1. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 CHAPTER 6 OCEAN–ATMOSPHERE INTERACTIONS

2. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 INTRODUCTION Oceans on a global scale The geography of ocean currents Significant interactions between the ocean and the atmosphere Ocean–atmosphere research, TOGA/COARE Ocean circulation and heat transport –The surface currents –The deep ocean ‘conveyor belt’

3. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 OCEAN CHARACTERISTICS Physical characteristics –Temperature –Density –Salinity –Chemistry Vertical structure Upwelling –and coastal deserts The Ekman Spiral

4. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 THE OCEANS AND ATMOSPHERIC INSTABILITY General impacts Intertropical Convergence Zone –Geographical location –Relation to the Hadley circulation –Impacts on the atmosphere

5. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 THE SOUTHERN OSCILLATION Definitions The Walker circulation Southern Oscillation Index (SOI)

6. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 El Niño (ENSO) Circulation changes Sea-surface temperature Precipitation impacts Variability over past decades Global impacts (teleconnections) Impacts on Australia

7. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 La Niña Opposite of El Niño Circulation changes Sea surface temperature Impact on precipitation Impacts on Australia

8. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 TROPICAL CYCLONES Definition Requirements for formation –Warm SST –Coriolis force –Pre-existing depression –Weak vertical wind shear –Upper level outflow exceeds lower level inflow

9. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 TROPICAL CYCLONES Incipient stage Mature stage –Eye formation and characteristics –The convective cloud band –Outside the cloud wall Dissipation Geographical distribution Saffir–Simpson damage scale Cyclone Tracy in Darwin

10. © Oxford University Press, 2008. All rights reserved. 1 Chapter 6 ANTARCTIC CIRCUMPOLAR LOWS Definition Effects of katabatic winds Influence of Coriolis force