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How does a rainbow form?  Why is it going to rain tomorrow?  What historic hurricane hit this time last year?  Check our blog for content articles unique to Campus Connect.  Our students are dedicated to providing you with fun weather facts and forecast descriptions.  Want to learn about something new?  Send a comment our way and let us know!

What’s that term, Virga?

Posted by on Nov 10, 2015 in Blog | 0 comments

Have you ever read or hear the term “Virga”? Maybe you have looked at radar seeing shades of light green, but there is no rain? “Virga” meaning “branch” or “twig” in Latin is precipitation falling from clouds and evaporating before it hits the surface. Cool right? Virga often looks like streaks in the sky or shafts under a cloud base. Virga can happen when low humidity and high temperatures make precipitation evaporate before it hits the surface.

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This process mainly takes place in Canada, the Middle East, Australia, at high altitudes, and in desert areas around the globe. You can also catch a glimpse of virga in western parts of the United States where clouds produce lightning, thunder, and no measurable rainfall at the surface. In the winter, virga can happen when rain or light snow is spotted in the sky and the surface is drier than aloft. It can also happen before a microburst thunderstorm.  Virga is pretty rare in the southeast so if you happen to catch a glimpse of the awesome streaks in the sky – make sure to take a photo. ~Meagan Massey

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Photo 1 Citation:

Jensen, Susan. Virga in Washington. 2015. EarthSky. Web. <http://earthsky.org/earth/virga-is-rain-that-doesnt-reach-the-ground>.

Photo 2 Citation:

Ratliff, Ron. Virga in Utah. 2015. Mexican Hat. EarthSky. Web. <http://earthsky.org/earth/virga-is-rain-that-doesnt-reach-the-ground>.

 

Painting the Sky: The Northern Lights

Posted by on Nov 6, 2015 in Blog | 0 comments

The Northern Lights are a natural phenomenon that occurs at high latitudes around the Earth’s poles, however earlier this week the beautiful light show was on display in parts of the United States. This is an extremely rare occurrence for us in the continental United States, but portions of the Northeast and Midwest were able to experience this magnificent event Monday and Tuesday nights. The lights were driven south to lower latitudes all due to mass solar eruptions that triggered a geomagnetic storm. With the timeliness of this spectacular event, what better topic to explore in this week’s blog than the Northern Lights! 

What are the Northern Lights?

This mystifying natural phenomenon is also known as Aurora Borealis. The Northern Lights mainly occurs at the poles in both the Northern and Southern hemispheres. Collisions between electrically charged particles cause the sky to illuminate in an array of colors. The lights can extend 50 to 400 miles above the surface and take many forms, such as scattered clouds of light, arcs, or shooting rays.

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Image Credit: NASA Aurora Image Gallery https://www.nasa.gov/mission_pages/sunearth/aurora-image-gallery/index.html

What Causes this Phenomenon?

The basic explanation for the Northern Lights is the collision between particles in the atmosphere and particles from the sun, but lets dive into a little more detail. This process originates 93 million miles away, when storms on the sun cause gusts of charged solar particles to be released into space. These particles are blown towards Earth by the solar winds and are mainly deflected by the Earth’s magnetic field. Keep in mind, the magnetic field is weaker at the poles, so at this location some particles are able to enter the Earth’s atmosphere. The positive charged particles (electrons) from the sun collide with gaseous particles within the upper level of the atmosphere, causing the particles to become ‘excited’.  Finally, as the molecules return to their original state, they emit photons, or small bursts of energy in the form of light.

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Image Credit: EarthSky via NASA

What Causes Different Colors?

Variations in color are due to the type of gas particles, Oxygen or Nitrogen, that collide with the particles from the sun as well as the altitude at which they collide. The most common auroral color is green and is produced when oxygen molecules collide with electrons about 60 miles above the surface. More rare, all red auroras are produced by high altitude oxygen molecules 200 miles above the Earth’s surface. Finally, when Nitrogen collides with the electrons, it produces light that has a blue or purple coloring.

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Image Credit: NASA Aurora Image Gallery

https://www.nasa.gov/mission_pages/sunearth/aurora-image-gallery/index.html

When and Where Can You See the Northern Lights?

 The Northern Lights typically occur in a ring shaped area, known as the auroral ovals, around the magnetic poles. A few of the best places to view the lights are in central Alaska, Canada, Greenland, and northern Russia. Although auroral activity can occur day or night, the light is much dimmer than sunlight making it virtually impossible to see during the daytime. The best displays take place when it is dark, specifically a few hours before midnight. It’s also easier to see the Northern Lights in the winter due to the long periods of darkness and high frequency of clear nights.

~Kelly Scott

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Citations:

 “Aurora.” nasa.gov. NASA, n.d. Web. 5 Nov. 2015.             <http://pwg.gsfc.nasa.gov/polar/EPO/auroral_poster/aurora_all.pdf>.

 “Aurora Image Gallery.” nasa.gov. NASA, n.d. Web. 05 Nov. 2015.     <https://www.nasa.gov/mission_pages/sunearth/aurora-image-gallery/index.html>.

 “What Causes the Aurora Borealis or Northern Lights? | EarthSky.org.” EarthSky. N.p., 30 Jan. 2015. Web. 05 Nov. 2015.<http://earthsky.org/earth/what-causes-the-aurora-borealis-or- northern-lights>.

Scattering 101

Posted by on Nov 2, 2015 in Blog | 0 comments

The Colorful Atmosphere

As a lover of all things weather, one weather phenomenon in particular (that I love) are the clouds and beautiful blue skies that we see here in Mississippi on clear, calm days. Many people may wonder why the sky is blue. Why not, red, or green? It is a simple, yet complex idea dealing with a term called scattering. Keep in mind that the human eye can only see a small portion of what the sun is giving off from the electromagnetic spectrum. Our eyes can only see the visual part of that spectrum and with that comes different wavelengths represented by a multitude of colors. When the sun comes up every morning, the incoming solar radiation is in reach with Earth’s atmosphere, it is scattered in all different directions. Blue wavelengths are scattered much more efficiently and they are shorter which is why the sky looks blue.

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Science Made Simple. Digital image. N.p., n.d. Web. 29 Oct. 2015. <Http://www.sciencemadesimple.com/img_sky/horiz.jpg>.

Now there are two terms to define more specifically that help to explain why the sky is blue and why the clouds are white; Rayleigh scattering and Mie scattering. As discussed earlier, the sky appears blue because of the sunlight that is reflected off of different molecules. Rayleigh scattering better defines this idea because the scattering of light off of the molecules of the air gives us the blue sky. For Mie scattering, it does not necessarily depend upon the wavelength but it gives off the white glare that we see around the sun when a lot of particles are in the air. Rayleigh scattering is the more dominant of the two because of its favor towards shorter wavelengths. The water droplets that make up the cloud are much larger than the parcels in the air and they do not depend on wavelength, so they are overshadowed by the blue wavelength leaving them with a white-grayish tint.

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The Natural Environment. Digital image. N.p., n.d. Web. 29 Oct. 2015. <https://laulima.hawaii.edu/access/content/group/2c084cc1-8f08-442b-80e8-ed89faa22c33/book/chapter_2/scatter.htm>.

Sunrise & Sunset

For sunrises and sunsets, this concept is a little different. Starkville is known for its beautiful sunsets and sunrises, almost everyone has either put a picture on Twitter or Instagram of the sun setting. As the sun lowers in the sky, the atmosphere at that  becomes much thicker and these wavelengths have to scatter through it. Shorter wavelengths have a harder time doing that, so longer wavelengths can penetrate through. Blue and violet wavelengths are scattered back into space due to their shorter wavelengths, while red and orange wavelengths make it through the thicker layer making the sky beautiful. Smog and ash can also enhance the coloring of the sunset and sunrises. The atmosphere has a unique way of working and the science behind it makes it more intriguing that what the human eye can only see.  ~Caroline Ritter

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Photo taken by Caroline Ritter on October 24, 2015 during the Run For Wishes 5k put on by Chi Omega at Mississippi State University