Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.
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Transcript of Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.
![Page 1: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/1.jpg)
Chapter 7 Ocean Circulation:
El Niño
Essentials of Oceanography
7th Edition
Thurman/Trujillo
![Page 2: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/2.jpg)
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 ChristmastimeSouthern Oscillation = change in atmospheric pressure over Pacific Ocean accompanying El NiñoENSO describes a combined oceanic-atmospheric disturbance
![Page 3: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/3.jpg)
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?
![Page 4: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/4.jpg)
Normal conditions in the Pacific Ocean (pg. 218)
Figure 7-18a
![Page 5: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/5.jpg)
El Niño conditions (ENSO warm phase) (pg. 218)
Figure 7-18b
![Page 6: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/6.jpg)
La Niña conditions (ENSO cool phase; opposite of El Niño)
Figure 7-18c
![Page 7: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/7.jpg)
Anomaly maps
Anomaly (a = without, nomos = law) maps show the difference from normal conditionsSea Surface Temperature (SST) anomaly maps are useful for identifying unusually warm or cool water:Positive SST anomaly values = water warmer than normalNegative SST anomaly values = water cooler than normal
![Page 8: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/8.jpg)
January 1998 SST anomaly map
Figure 7-19aPg. 220
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January 2000 SST anomaly map
Figure 7-19bPg. 220
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Offshore California
SST anomaly map:
January 1998
![Page 11: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/11.jpg)
Offshore California
SST anomaly map:
January 1999
(1 year later)
![Page 12: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/12.jpg)
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)
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El Niño recurrence interval
Typical recurrence interval for El Niños = 2-12 yearsPacific has alternated between El Niño and La Niña events since 1950
Figure 7-20
Pg. 221
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Effects of severe El Niños
Figure 7-21
Pg. 222
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El Niño visualizations
Internet site for El Niño animation
Latest SST anomaly map of the tropical Pacific
![Page 16: Chapter 7 Ocean Circulation: El Niño Essentials of Oceanography 7 th Edition Thurman/Trujillo.](https://reader033.fdocuments.in/reader033/viewer/2022061612/56649da55503460f94a90987/html5/thumbnails/16.jpg)
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)
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End of El Niño presentation
Essentials of Oceanography
7th Edition
Thurman/Trujillo