1 -- INTRODUCTION

1.1 Lecture Objectives

2 -- OVERVIEW OF THE STRATOSPHERE'S COMPOSITION, STRUCTURE, AND DYNAMICS

2.1 The Density and Temperature of Air

2.1.1 Air Density Change With Altitude

2.1.2 Air Temperature Change With Altitude

2.1.3 The Tropopause

2.2 Potential Temperature and the Stability of Stratospheric Air

2.2.1 Static Stability

2.2.2 Potential Temperature and Static Stability

2.2.3 Potential Temperature Profile in the Stratosphere

2.2.4 Isentropic Surfaces and the Motion of Stratospheric Air

2.2.5 Potential Temperature as a Vertical Coordinate

2.3 Air Composition and Its Well-Mixed Nature

2.3.1 Turbulent Diffusion and the Homosphere

2.3.2 The Heterosphere

2.3.3 Trace Gas Variability

2.4 The Stratosphere

2.4.1 Position of the Tropopause

2.4.2 Regions of the Stratosphere

         (a) The tropics

         (b) The surf zone

         (c) The polar vortex

         (d) The lowermost stratosphere

3 -- THE BREWER-DOBSON CIRCULATION

3.1 Stratospheric Circulation: the Big Picture

3.2 The Brewer-Dobson Circulation in the Tropics

3.2.1 Ozone Source Region

3.2.2 CFC Transport

3.3 The Brewer-Dobson Circulation in the Extratropical Latitudes

3.4 Theory of the Brewer-Dobson Circulation: Why Does It Exist?

3.4.1 Standing Planetary Waves and Wave Breaking

3.4.2 Polar Night Jet Deceleration and Radiative Imbalance

3.4.3 Sinking Air and Meridional Overturning

3.4.4 Brewer-Dobson and Radiative Balance

3.5 Hemispheric Differences In Winter Transport

3.5.1 Hemispheric Differences in Planetary Wave Activity

3.5.2 Seasonal Hemispheric Differences in Methane Distribution

3.6 Hemispheric Differences In Spring Transport

3.7 The Quasi-Biennial Oscillation (QBO) and the Brewer-Dobson Circulation

3.7.1 What is the QBO?

         (a) Equatorial zonal wind QBO

         (b) Temperature QBO

         (c) QBO circulation

3.7.2 Ozone Transport: Influence of the QBO

         (a) Tropical ozone QBO

         (b) Extratropical ozone QBO

         (c) Theoretical explanation of the QBO

3.8 Circulation Patterns Outside the Stratosphere

3.8.1 Tropospheric Meridional Circulation

3.8.2 Mesospheric Mean Meridional Circulation

3.9 Age-of-Air in the Stratosphere

4 -- ATMOSPHERIC WAVES AND TRANSPORT OF TRACERS

4.1 Extratropical Rossby Waves and Gravity Waves

4.1.1 Rossby Waves: An Illustration<

4.1.2 Wave Theory

         (a) Origin of planetary wave forcing

         (b) Movement

         (c) Wave growth and dissipation

              (1) thermal dissipation

              (2) wave breaking

4.2 Wave Transport

4.2.1 Wave Mixing

4.2.2 The Stratospheric Surf Zone

4.2.3 Wave Influence on Mean Circulation

5 -- STRATOSPHERIC-TROPOSPHERIC EXCHANGE

5.1 Mean Meridional Circulation in the Overworld and the Lowermost Stratosphere

5.1.1 Blocking Anticyclones (Highs)

5.1.2 Cut-Off Low Pressure Systems

5.1.3 Tropopause Folds

SUMMARY

REVIEW QUESTIONS