Tuesday, September 4, 2012

El Nino versus La Nina


As I write this article, South Dakota has dozens of schools closing early because, once again, our temperatures are getting awfully close to 100 degrees.  It has been a HOT, dry summer and I think we’re all eager for it to be over.  But WHY has it been so hot and dry?

I’ve heard the words El Nino (‘The Boy’ in Spanish) and La Nina (‘The Girl’) tossed around a lot over the years and I always knew it had something to do with the water in the Pacific Ocean, but I never really paid attention to the specifics or why it would have any effect on us up here in the Midwest.  So here’s a very simple crash course.  And I say simple because half of the things I researched, I don’t think anyone could understand without an oceanography degree.

El Nino is the one that is responsible for hotter, drier summers around these parts.  El Nino begins when the trade winds weaken and a series of Kelvin waves (shallow, but very wide) travel across the Pacific and create a large pool of warm water near South America.  Normally, the water along South America is cold from upwelling, bringing the nutrients up from the seafloor and leading to great fishing.  During El Nino, that water warms up and creates all sorts of problems.  The Pacific Ocean is a heat sink, meaning its water is warmer than the Atlantic and since it covers so much of the surface of the earth, when its temperature changes, the weather all over the world changes with it.

La Nina is the opposite of El Nino.  More cold water is in evidence off the coast of South America and the trade winds blow more strongly than normal.  During La Nina times, more precipitation is recorded in the Midwestern states – heavier winters and more rainfall. 

Pipestone County Star

The cycle for these events averages to about every five years.  When El Nino or La Nina last for less than nine months, they are referred to as “conditions.”  If they last for more than nine months, they are referred to as “periods.”  Our last La Nina was 2011, which was probably part of the reason we had a very wet year.  This year, not so much… During the summer, meteorologists stated there’s a 50% chance of El Nino taking hold.

Please keep in mind, this was a very simple explanation.  There are many more factors to take into account for both El Nino and La Nina.  If you are interested, I encourage you to go online and read more about these weather patterns – then come and explain it more to me!

A tiny bit of trivia: During non-El Nino conditions, the trade winds move from the east to the west, pushing the warm water towards the South Pacific islands.  This aids in the upwelling I mentioned earlier along South America and actually means that the Pacific Ocean is 60 centimeters higher on the west side. 

Ebooks!! Ebooks have now gone live and you can check out a book to your Nook, Kindle, or other Ereading device.  If you have trouble accessing Overdrive through the Meinders Library catalogue, please call the library and let us know!!

PAFL Update:  Pipestone Area Friends of the Library is looking for members – anyone who is a friend to Meinders Library is welcome to join!  The Friends group works hard to promote the library, raise money for projects, and organize their yearly book sale, in addition to the HUGE amount of support they provide throughout the year.  For more information, please contact the library!

Book Club Reminder:  Book Club will be meeting September 27th at 7:00 PM in the Meinders Library Conference room.  The book this month is Devil in the White City by Erik Larson.  Please contact the library for a copy and feel free to join up with our readers!  Everyone is welcome!

If you have questions or have a book you’d like to reserve or renew, please don’t hesitate to give us a call at (507) 825-6714.  The hours for Meinders Library are Monday through Thursday from 10 AM – 8 PM, and Friday and Saturday from 10 AM – 5 PM.   Meinders Community Library is located at 1401 7th Street SW, on the south side of the high school.


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