1. ENSO (El Nino Southern Oscillation) ENVS 110 10-12-2008

2. http://upload.wikimedia.org/wikipedia/commons/1/18/Wiki_plot_03.png

3. http://www.pmel.noaa.gov/pubs/outstand/kess2580/images/fig01.gif

4. http://www.sbg.ac.at/ipk/avstudio/pierofun/atmo/el-scans/el-nino1.jpg

6. http://www.sbg.ac.at/ipk/avstudio/pierofun/atmo/el-scans/walker.jpg

8. http://www.sbg.ac.at/ipk/avstudio/pierofun/atmo/el-scans/el-nino2.jpg

9. Normal Conditions: West Pacific Warm Pool

10. El Nino Conditions

11. http://www.sbg.ac.at/ipk/avstudio/pierofun/atmo/el-scans/catch.jpg

12. El Nino forecasting Careful monitoring of – Oceanic temperatures (satellites) – Strength of trade winds sometimes it works – sometimes it doesn’t

15. How to measure sea surface temperatures (old school) automated buoys (get spot measurement, often temperature profile) → buoy arrays temperature recorders in the water intakes of big ships → variable locations, sampling depth might not be constant (loaded vs. empty vessel) but greater geographical coverage

16. How to Measure Sea Surface Temperatures from Satellites? infrared radiation problem: cannot see through clouds, aerosols electromagnetic radiation at other wavelengths – microwave radiation (can see through clouds and aerosols, but is scattered by raindrops)

17. http://www.sciencemag.org/cgi/content/full/288/5467/847

18. how to measure ocean temperature at depth ? warm water is less dense → takes up more space (floats on top of colder water) sea surface rises 50 m of 1C warmer water raises sea surface by approximately 1 cm after lots of correlations, corrections and other trickery → get temperature distribution with depth

19. Historical variations Red: El Nino Blue: La Nina

20. How can you Reconstruct ENSO Cycles ? Expressed as: – sea surface temperature anomalies – air temperature, atmospheric pressure anomalies in Pacific – precipitation ? – economic effects ? – climate effects outside equatorial Pacific?

21. Where is atmospheric pressure high, where is it low ?

22. source: http://www.worldatlas.com/webimage/countrys/islands/pacifics/tahiti.htm

23. DarwinTahiti

24. The Southern Oscillation Index (SOI) expresses difference in barometric pressure between Australia (Darwin) and Thaiti several ways to calculate P diff = MSLP Thaiti - MSLP Darwin sustained negative values: El Nino sustained positive values: La Nina

26. Source: Commonwealth of Australia 2006, Bureau of Meteorology (ABN 92 637 533 532) http://www.bom.gov.au/climate/current/soi2.shtmlhttp://www.bom.gov.au/climate/current/soi2.shtml (accessed 3/13/06)

27. ENSO Cycles El Nino – La Nina phenomenon is cyclical Note timescales involved How rapidly does atmosphere change ? How rapidly do oceans change ? Oceans are a good place to look for drivers of short term climate change

28. http://www.sbg.ac.at/ipk/avstudio/pierofun/atmo/el-scans/rain.jpg