheric physics suitable for advanced study in the atmospheric sciences and professional employment.

 

Minimum Prerequisites:                                 Understanding of basic physics and mathematics through differential equations

 

Textbooks:                                                               Most relevant text is Wallace and Hobbs, Atmospheric Science


 

35th  Annual  Climate  Diagnostics  and  Prediction  Workshop (CDPW35) Agenda

 

 

Lectures

Rationale                                pdf          doc

Units                                         pdf          doc

Planet Summary              pdf          doc

Radiative Equilibrium Temperature      pdf          doc

Vertical Atmos Structure                               pdf          doc

Impulse & work               pdf          doc

Kinetic pressure of a gas             pdf          doc

1st Law of Thermodynamics   pdf         doc

Specific Heat                      pdf          doc

Latent Heat                          pdf          doc

Gravity                                    pdf          doc

Adiabatic Lapse Rate   pdf          doc

Virtual Temperature     pdf          doc

Water Vapor                       pdf          doc

Entropy Introduction    pdf          doc

Clausius Clapeyron        pdf          doc

Flow over mountain      pdf          doc

Moist adiabat (thermodyn)        pdf          doc

Moist adiabat (microscopic)     pdf          doc

Equivalent Potential Temp.      pdf          doc

CAPE                                       pdf         doc

Subsidence                           pdf          doc

Carnot Cycle                      pdf          doc

Diffusion                                pdf          doc

Diffusive fluxes                pdf          doc

Mexico Fluxes                   pdf

Drag Coefficients            pdf

Boundary Layers            pdf          doc

PBL (Rob Wood)           pdf

Droplet fall speed            pdf          doc

Rad. Transfer Intro       pdf          doc

Planck Function              pdf          doc

Optical Depth                     pdf          doc

Crosssections                     pdf          doc

Cirrus measurements   pdf

Scattering Intro                 pdf          doc

Mie Scat Intro                   pdf          doc

Gas absorption                  pdf          doc

Line shapes                          pdf          doc

 

 

 Homework

 

Hwk1                     pdf          doc         Solution                pdf          doc

Hwk2                     pdf          doc         Solution                pdf          doc

Hwk3                     pdf          doc         Solution                pdf          doc

Hwk4                     pdf          doc         Solution                pdf          doc

 

I will assign homework that is based on the material covered in the lectures and class handouts.  Several points:

 

  1. Homework problems are best done individually, but you can certainly discuss your methods and the results with other students in the class.  Students can sometimes learn more by discussing the ideas and methods with others than they can on their own, especially at the beginning of the course.  Also, each of you has a different perspective and background, and the views of others can often be beneficial to a larger group. Do NOT copy your solutions from anyone else, and if your ideas and methods are not your own, please tell me that on the papers you turn in.

 

2.    Homework problems will be assigned a week before they are due.  Graded homework with solutions will be returned.

 

3.   I am lenient about late homework; homework will usually be accepted for full credit as long as solutions have not been distributed in class.  However, because of this policy and the completeness of the solutions that will be distributed, any homework received after the solutions are distributed WILL NOT BE ACCEPTED for credit.

 

 


COURSE OUTLINE 451/551

 

Note:  Some of these subjects will be covered in less detail than others.

 

We will get through a good part of the radiative transfer to allow those student who want to take the 656b remote sensing course in Spring 2011 to be better prepared.

 

1)       Rationale: Why are we interested in the Atmospheric Sciences?

2)       Introduction and Basic Concepts

a.        Composition: gases and particles

b.        Gravitation: NewtonÕs law, g, satellite orbits

c.        Mass density

d.        Barometers and pressure

e.        Hydrostatic equation

f.          Gas law and temperature

g.        Scale heights

h.        Other Planets

3)       Thermodynamics and Kinetic Theory of gases

a.        Temperature, Heat and Energy

                                                                       i.       Thermodynamic Definition of T

                                                                      ii.       1st and 2nd laws of thermodynamics

                                                                    iii.       Intro to kinetic theory – temperature, heat and internal energy

                                                                    iv.       Measurements of temperature

                                                                     v.       Vertical, meridional, diurnal, seasonal, + climatic variations in Temperature

b.        Pressure, and Work

                                                                       i.       Pressure as F/A and isotropic nature

1.        NewtonÕs laws

2.        Work-energy thm.

                                                                      ii.       Hydrostatic approximation

1.        Gravitation

2.        Geopotential Height

                                                                    iii.       Kinetic explanation of pressure and work

1.        Impulse momentum Thm

                                                                    iv.       1st law of thermodynamics revisited

1.        Isothermal/Adiabatic processes

2.        Heat capacity at const pressure

3.        Potential temperature

4.        Adiabatic lapse rate

5.        Adiabatic pressure profiles

                                                                     v.       Buoyancy

                                                                    vi.       Barometers

                                                                  vii.       Observed variations in pressure – quick deference to 541a,b

c.        Humidity

                                                                       i.       Quantifying humidity

                                                                      ii.       Effects on ideal gas law

                                                                    iii.       Effects on heat capacity

                                                                    iv.       Latent heat

                                                                     v.       Clausius clapyron equation

                                                                    vi.       Moist adiabatic lapse rate

                                                                  vii.       Air flow over a mountain

                                                                 viii.       Buoyancy revisited

                                                                    ix.       Distributions of humidity

                                                                     x.       The convective heat engine

                                                                    xi.       Measuring humidity

                                                                  xii.       Distributions of surface heat & moisture fluxes (after diffusion)

4)       Radiation

a.        The electromagnetic spectrum

b.        Measures of radiation and solid angle

c.        Blackbody laws

d.        Transitions and lines / Broadening / Atmospheric Spectra

e.        2-stream IR radiative transfer + greenhouse effect

f.          The sun

g.        The solar cycle

h.        Single-Scattering

                                                                       i.       Formal Rayleigh scattering

                                                                      ii.       Mie Scattering/absorption

                                                                    iii.       Geometric approximation

i.          Plane parallel Applications

                                                                       i.       Aerosols / Optical depth

                                                                      ii.       Clouds

                                                                    iii.       Variation of sky radiance for thin atmosphere

                                                                    iv.       2-stream multiple scattering solutions - conservative

                                                                     v.       2-stream multiple scattering solutions – non-conservative + semi-infinite atmosphere approx.

5)       Radiation budget + climate

a.        Simple radiation budget

b.        Equilibrium models

c.        Layers of tau=1

d.        Convection

e.        Advection

f.          Radiative Forcing + Feedback

g.        Geological records + Milankovich cycles

h.        Role of oceans

i.          Role of surface ice

j.          The true Gordian knot – feedbacks with biosphere

k.        Role of Clouds: TrenberthÕs point about short wave vs longwave

l.          Changing vertical fluxes in a warmer climate

6)       Atmospheric Chemistry

a.        Chemical reactions in the atmosphere

b.        Equilbrium and rate equations

c.        Kinetic theory and the frequency of 2-body and 3-body collisions

                                                                       i.       Mean free path

                                                                      ii.       Collisional cross-section

d.        Stratospheric photochemistry: Ozone + Chapman mechanism

                                                                       i.       Basics of photochemistry – actinic fluxes + cross-sections – analogy with kinetic theory

                                                                      ii.       Importance of nitrogen

                                                                    iii.       Importance of CFCs

e.        Tropospheric chemistry: NOx, OH and VOCs

f.          Water and why homogeneous nucleation of droplets wonÕt happen (as segue)

7)       Diffusion + Condensation (Under cloud physics and chemistry umbrellas)

a.        Using kinetic theory for diffusion of species

b.        Continuous diffusion equation and applications

                                                                       i.       Connection to heat transfer equation

c.        Diffusion to a sphere

d.        Heat diffusion vs. vapor diffusion

e.        Droplet growth equation – sans Kšhler theory

8)       Basic fluid mechanics

a.        Navier-Stokes Equations (briefly)

b.        Acoustics (briefly)

c.        Stress tensor

d.        Kinetic formulation for dynamic (and kinematic) viscosities as diffusion of momentum

e.        Kinematics of fluid motion

f.          Dimensional analysis

g.        ReynoldsÕs # + Stokes flow

h.        High-ReynoldsÕs # flow

                                                                       i.       BernoulliÕs equation

                                                                      ii.       Basics of turbulence – Kolmolgorov length scale, power-laws

                                                                    iii.       Turbulent diffusion coefficients

9)       The atmospheric aerosol + Particle mechanics

a.        Survey of aerosols in atmosphere

b.        Formality of size distributions – moments, etc.

c.        2-phase flow mechanics –

                                                                       i.       Drag forces + particle motion

                                                                      ii.       Diffusion Coagulation

                                                                    iii.       Graviational and Shear-induced coagulation

10)   Cloud microphysics

a.        Kšhler theory + CCN

b.        Growth of a population of droplets

c.        Cloud dynamics

d.        Ice

e.        Precipitation