October Column as published in the Woburn Advocate
A few weeks ago I happened to be driving down Arlington Road at about quarter past six in the evening. I pulled into the Clapp School parking lot as the sky looked promising for a nice sunset display. I spent almost an hour down on the sand at the bottom of the steps across from said parking lot, and I was not alone! There ended up being 6-10 people between here and up at the benches on the street. Most were taking photos with their cell phones, but at least three of us down on the shore had real cameras. And I was right! It turned into a gorgeous display of color and clouds! The best I had seen all summer at Horn Pond! I’ll be the first to admit, we haven’t had much in the way of striking sunsets this summer. But fall is coming and that seems to be a good time of year for sunsets. I’m hoping for some good color in the sky as well as in the foliage!
What makes a sunset special? Is it the clouds? That day at Horn Pond there were amazing clouds that just lit up. But earlier in the month I witnessed a sunset on a beach on Cape Cod that was completely cloudless, but none the less spectacular. The color was so intense, there was a corona of deeper color arching over the sun as it set, turning the waves into liquid fire!
What exactly is the anatomy of a sunset? What makes a sunset vivid to the human eye? A lot of people think that particles in the air like dust or water vapor intensify the colors. Actually, it is just the opposite. Clear, clean air in the lower atmosphere is what gives us those great colors! It all has to do with the scattering of light by air particles and the angle at which we are viewing it. That’s why when the sun is overhead, the sky appears blue, but when we are looking at the light coming sideways at us from the horizon (traveling a longer distance), more of the violet and blue light is scattered so more of the yellow, orange and red light is visible to us as the sun sinks in the sky. The more particles like dust, pollution or moisture (think high humidity), the less the light is scattered, so the more subdued the colors.
This explains why we tend to get better sunsets (and sunrises for those who are actually up to see it) in the fall and winter when the air is clearer or after a storm when the air has cleared as the front moves out. Think about that old adage that says “Red sky in the morning, sailors take warning, red sky at night, sailors delight”. Our weather tends to move west to east in the northern hemisphere so a storm front moving in in the morning would produce a red sunrise and a front moving out late in the day would leave behind a spectacular sunset! Think about the weather this past summer; hot and humid air results in dull sunsets. (Dull, pale skies in midday also, if you think about it). Places in the world with little air pollution like desserts, mountains or the tropics tend to have the best sunsets. Personally I think any place with water just makes a sunset even better!
This is a simplified explanation. The PHYSICS of light at twilight is much more complicated. Not only do you have to consider air particles and the angle and distance the light travels, but types of clouds in the sky at sunrise/set; are they low clouds or are they high clouds. Then there are fine particles from volcanos high in the Stratosphere that give amazing ‘afterglows’. But larger particles lower down act like haze and smog. It is a very complicated science. But what isn’t complicated at all is how one can enjoy one of these gorgeous spectacles of nature!!! Here’s wishing you beautiful sunrises and sunsets in the coming weeks.
To see more of Horn Pond’s best sunsets click on any season’s ‘Fire in the Sky’ galleries in this website.
If you wish a little more in-depth explanation you can go here to this website:: http://www.spc.noaa.gov/publications/corfidi/sunset/
What makes a sunset special? Is it the clouds? That day at Horn Pond there were amazing clouds that just lit up. But earlier in the month I witnessed a sunset on a beach on Cape Cod that was completely cloudless, but none the less spectacular. The color was so intense, there was a corona of deeper color arching over the sun as it set, turning the waves into liquid fire!
What exactly is the anatomy of a sunset? What makes a sunset vivid to the human eye? A lot of people think that particles in the air like dust or water vapor intensify the colors. Actually, it is just the opposite. Clear, clean air in the lower atmosphere is what gives us those great colors! It all has to do with the scattering of light by air particles and the angle at which we are viewing it. That’s why when the sun is overhead, the sky appears blue, but when we are looking at the light coming sideways at us from the horizon (traveling a longer distance), more of the violet and blue light is scattered so more of the yellow, orange and red light is visible to us as the sun sinks in the sky. The more particles like dust, pollution or moisture (think high humidity), the less the light is scattered, so the more subdued the colors.
This explains why we tend to get better sunsets (and sunrises for those who are actually up to see it) in the fall and winter when the air is clearer or after a storm when the air has cleared as the front moves out. Think about that old adage that says “Red sky in the morning, sailors take warning, red sky at night, sailors delight”. Our weather tends to move west to east in the northern hemisphere so a storm front moving in in the morning would produce a red sunrise and a front moving out late in the day would leave behind a spectacular sunset! Think about the weather this past summer; hot and humid air results in dull sunsets. (Dull, pale skies in midday also, if you think about it). Places in the world with little air pollution like desserts, mountains or the tropics tend to have the best sunsets. Personally I think any place with water just makes a sunset even better!
This is a simplified explanation. The PHYSICS of light at twilight is much more complicated. Not only do you have to consider air particles and the angle and distance the light travels, but types of clouds in the sky at sunrise/set; are they low clouds or are they high clouds. Then there are fine particles from volcanos high in the Stratosphere that give amazing ‘afterglows’. But larger particles lower down act like haze and smog. It is a very complicated science. But what isn’t complicated at all is how one can enjoy one of these gorgeous spectacles of nature!!! Here’s wishing you beautiful sunrises and sunsets in the coming weeks.
To see more of Horn Pond’s best sunsets click on any season’s ‘Fire in the Sky’ galleries in this website.
If you wish a little more in-depth explanation you can go here to this website:: http://www.spc.noaa.gov/publications/corfidi/sunset/