The term “albedo” refers to the amount of solar energy that is reflected from the earth and returns to space.
Albedo is part of the energy of the sunlight that flows back into the atmosphere. These rays have a considerable influence on our climate. As the albedo rises, the universe reflects more light and consequently higher levels if radiation are sent back into space to cool the Earth. Albedo determines the heat volume on Earth. It is now known that most of the sun`s light moves upwards when it hits the earth. Studies have shown that water absorbs more light and this reflects less lights. If there is more water compared to a hard surface, there is less solar radiation. The earth, moon or other planet has the ability to transfer albedo.
What is Albedo?
Albedo can be defined as wa way to quantify how much radiation is reflected from the surface. It is a comparison between the reflected radiation from the surface and the amount of radiation that hits it. This term also refers to the amount of radiation generated by electromagnetic radiation that is reflected.
Seasonal effects on Albedo.
Summer.
To better understand Albedo, we`ll look at two scenarios. First, if you walk barefoot on the black ground in summer, you will feel a lot of heat and can even be burned because the surface absorbs and stores more heat. Another person running on a white surface at the same time will not be burned. This is mainly because the white surface tends to reflect more heat and absorb very little of it. Similarly, if you touch a black car in summer, it will feel much hotter than touching a white car. This is because black absorbs and stores heat while the white car surface reflects back the sun`s rays.
Winter.
During this season it is usually wet either by rain or snow. Water reflects about 6% of the light and absorbs the rest. Ice, on the other hand, reflects 50% to 60% of the incident solar heat and stays cooler. As snow-covered area reflects a lot of radiation, which is why skiers on the slopes are at risk of sunburn. Albedo decreases when the snow-covered areas warm up.
How is Albedo quantified?
Albedo helps us to know how well a surface reflects solar energy. It is measured on a scale from zero to one (0-1). The surface differ in their absorbency, but are always in the range of 0 to 1.
Value “0” – If a value of zero is given, then the conclusion is that the surface is very light sensitive, meaning that the surface absorbs all the light that comes into contact with it. It is characterized by black surfaces.
Value “1” – This value is proof that the surface does not absorb the incident light. It is characterized by white surfaces.
The albedo of our planet is 0.367, while that of the Moon is 0.12, which means that the Moon reflects 12% of the radiation it receives. There are many satellites that monitor the albedo of the planet using sensors that measure the light of the Earth reflected on the lunar surface. NASA has developed Terra and Aqua satellites to hep identify changes in Albedo.
Various studies.
The studies by Andre-Louis Danjon (1928 – 1954)
Andre Louis Danjon, a Frenchman, conducted studies on Albedo. He used an approach he is known as “The eyes of a cat”. He used light to create a bio-image of the moon, which made it possible to check the similarity and differences in degrees between two research samples of the moon`s surfaces. With this approach, he adjusted some light from the part with sunlight to correspond to the sunlight of the other side.
The research work led to the so-called Danjon scale astrolabe, which also led to an improved accuracy of the large visual astrometry. In adition, he developed a five-point measurement parameter to assess the visual appearance and brightness of the moon during a total solar eclipse. He used the letter “L” to indicate the high darkness.
L-0: The moon can`t be seen. This is characterized by the total thickness up to the mean attenuation.
L-1: The details are visible, but with some difficulties.
L-2: The shadows in the middle are very weak, but the outer edge is a bit bright.
L-3: The umbilical shadow has a yellow color around it.
L-4: There is a blue-looking, shiny color around the moon. It has either red or orange tones. It emits a lot of light.
Albedo Variations of the Earth`s Surface 1998-2014.
These were the second studies carried out within a total of sixteen years. During this time, humans tried to understand the relationsship between the Earth`s lustre and moonlight. This was evaluated both by the air satellites and on the ground over a period of sixteen years. The moon was the focus of the study.
De Pater and Lissauer Table by Albedo.
De Pater and Lissauer categorized Albedo into two groups, Geometric and Bond Albedo, i.e. the amount of radiation compared to the frequency repeated in wave form, while Bond Albedo emphasized the total radiation reflected by an object compared to the total incident radiation of the solar planets.
Albedo driver.
Factors that drive Albedo are:
The albedo effect and the warming of the universe.
It has been found that the global albedo has increased recently and on a measurement scale the watts per square meter is now larger. This is the result of research by Anthony Watts.
The universe is gradually getting hotter die to deforestation. Better forestry skills should be encouraged to mitigate the effects of albedo. Trees reduce the radioactive effects of solar reflection. In this context, the melting of ice in Antarctica is a major concern.
Many countries are in favour of resuming forestry as trees are darker and albedo emission rates have been reduced. If you plant several trees, you will be paid according to a system called Carbon Credit. The clouds can sometimes reflect sunlight, but can still store heat and warm the earth.
Today, climate scientists and researchers are concerned that if global warming continues, the polar ice caps will melt and seawater will absorb more sunlight, increasing global warming. In this context, we should all work towards developing better models to limit their impact in the future.
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