Introduction to Tropical Meteorology, 2nd Edition, Chapter 4: Tropical Variability

Introduction to Tropical Meteorology, 2nd Edition, Chapter 4: Tropical Variability

At the end of this chapter, you should understand and be able to:

  • Describe the basic structure and time scale of the MJO
  • Discuss the mechanisms that form the MJO
  • Explain the role of the MJO in atmospheric and oceanic variability
  • Describe the general characteristics of equatorial waves (Kelvin waves, Rossby waves, Mixed Rossby-Gravity waves) including length scale, duration, and speed
  • Explain equatorial wave formation mechanisms graphically or mathematically
  • Describe the Walker Circulation
  • Define the Southern Oscillation Index
  • Describe ENSO in terms of onset, maximum amplitude, and duration
  • Describe the previous and current theories of ENSO (from Bjerknes to recent theories such as the delayed oscillator theory or chaotic theory)
  • Compare and contrast the warm phase (El Niño) and cold phase (La Niña) patterns in terms of atmospheric and oceanic anomalies across the equatorial Pacific
  • Describe at least five climate impacts of El Niño (e.g., drought in Australia, heavy rains in Peru, more winter cyclones across the southern US and the Caribbean, less hurricanes in the Atlantic)
  • Describe at least five climate impacts of La Niña (e.g., increased rainfall in West Pacific, drier winter in the southeastern US, wetter summers in the Caribbean and Central America)
  • Define the Quasi Biennial Oscillation
  • Describe its impact on tropical climate (e.g., influencing seasonal tropical cyclone formation)
  • Provide a brief description of the Pacific Decadal Oscillation, the Atlantic Multidecadal Oscillation, and the North Atlantic Oscillation
  • Describe at least one mechanism by which the tropics can force decadal extratropical variability in the North Atlantic and the North Pacific
  • Describe at least one impact of decadal fluctuations on interannual and intraseasonal variability