Changing Leaves

Pipestone County Star, 09-27-12

I love fall.  It’s my favorite time of year.  The crisp air, the fact that I can wear my favorite yellow jacket, and the pumpkin flavoring that gets put in everything all combine to make me one very happy librarian.  I’ve always loved to look at leaves, but I’ve never given much thought to how they change color.  This year, I thought I would check into it.

Plants use sunlight to make oxygen and sugar from water and carbon dioxide.  They use a chemical called chlorophyll to accomplish this process.  Chlorophyll happens to be green, which is why leaves are green throughout the spring and summer.  In the fall, when the leaves begin to turn, the chlorophyll is going away and the trees are no longer making food.  As trees go dormant, their leaves change colors.

The beautiful red that is my favorite is caused by the leftover glucose turning color in the sunlight.  The brown of oak leaves is the result of waste products left behind from photosynthesis (turning sunlight into food) in the leaves.  Purples and yellows are caused by other chemicals and pigments left behind in the leaves as the chlorophyll fades away.

Weather also has an effect on leaf color.  If the weather is cool, more colors will form, but freezing will dull them.  This would be why we have brilliant colors for only a short period around here – it doesn’t take long to go from cool to freezing in Minnesota.  The best time to enjoy leaves is late September to early October, when the weather is clear and cool, but we haven’t (hopefully) had any frost yet.

As the leaves change color, the trees also get ready to lose them.  Small groups of cells form at the base of each leaf and gradually separate them from the tree, sealing the bark behind them.  When the leaf gets blown away or falls because it’s too heavy, it leaves behind a tiny leaf scar, already healed by the tree.

Go out and enjoy the leaves this year – hopefully they will be beautiful!  Happy fall, everyone!!

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 27^th 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.  (The Saturday of Labor Day Weekend, the library is only open from 10 until Noon).  Meinders Community Library is located at 1401 7^th Street SW, on the south side of the high school.

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 27^th 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 7^th Street SW, on the south side of the high school.