The Reasons for the Seasons

While doing some lite browsing online looking for articles to help me better understand the topics we covered in class this week, I found one in particular that I thought was really good and wanted to share.  The article is called Learn the Scientific Reasons Behind Earth's Seasons.  I found this article on msnbc.com.  This article has some great information about solstices and equinoxes, the effects on climate, the tilt of Earth, and how it all relates to our seasons.  The website also has some interesting images that I will share later in the post.  Below is a brief summary of what I think are the most interesting points of the article. I will provide the web address at the bottom so you can check it out for yourself.

Have you ever stopped and thought about how much the seasons really effect us?  I never did until I started taking this astrology class for school.  Seasons effect our food production and availability, our mood, our fashion, the food we crave, and the activities we do in our daily life.  Because they have such an impact on us, I feel it is important that we have a good understanding of the reasons for our seasons. Way back, Babylonians and Mayans would track the rising and setting points of the sun to predict the seasons.  Then, between 1473 and 1543 our world was rocked (for lack of better words) when Nicolai Copernicus discovered that the sun, instead of Earth, was the center of the solar system.  From this, we learned that Earth orbits the sun in a circle and at the same time, spins on its axis.  "Because the sun is our source for light, energy and heat, the changing intensity and concentration of its rays give rise to the seasons of winter, spring, summer, and fall".  Solstices and equinoxes help mark our seasons.  Solstices occur each year around June 21 and December 21 and are when the poles are tilted at their max, either toward or away from the sun.  This is when we have the start of summer and the start of winter.  During the June solstice the North pole is tilted toward the sun which means the northern hemisphere is enjoying summer.  Because Earth is on a tilt and the north is pointed toward the sun, this means that the South Pole is away from the sun and the southern hemisphere is experiencing winter.  On the other hand, equinoxes are when the sun is directly over the Earth's equator.  The vernal and autumnal equinox represent the beginning of spring and fall.  "At these times, the sun is directly over the equator and the lengths of day and night are equal over most of the planet...on March 21 the Northern Hemisphere reaches the vernal equinox and enjoys spring.  At the same time, the winds turn colder in the Southern Hemisphere as the autumnal equinox sets in".  In all of this it is very important to remember that these dates are not concrete.  Because of the Earth's changing tilt matching up to its orbit around the sun, the date may be off by a couple hours or a couple days. 

Here are some of the pictures from the article to help better understand our seasons....
 


NASA / EUMETSAT

"These views of Earth from the Spinning Enhanced Visible and Infrared Imager on EUMETSAT's Meteosat-9 satellite shows the terminator line on Dec. 21, 2010 (upper left), March 20, 2011 (upper right), June 21, 2011 (lower left) and Sept. 20, 2010 (lower right). The sequence illustrates how Earth's northern half receives more sunlight in June, while the southern half gets more light in December"

Check the article out for yourself.... http://www.nbcnews.com/id/3077384/ns/technology_and_science-science/t/learn-scientific-reasons-behind-earths-seasons/