Mom, why is the sky blue? Mom, Why is the sunset red? Mom, why does it always looks better in the Eastern Sierra? Answers to questions you May have always wanted to know
Man is not the only one who can produce beautiful fireworks. Nature does a pretty fine job herself! Lake Crowley sunset.
Many people stop to admire a bright blue sky or a gorgeous red sunset. Few however, stay in one place to watch the evolution from blue sky to red sunset. I have been blessed over the last few years to experience and photograph that evolution several times. The last being Mono Lake a few weeks ago.
When people look at my sunrise or sunset pictures they tend to asked me how I can predict when the clouds are going to turn orange or red way, way before it happens. So I thought I would explain why the sky looks blue in the day and red at night. I will use my images to illustrate what it looks like, and then tell you my secret for predicting. Were friend so I no you will keep your promise not to tell anyone else. Right?
Spoiler alert. If you think that understanding the “physics” of sunrise/sunset light will take the romance of a beautiful sunrise/sunset away; just enjoy the pictures and skip the text except the last paragraphs.
The sun produces a full spectrum of color ROYGBIV. Have some fun and take as second to figure out what ROYGBIV stands for. The answer is at the end of the post. So if the sun sends out the full spectrum why do we see only part of the spectrum at different times of the day.
- First, our eyes see certain colors like blue or red better than others like violet.
- Second, the colors coming from the sun are determined by a phenomenon called scattering.
- Third, our atmosphere actually bends the sun's light toward the earth when it is low on the horizon.
Cool fact; when we are watching the sun set on the horizon the sun has actually sunk below the horizon. That was news to me and I will explain why later in the post.
Are you really looking at the sun or just the image that refraction has created?
Scattering affects the color of light coming from the sky, but what we see is determined by the wavelength of the light, the amount of atmosphere the light travels through, and the size of the particles in the atmosphere. The short-wavelength blue and violet are scattered by molecules in the air much more than other colors of the spectrum. This is why blue and violet light reaches our eyes from all directions on a clear day. But because we can't see violet very well, the sky appears blue. When the sun is above us it goes through less atmosphere and the blue and violet portions of the spectrum can get through without being totally dispersed.
When the sun is low on the horizon, sunlight has to pass through more atmosphere than during the day. More atmosphere means more molecules to scatter the violet and blue light before it gets to your eyes. The other colors with a longer wavelength continue on their way to your eyes. That is why sunrise/sunsets are often yellow, orange, and red.
Clouds during the late afternoon at Lake Tenaya, Yosemite
Entering the evening "golden" hour things start to warm up at Lake Tenaya, Yosemite
a bit after the sunset the fireworks really go boom!
With the sunlight moving through more of the atmosphere, the atmosphere actually bends the light toward the earth because of refraction. By time you see a sun on the horizon it has already technically set, it’s only due to the fact that the atmosphere bends light that you're are still seeing it. The blue and violet spectrum range bends quicker so we see the yellow, orange, and red lights longer. With a refraction of about 0.6° the apparent sun (what we see) is slightly more than a diameter above the actual sun's position. Blows your mind doesn't it.
The fuse is lit just after sunset at Mono Lake?
Clouds start warming up after sunset. Now just wait for it, wait for it...
Boom the clouds go nuclear almost a half hour after sunset!
Back to the question people ask on how to predict when the clouds are going to go nuclear orange/red. If the clouds are high in the sky and the sunlight from the horizon is not obstructed by the clouds there is a pretty good chance the clouds are going to go nuclear. The clouds really don't turn nuclear until well after the sun has set. Sometimes a good 15 minutes to a half hour after the sun is set. By the way ROYGBIV stands for Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Betcha Indigo threw you for a loop didn't it!
So when you see high clouds in the afternoon but they are not obstructing the horizon that would be a great time to head out to the South Tufas on Mono Lake, the shore of Crowley, the Whoa-Nellie Deli, the Mono Inn, or heck just about anyplace!
For the full story on the physics of sunrise and sunset colors, with diagrams, check this site out:
http://scienceblogs.com/startswithabang/2013/02/13/the-physics-of-sunsets/
#Yosemite, #Clouds, #Sunset, #Sunrise, #Eastern Sierra, #Mono County, #Mono Lake, #Tenaya Lake, #Light, #Blue Sky, #Red Sunset