Presentation on theme: "SIO 210: ENSO conclusion Dec. 2, 2004 Interannual variability (end of this lecture + next) –Tropical Pacific: El Nino/Southern Oscillation –Southern Ocean."— Presentation transcript:
SIO 210: ENSO conclusion Dec. 2, 2004 Interannual variability (end of this lecture + next) –Tropical Pacific: El Nino/Southern Oscillation –Southern Ocean imprint of ENSO –Tropical Atlantic: dipole mode This powerpoint was prepared for purposes of this lecture and course only. It contains graphics from copyrighted books and journals. Please do not use without acknowledgment of these sources.
ENSO: normal and La Nina conditions http://www.pmel.noaa.gov/tao/elnino/nino_normal.html
ENSO: El Nino conditions http://www.pmel.noaa.gov/tao/elnino/nino_normal.html
Map to show location of Tahiti and Darwin Tahiti Darwin Walker cell: low pressure at Darwin, high pressure at Tahiti Southern Oscillation Index: Tahiti SLP minus Darwin SLP
Southern Oscilllation index (NCEP) During El Nino: SOI is low: Tahiti minus Darwin is low, meaning that the pressure difference between them is reduced. Therefore the trade winds are weaker during ENSO. Note that Darwin and Tahiti anomalies are out of phase El Ninos: low SOI http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/bulletin/index.html
ENSO indices: based on SST. Most commonly used is the Nino3 or Nino3,4 http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/bulletin
USA impacts of El Nino and La Nina: temperature
USA impacts of El Nino and La Nina: precipitation
Compare with SW US monsoon: monsoon is pretty much the same pattern as ENSO ENSO monsoon
El Nino - where are we right now? An El Nino event is building, and predictions of this winter’s conditions in N. America are related to it.
El Nino We are in a weak El Nino pattern now. NOAA Climate Prediction Center winter 2004-2005 patterns prediction: Figure 5. Seasonal U. S. temperature (left) and precipitation (right) outlooks for December 2004-February 2005. Outlooks prepared in mid-September 2004 reflect a blend of ENSO-related impacts and long-term trends. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_advisory/ warm dry cool wet
El Nino Great websites: http://www.pmel.noaa.gov/tao/elnino/nino-home.html http://topex-www.jpl.nasa.gov/science/el-nino.html