1 / 17

Chapter 7 Ocean Circulation: El Ni ño

Chapter 7 Ocean Circulation: El Ni ño. Essentials of Oceanography 7 th Edition Thurman/Trujillo. El Ni ño-Southern Oscillation (ENSO).

knox-santana
Download Presentation

Chapter 7 Ocean Circulation: El Ni ño

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. Chapter 7 Ocean Circulation:El Niño Essentials of Oceanography 7th Edition Thurman/Trujillo

  2. El Niño-Southern Oscillation (ENSO) • El Niño (Spanish for “the Child” in reference to baby Jesus) = warm surface current in equatorial eastern Pacific that occurs periodically around Christmastime • Southern Oscillation = change in atmospheric pressure over Pacific Ocean accompanying El Niño • ENSO describes a combined oceanic-atmospheric disturbance

  3. Questions about El Niño • What does an El Niño have to do with the price of eggs? • What is La Niña? • What kind of weather does El Niño bring to southern California? • Is this an El Niño year?

  4. Normal conditions in the Pacific Ocean (pg. 218) Figure 7-18a

  5. El Niño conditions (ENSO warm phase) (pg. 218) Figure 7-18b

  6. La Niña conditions (ENSO cool phase; opposite of El Niño) Figure 7-18c

  7. Anomaly maps • Anomaly (a = without, nomos = law) maps show the difference from normal conditions • Sea Surface Temperature (SST) anomaly maps are useful for identifying unusually warm or cool water: • Positive SST anomaly values = water warmer than normal • Negative SST anomaly values = water cooler than normal

  8. January 1998 SST anomaly map Pg. 220 Figure 7-19a

  9. January 2000 SST anomaly map Pg. 220 Figure 7-19b

  10. Offshore California SST anomaly map:January 1998

  11. Offshore California SST anomaly map:January 1999(1 year later)

  12. El Niño/La Niña & weather in southern California • Typical weather during El Niño? • Strong El Niños: Lots of powerful storms (good waves), lots of rain (1997-1998 = more than double our normal rainfall), but not always… • Moderate/Weak El Niños: can have drought conditions or lots of rain or no effect at all • Typical weather during La Niña? • Extremely dry conditions (2000-2001 = 1/3 normal rainfall)

  13. El Niño recurrence interval • Typical recurrence interval for El Niños = 2-12 years • Pacific has alternated between El Niño and La Niña events since 1950 Figure 7-20 Pg. 221

  14. Effects of severe El Niños Pg. 222 Figure 7-21

  15. El Niño visualizations • Internet site for El Niño animation • Latest SST anomaly map of the tropical Pacific

  16. Forecast SST anomalies: Can we expect another El Niño year? • 9-month forecast of tropical Pacific SST anomalies • Alternate link for 9-month forecast of tropical Pacific SST anomalies (from Palomar Oceanography Home Page)

  17. End of El Niño presentation Essentials of Oceanography 7th Edition Thurman/Trujillo

More Related