A Word on the Solstice - Effect of Earth's Revolution and Tilt

Well, for those of us who live within the northern hemisphere, summer is long last here. This past weekend, on June 21, 2014, marked the official start of summer.  This day is also known as the Summer Solstice. I am from New York but my wife and I had the most fortunate opportunity of spending this Summer Solstice in Huntington Beach and Newport Beach in Southern California .  During the day we spent our time under the Sun along the pier in Huntington Beach.  One of the main landmarks of Huntington Beach, also known as "Surf City, USA", the pier is the center of the city's prominent beach culture.  I had breakfast at Ruby's Dinner at the pier's end. All the surfers were out on the water and there was volleyball competitions and live music along the beach.  In the evening, we enjoyed our sunset along the waterfront of Newport Beach at the Rusty Pelican. It was truly a delightful Summer Solstice.

However, besides spending great moments at the beach, and having endless ocean waves crashing along the shore, what is the significance of the summer solstice?  Let us look at this special event with a keener scientific point of view.  The effects of Earth's revolution include the seasons and variations in the length of days and nights. In addition to its revolution, the tilt of the Earth's axis has a profound effect on Earth.  At almost any given time, one hemisphere is tilted toward the Sun, as the other is tilted away.  The hemisphere tilted toward the Sun receives more direct sunlight and thus has warmer temperatures and longer daylight hours. The hemisphere tilted away from the sun receives indirect sunlight and thus cooler temperatures and less daylight hours (longer nights).


The Northern Hemisphere is tilted toward the Sun marking the Summer season for this part of the Earth.  Southern Hemisphere is tilted away from the Sun marking the Winter for this region of the Earth.
The first day of summer in the northern hemisphere occurs on or about June 21 each year. Coincidentally, it is also the first day of winter in the southern hemisphere.  This day has the longest daylight period for the northern hemisphere and the shortest daylight period for the southern hemisphere.  In the northern hemisphere, the sun's apparent path in the sky is longer and higher than at any other time of year.  In the southern hemisphere, the sun's apparent path is shorter and lower than at any other time of year.  The point at which the Sun reaches the highest and lowest path across the sky, is the solstice.  The word solstice is derived from the Latin sol (sun) and sistere (to stand still), because at the solstice, the Sun stands still; that is, the apparent movement of the Sun's path across the sky comes to a stop before reversing direction. 


On the first day of Summer for the northern hemisphere, every point on Earth within 23.5° of the North Pole (Arctic Circle) experiences 24 hours of daylight.  Along the southern hemisphere, at that same period of time, every point within 23.5° of the South Pole (Antarctic Circle), experiences 24 hours of night.

So all of you within the northern hemisphere, enjoy your summer. For in a short six months, the solstice will once again occur. Only this time, it will be winter.

Comments

Popular posts from this blog

Rock Cycle

Weather Map Project

The Transportation of Weathered Materials