news 8 girl scout day november 1, 2008 [email protected] “the el nino phenomenon”...
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News 8 Girl Scout DayNews 8 Girl Scout DayNovember 1, 2008November 1, 2008
[email protected]@news8austin.com
““The El Nino Phenomenon”The El Nino Phenomenon”News 8 Austin WeatherNews 8 Austin Weather
Burton Fitzsimmons Burton Fitzsimmons
Earth’s AtmosphereEarth’s Atmosphere
Defined: a layer Defined: a layer of gasses of gasses
surrounding surrounding planet Earth planet Earth
that’s retained that’s retained by Earth’s gravityby Earth’s gravity
Nitrogen 78%Nitrogen 78%Oxygen 21%Oxygen 21%Argon 1%Argon 1%Water Vapor 1%Water Vapor 1%
Satellite/Radar LoopSatellite/Radar Loop
Satellite LoopSatellite Loop
Satellite LoopSatellite Loop
El NinoEl NinoDefined: a global coupled ocean-atmosphere Defined: a global coupled ocean-atmosphere phenomenonphenomenon
In the Pacific ocean, El Nino (“the little boy”) and La In the Pacific ocean, El Nino (“the little boy”) and La Nina (“the little girl”) – noticed off the west coast of Nina (“the little girl”) – noticed off the west coast of South America around Christmas time first in 1923.South America around Christmas time first in 1923.
El Nino – warming of the equatorial Pacific waters; El Nino – warming of the equatorial Pacific waters; seems to occur once every 3 to 7 yearsseems to occur once every 3 to 7 years
La Nina – cooling of the equatorial Pacific watersLa Nina – cooling of the equatorial Pacific waters
What and how do we What and how do we know?know?
El Niño as a physical occurrence is a El Niño as a physical occurrence is a proven fact. The way it works is a proven fact. The way it works is a theory.theory.
Difficult to predict start of cycle but Difficult to predict start of cycle but fairly good skill in forecasting next 6 to 9 fairly good skill in forecasting next 6 to 9 months aheadmonths ahead
-Monitoring with satellites-Monitoring with satellites-Buoys measure sea surface temps, waves, -Buoys measure sea surface temps, waves, winds, and ocean currents winds, and ocean currents -Reports from ships at sea-Reports from ships at sea
South Pacific GyreSouth Pacific Gyre
El NinoEl Nino
Global SST Departures (Global SST Departures (ooC) C)
Equatorial SSTs remained below-average in the central and east-central Pacific Ocean, and above-average in the western Pacific, Atlantic and central Indian Ocean. Positive anomalies covered much of the North Atlantic and western North Pacific Oceans.
Central & Eastern Pacific Upper-Central & Eastern Pacific Upper-Ocean (0-300 m) Weekly Heat Ocean (0-300 m) Weekly Heat Content AnomaliesContent Anomalies
January 2007 to April 2008: below average
May 2008 to mid-August 2008: above average
Mid-August 2008 to Current: below-average
El Nino Oscillation since 1950El Nino Oscillation since 1950
The most recent ONI value (July– September 2008) is 0.0oC.
El Niño
La Niña
neutral
1997-1998 El Nino1997-1998 El NinoStrongest on record, developing more rapidly Strongest on record, developing more rapidly than any other El Nino in past 40 years.than any other El Nino in past 40 years.
July 1997: record high sea-surface temps in July 1997: record high sea-surface temps in the Pacific Ocean.the Pacific Ocean.
Fall 1997: record flooding in Chile, Marlin Fall 1997: record flooding in Chile, Marlin caught off coast of Washington, extensive caught off coast of Washington, extensive smog cloud over Indonesia, quiet Atlantic smog cloud over Indonesia, quiet Atlantic hurricane season. hurricane season.
Winter 1997-98: heavy rains southern US, Winter 1997-98: heavy rains southern US, unusually mild Midwest winter, record rains in unusually mild Midwest winter, record rains in California and Florida.California and Florida.
Hurricane KatrinaHurricane Katrina
Tropical Connections?Tropical Connections?
Historically…Historically…
El Nino yields less tropical activity in the El Nino yields less tropical activity in the Atlantic and more in the Pacific.Atlantic and more in the Pacific.
La Nina yields more tropical activity in La Nina yields more tropical activity in the Atlantic and more in the Pacific.the Atlantic and more in the Pacific.
Funnel Cloud Over AustinFunnel Cloud Over Austin
Forecasts indicate NEUTRAL conditions will continue through Northern Hemisphere Summer 2009. Several dynamical models suggest weak La Niña conditions during the Winter of 2008-09
El NiEl Niño ño OutlookOutlook
Figure provided by the International Research Institute (IRI) for Climate and Society (updated 24 October 2008).
SST Outlook: NCEP CFS SST Outlook: NCEP CFS Forecast Issued 26 October Forecast Issued 26 October 20082008
The CFS ensemble mean (heavy blue line) indicates La Niña conditions through mid-2009.
U. S. Seasonal OutlooksU. S. Seasonal OutlooksNovember 2008 – January 2009November 2008 – January 2009
Temperature Precipitation
These seasonal outlooks combine long-term trends and soil moisture effects.
For More InformationFor More Information
http://news8austin.com/weatherhttp://news8austin.com/weather
http://weather.govhttp://weather.gov
Thank you!Thank you!
Burton FitzsimmonsBurton FitzsimmonsChief MeteorologistChief Meteorologist
www.news8austin.com/weatherwww.news8austin.com/weather