Embed Size (px)
Citation preview
El Nino
El Nino – Typical surface ocean circulation
El nino conditions
• Normal
• El nino – strong counter-current
El nino conditions
• Normal
• El nino – strong countercurrent
• Prentice Hall Textbook animation link
El Nino: Normal Conditions
• Prentice Hall Textbook animation link
El Nino: El Nino Development
• Prentice Hall Textbook animation link
El Nino: La Nina
Winter NH
• El Nino
• La Nina
Summer NH
• El Nino
• La Nina
El nino - precipitation
El nino - precipitation
Typical winter Effects
• El Nino
• La Nina
http://www.cpc.noaa.gov/products/analysis_monitoring/ensocycle/nawinter.html
El Nino – weak Aleutian High
La Nina – strong Aleutian High
El Nino: US Winter Temperatures
• Higher in mid continent• Lower in south
El Nino: US Winter Precipitation
• Higher in south and coastal regions
Flooding in San Francisco
During the winter of 1997-98, wind-driven waves and abnormally high sea levels significantly contributed to hundreds of millions of dollars in flood and storm damage in the San Francisco Bay region. Recent analyses by U.S. Geological Survey (USGS) scientists of nearly 100 years of sea-level records collected near the Golden Gate Bridge found that these abnormally high sea levels were the direct result of that year's El Niño atmospheric phenomenon.
Flooding in San Francisco
• Less land sea winds with El nino conditions result in higher sea level.
http://geopubs.wr.usgs.gov/fact-sheet/fs175-99/
Hurricanes• El Niño contributes to more eastern Pacific hurricanes and fewer
Atlantic hurricanes. – Average US damage = $5.9 billion
• La Niña contributes to fewer eastern Pacific hurricanes and more Atlantic hurricanes.– Average US damage = $2.0 billion
US hurricane damage
US TornadosTornado activity
Depends on the location of the polar jet stream (and thus the location an movement of mid-latitude cyclones)
• El Nino: More to the south
• La Nina: more to the north
AKprecip
(in)
• El Nino:
• Nov- Dec
AKTemperature
• El Nino:
• Feb - Apr
Prediction of El Nino• Satellites
– provide data on tropical rainfall, wind, and ocean temperature patterns, as well as changes in conditions for hurricane formation.
• Ocean buoys – help to monitor sea-surface and upper ocean
temperatures.
• Radiosondes – balloon-borne instrument platforms with radio
transmitting capabilities, help to monitor global weather and climate patterns
• Super computers – gather all of the weather data around the world and
put it into useful formats used by scientists.– Run models for future change
