Geo 232: Climate Dynamics

Ray Pierrehumbert, Liz Moyer

TA: Ari Solomon

Problem Set 3 4 and 5 solutions posted; Scroll to bottom to download

Fall 2009 Take-home final is : here.

This page holds notes and materials from the Fall 2009 U. Chicago version of this course. The course will cover thermodynamics and radiation in planetary atmospheres, energy balance and vertical motions. Interested students are advised to continue with two geophysical fluid dynamics courses in the Winter and Spring quarters (GEOS 342, Pierrehumbert, and GEOS 344, Nakamura, respectively). These will cover winds, waves, turbulence, and general circulation of the atmosphere. Fluid dynamics of the ocean is covered in a Winter quarter course (GEOS 235/335, MacAyeal).

General notes on the course from last year and notes on Python are here. Ray's climate book is found on his textbook page (as a very large pdf file here , with last year's problem sets here). Many other textbooks hold good introductions to atmospheric thermodynamics and radiation and can be used as references. We'll put some on reserve at Crerar.

The course meets Mondays and Wednesday from 1:30-3:00 PM in Hinds 584. Section meetings will be arranged. General email to the entire course list is geos23200_08@lists.uchicago.edu. Currently all students can send to this list, but be judicious in your choice of what to send.

Course grades are based on problem sets, final exam or project, and classroom discussion. Some problem sets involving programming will have to be done in Python as they involve pre-written scripts (unless you want to rewrite these in the language of your choice). Other assignments can be done in any language. The TA is only giving programming advice for Python, though... and if you program in a language he doesn't know, he might not be able to give you partial credit for answers. Problem sets will generally be given out on Mondays and due the following Monday. Late policy is at the discretion of the TA; you must inform him in advance and negotiate a reasonable solution if you have a punctuality crisis.

Course syllabus and notes

The draft syllabus below may evolve as the course progresses. If/when we write up lecture notes for the different lectures, we'll put them here as live links to pdf files. A "---" doesn't meant "no section this week"; it just means that we haven't decided yet what that section will entail. NOTE: This is the 2008 syllabus. In 2009 we will spend more time on paleoclimate basics ("Big Questions"), then do radiation balance first, in October, then do thermodynamics.

Introduction

Lecture 1: Introduction: big problems in climate (R)

Lecture 2: Order-of-magnitude estimation: pressure, water vapor, latent heat flux (L)

Structure and thermodynamics of a dry atmosphere

Lecture 3: Hydrostatics, ideal gas law (L)

Lecture 4: Energy, entropy, potential temperature, stratification, and the dry adiabat (L)

Section 1: Introduction to Python

Adding water

Lecture 5: Phase changes, latent heat, and Clausius-Clapeyron (R)

Lecture 6: Structure of a wet atmosphere: the moist adiabat (R)

Section 2: Problem set review

Wet atmospheres continued

Lecture 7: Moist atmospheres cont. (R)

Lecture 8: Moist atmospheres cont. (R)

Section 3: ----

Wet atmospheres continued

Lecture 9: The moist adiabat (R)

Lecture 10: Condensation and basics of convection (L)

Section 4: Python: Making and plotting functions

Introduction to radiation

Lecture 11: Introduction to planetary energy balance (L)

Lecture 12: Electromagnetic radiation, Planck's constant and quantization. Working with spectra. (R)

Section 5: ----

Absorption in the Earth's atmosphere

Lecture 13: Blackbody radiation, emission spectra of sun and Earth (R or L)

Lecture 14: Atmospheric absorption, CO2 and H2O spectra (R or L)

Section 6: ----

Climate changes: greenhouse warming, ice albedo feedback

Lecture 15: Greenhouse forcing in more detail (R or L)

Lecture 16: ice albedo and "Snowball Earth"(R or L)

Section 7: ice albedo, stochastic forcing, multiple climate states

Water vapor feedback

Lecture 17: simulating water vapor feedback forced by CO2 (R or L)

Lecture 18: indirect effects: clouds; paleodata (R or L)

Section 8: numerical simulation of water vapor feedback

The stratosphere

Lecture 19: Partially absorbing atmospheres. emissivity and Kirchoff's Law (R or L)

Lecture 20: Radiative equilibrium for optically thin atmospheres. Skin temperature. Basic theory of the stratosphere. Effect of solar absorption on stratospheric temperature (R or L)

Section 9: ----

If time, intro to radiative transfer, Schwartzschild equations

Additional Reading

Derivation of Clausius-Clapeyron: Feynman Lectures Vol I (Section 45-3) has a very concise physically based derivation. The Wikipedia page on Clausius-Clapeyron gives a more formal derivation.

Before doing Problem Set 3, please read the differential equation tutorial material here Read the sample Python scripts to make sure you understand how to implement the algorithms. Try running the scripts by copying from a browser window and pasting into an IDLE editor window.