Friday, March 20, 2015

Vernal Equinox 2015

Happy Vernal Equinox!

Today at 6:45PM (EST) the seasons switch from Winter to Spring.  The date that this switch occurs is known as the Vernal Equinox.

On this date, the sun appears to cross the equator from the southern sky to the northern sky.  The sun does not really cross the equator, but a tilt in the Earth's axis means that the sun does not strike the globe evenly.  During the Northern Winter, the North Pole points away from the sun by an angle of 23.5 degrees while the South Pole points toward the sun an equal number of degrees.  This ensures that during our northern winter we get much less sunlight during a day than the southern hemisphere does during the same period (their summer).  During our Northern Summer, the northern hemisphere is angled toward the sun so we receive more hours of sunlight that the southern hemisphere does during the same period (their winter).

On the Equinox, poles are essentially perpendicular to the rays of the sun so locations in the northern and southern hemispheres receive equal hours of sunlight and darkness.  Mt. Pleasant is located at 43 degrees 36 minutes north of the equator.  On the equinox, it experiences 12 hours 8 minutes worth of daylight.  A location located at 43 degrees 36 minutes south of the equator will receive approximately the same length of daylight.  The hours of daylight that Mt. Pleasant Experiences will grow until it reaches 15 hours 26 minutes around the Summer Solstice.  Then our hours of sunlight will diminish until on the Winter Solstice we experience only 8 hours 56 minutes of daylight, before increasing again.

To learn more about the changing of the seasons please look at my Vernal Equinox posts from 2013 and 2014.

Here is photo to get you in the mood for Spring.

A small metallic green bee on Bloodroot (Sanguinaria canadensis) - April 2014

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