El Nino and La Nina

[Element92]

I'm doing an AS level in Geography.  Can anybody help please with a simplified version of what El Nino and La Nina are, how they are important, and how they affect short term climate change. Many thanks.

[BornFromTheVoid]

Hi Element92.

 

El Nino and La Nino are part of the El Nino Southern Oscillation (ENSO). El Nino is the warm phase, which is characterised by warmer than normal sea surface temperatures in the tropical Pacific, while La Nina is the cool phase, with colder than normal sea surface temperatures in the tropical Pacific. The "Southern Oscillation" part is the change in air pressure over the tropical Pacific associated with ENSO.

 

Beyond that, getting scientific answers on a public forum has a lot of risks. You'll find conflicting opinions, brilliant and intelligent sounding answers about the effects of ENSO, that in reality, are absolute nonsense.

 

What I'd recommend, is sticking to the main weather and climate related scientific organisations, their guides, videos and information. Organisations like NASA, NOAA, ESA, BOM, Met Office and the like. Some university websites will have good guides also.

 

This might be somewhere to start http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/

At the bottom left of the page (under outreach) is section with FAQs, tutorials and more.

 

Here's the Met Office guide http://www.metoffice.gov.uk/research/climate/seasonal-to-decadal/gpc-outlooks/el-nino-la-nina/enso-description

 

Two more links

http://www.ucar.edu/communications/factsheets/elnino/

http://www.nc-climate.ncsu.edu/climate/patterns/ENSO.html

 

 

If you find yourself stuck or struggling to understand anything, then perhaps someone around the forum might be able to help you out

[Element92]

Hi BornFromTheVoid and many thanks for your excellent reply. It's actually my son who is doing his A level exams, and he says he'll visits the sites you mention tomorrow. He loves anything to do with the weather, would like to work in some climate/weather field and thanks you very much.

 

Kind regards

Andy

[knocker]

Probably of no interest but I posted something on the background of this a wee while ago.

 

http://forum.netweather.tv/topic/64228-when-the-monsoon-failed/

[pottyprof]

Another couple of links.

El Nino - http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html

La Nina - http://www.pmel.noaa.gov/tao/elnino/la-nina-story.html

There is also some very good information in Netweather's learner's area/guides.

http://forum.netweather.tv/forum/24-learning-about-weather-and-meteorology/

[Gray-Wolf]

We also seem to be moving away from calling 'neutral' neutral as it suggests little or no impact whereas impacts, though less predictable, can be just as wide reaching.

 

They seem to favour La Nada, when you cannot call Nino or Nina from the temp plots, and if climate change is impacting ENSO then more La Nada's may be a result?

[Methuselah]

Isn't it 'neutral' only in respect to temperature distribution, Ian?

[Gray-Wolf]

Correct Pete!  If it doesn't tick the boxes for Nino or Nina then we call it neutral but folk have realised that this means not a lack of influence but a wide range of influences either trending toward Nino like impacts or Nina like impacts.

 

If N.Hemisphere changes in atmospheric circulation are altering wind regimes across this part of the Pacific then we may see more 'Nada's' over the coming decades?