Many people do not know that in the chromatic variety that we perceive during the autumn, chemistry has a remarkable influence. We have all noticed, that especially at the time of year, the leaves of the trees change their color to brown, yellow or purple tones.
This occurs because in the autumn season there is a decrease in solar radiation, and consequently, the leaves of the trees produce less chlorophyll which is a dominant substance, and this situation causes the colors of other pigments found in the leaves, emerge to the surface of it.
We can say that the coloring of the leaves is the result of the competition that exists between chlorophyll and other pigments, and in seasons such as spring and summer because there is more solar radiation, chlorophyll is imposed on the others and that's why the leaves are greener.
Pigments responsible for the chromatic variety of the leaves in autumn
Each plant is capable of producing a series of pigments, which will depend on the genetic load that this plant possesses. That is why, according to their plant species, the plant can produce flavones, which are the origin of the pale yellow or white colors of the leaves, tannins provide a brown color, another type of pigment is carotene, responsible for the Red, orange and yellow colorations can also produce betalains that generate purple leaves.
There are other types of plants, which depending on the intensity of the activity you have had during the summer, can synthesize pigments such as anthocyanins, and this makes the pink, blue and purple colorations emerge on the surface of the leaves. Being an ideal condition to enjoy all this chromatic variety, that the autumns are dry and not very cold.
The sunsets turn redder in the autumn
During this season of the year, at dusk, when the sun is located at a lower altitude, very close to the horizon, the skies become redder, this is because the sun's rays must travel a greater distance within the atmosphere.
This situation, together with the fact that in autumn there is more wind, makes the red component of light the one that reaches the eyes of people, while colors such as blue, yellow and green, are dispersed in the air when approaching more to the violet color.
Those responsible for this color dispersion are the gases that make up the atmosphere and the solid particles (dust) that have been suspended in it due to the blizzards that are formed by the characteristic autumn winds.
This type of dispersion is known as Rayleigh scattering , in honor of Lord Rayleigh, who in the 19th century, found an explanation for the beauty of the reddish autumnal sunsets, as well as for the blue color of the sky, which originates from cause of the dispersion of molecules in the atmosphere at a shorter wavelength, which is located at the blue end of the visible spectrum.
