1 / 55

El Niño/Southern Oscillation

El Niño/Southern Oscillation. Major climatic perturbation on the planet Coupled atmosphere ocean process Key is the western tropical Pacific Ascending branch of the Walker circulation Potential energy for Kelvin wave pulse www.pmel.noaa.gov/tao/elnino/nino-home.html.

noel
Download Presentation

El Niño/Southern Oscillation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. El Niño/Southern Oscillation • Major climatic perturbation on the planet • Coupled atmosphere ocean process • Key is the western tropical Pacific • Ascending branch of the Walker circulation • Potential energy for Kelvin wave pulse • www.pmel.noaa.gov/tao/elnino/nino-home.html

  2. The Southern Oscillation • Discovered in 1928 by Sir Gilbert Walker • Links D’s in global climate indices • Proposes a zonal circulation cell over the equatorial Pacific

  3. The Southern Oscillation

  4. The Southern Oscillation • Pressure D’s regulate strength of the trades • El Niño periods = weak trades

  5. Southern Oscillation Index • SOI = Tahiti - Darwin air pressure D’s • Low SOI = El Niño conditions

  6. Southern Oscillation Index

  7. Southern Oscillation

  8. Walker Circulation • East-to-west pressure gradients drive trades

  9. Walker Circulation • Vertical cell driven by warmest waters

  10. Western Pacific Warm Pool

  11. Coupled Walker/Ocean Circulation

  12. TOGA-TAO Array • Equatorial array of buoys (also Atlantic & Indian) • U.S., Japan, India, French, etc. partnership • http://www.pmel.noaa.gov/tao/

  13. Moorings • Measure met & ocean properties • Thermocline focus • Real-time data transmission • Used in weather & climate forecasts

  14. TAO Moorings

  15. TAO Moorings

  16. Southern Oscillation

  17. El Niño Conditions

  18. El NiñoEvents • Relaxation of trades causes warm pool to slosh across Pacific basin

  19. El Niño Conditions

  20. La Nina • Opposite phase of the ENSO cycle • Intensified trades & Walker circulation • Thermocline undergoes maximum upwelling

  21. Altimetry & ENSO States • Most “action” is in the tropical Pacific • Effects are seen in other places • East subtropics • Western NECC region

  22. Equatorial Kelvin Waves • Satellite altimetry from TOPEX/Poseidon • Scenes are 10 days apart

  23. Equatorial Kelvin & Rossby Waves

  24. Off-Equatorial Rossby Waves Equatorial Kelvin Waves

  25. Planetary Waves & El Niños

  26. Effects of an El Niño • Region of ascending air has moved to center of equatorial Pacific • Climate system shifts over 10,000 km to east • Affects the entire planet

  27. Effects of an El Niño • Places that were wet are now dry and vice versa

  28. Effects of an El Niño

  29. Teleconnections • Discovered in 1928 by Sir Gilbert Walker • Links D’s in global climate indices • Proposes a zonal circulation cell over the equatorial Pacific

  30. El Niño & Hurricane Damage

  31. El Niño & Diseases

  32. El Niño • Hadley cells intensify as source of heat is now in central equatorial Pacific • Jet stream intensifies & takes south path

  33. El Niño in the United States

  34. El Niño in the United States

  35. El Niño in California

  36. El Niño in California

  37. El Niño in California

  38. 97/98 El Niño • At its peak, the 97/98 El Niño was biggest of all time

  39. 97/98 El Niño

  40. 97/98 El Niño

  41. 97/98 El Niño • TOPEX/Poseidon sea level anomaly - December 1, 1997

  42. 97/98 El Niño

  43. 97/98 El Niño OLR = outgoing longwave energy (high OLR = no clouds)

  44. 97/98 El Niño

  45. Present Conditions

  46. Present Conditions EL NIÑO/SOUTHERN OSCILLATION (ENSO)DIAGNOSTIC DISCUSSION 5 January 2012 Synopsis: La Niña is expected to continue into the Northern spring 2012.

  47. Present Conditions

  48. Nino Regions

More Related