ATM S 340, Winter 1998

Introduction to Thermodynamics & Cloud Processes

Instructor: Professor Peter V. Hobbs
504 Atmospheric Sciences Bldg., 543-6027
phobbs@atmos.washington.edu

Lectures: MTWThF, 9:30-10:20 AM, Room 310C ATG

Midterm Exam: February 6, 9:30-10:20 AM

Final Exam: Wednesday, March 18, 8:30-10:20 AM

Grading: Quizes (based on "homework") = 20%; Midterm (1) = 40%; Final = 40%

Textbook: Atmospheric Sciences: An Introductory Survey, by J.M. Wallace and P.V. Hobbs (1st Ed., Academic Press)

Study Time Outside of Class: About 7 hours per week

Purpose of Course:

  1. To review the basic concepts of thermodynamics and to apply these concepts to the atmosphere.

  2. To provide an introduction to the physical processes leading to the formation of clouds, rain, snow and thunderstorm electrification.

Course Outline:

Class Day
Topic
Part I: Basic Thermodynamics
1
 Organization and structure of course. First Law of Thermodynamics
2
 Some applications of 1st Law; latent heat
3
 Properties of gases; the ideal gas scale of temperature
4
 Ideal gases; Joule's Law; specific heats of an ideal gas
5
 Adiabatic transformations of an ideal gas; Principle of Equipartition of Energy
6
 Second law of Thermodynamics; Carnot's ideas on a "cyclic process" and reversibility
7
 Second Law of Thermodynamics: Carnot's Cycle, statements of 2nd Law, Carnot's Theorems
8
 Kelvin's absolute scale of temperature; absolute zero of temperature
9
 Relation between the absolute and ideal gas scales of temperature; efficiency of an ideal heat engine
10
 Quiz
11
 Entropy; entropy-temperature diagram
12
 Entropy of an ideal gas; Principle of Increase of Entropy; reversible and irreversible processes; available energy
13
 Clausius-Clapeyron Equation; applications of Clausius-Clapeyron Equation; 2nd Latent Heat Equation
14
 Quiz
15
 Thermodynamic functions and relations; Maxwell's equations

Part 2: Atmospheric Thermodynamics
16
 Definitions for mixtures; composition of dry air
17
 Gas equation for dry air; gas equation for water vapor
18
 Specification of water vapor in air
19
 Quiz
20
 Gas equation for moist air; virtual temperature
21
 Hydrostatic equation; geopotential; scale height; hypsometric equation
22
 Thickness; reduction of pressure to sea level
23
 Application of 1st Law of Thermodynamics to the atmosphere; static energy
24
 MID-TERM EXAM
25
 REVIEW OF MID-TERM EXAM
26
 Dry adiabatic lapse rate; stability of dry air
27
 Potential temperature; relationship between potential temperature and entropy
28
 Pseudo-adiabatic chart; stability and potential temperature
29
 Quiz
30
 Potential density; mirages
31
 Entropy-temperature diagram; thermodynamics of saturated air: wet-bulb temperature, saturated adiabatic lapse rate, pseudo-adiabatic processes
32
 Thermodynamics of saturated air (cont.): wet-bulb temperature, saturated adiabatic lapse rate
33
 Quiz
34
 Thermodynamics of saturated air (cont.): equivalent potential temperature, wet-bulb potential temperature, Normand's rule
35
 Solving problems with the pseudo-adiabatic chart; stability of saturated air; conditional instability; convective instability
36
 Cloud types; processes for forming and modifying clouds

Part 3: Cloud and Precipitation Processes
37
 Photographs of clouds
38
 Quiz
39
 Homogeneous nucleation of water drops; Kelvin's equation
40
 Atmospheric aerosol; heterogenous nucleation of drops
41
 Köhler curves. Cloud condensation nuclei
42
 Cloud microstructures; growth of drops by condensation
43
 Quiz
44
 Growth of drops by collisions
45
 Ice in clouds. Growth of ice crystals from vapor phase and by riming and aggregation
46
 Thunderstorms
47
 Artificial modification of clouds
48
 Quiz
49
 FINAL EXAM

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