Meaning of Albedo


The first thing we are going to do in order to determine the meaning of the term albedo that we are dealing with now is to discover its etymological origin. In this case, we can say that it is a word that derives from Latin, specifically “albedo”, which can be translated as “whiteness”.

In the field of physics, the relationship between the light energy diffused by a surface through reflection and the incident energy is called albedo.

In other words, the albedo reveals what level of radiation a surface reflects compared to the total radiation it receives. The albedo, therefore, is indicated in percentage terms.

According to specialists, planet Earth has an average albedo of about 38% compared to solar radiation. On light surfaces, the albedo is higher than on darker surfaces.

While snow has an albedo of 86% (that is, it reflects 86% of the light it receives), deserts are around 21%, forests reach 8% and the seas barely reach 5% and 10%. This means that a snow-covered surface reflects much more light than an ocean.

When the albedo is high, the temperature on the planet tends to drop because the radiation from the sun, for the most part, is not absorbed, but reflected. On the other hand, if the albedo is low, the planet warms up: the percentage of solar radiation that absorbs the surface is very high.

A curiosity about this effect that we are addressing occurs in Andalusia. Specifically, in them, since time immemorial, it is traditional that the facades of the houses are painted white. And that is because, in this way, the albedo is high, thus being able to reflect light and regulate heat, especially in summer when temperatures are very high.

In other words, it is a way of ensuring that inside the Andalusian homes you can enjoy a little more freshness than on the street.

Other uses of the notion of albedo are found in botany (as a certain sector of the fruit mesocarp is called) and in alchemy (albedo is one of the stages of transmutation that allows a substance to be converted into gold).

Within the scope of gastronomy the term albedo is also used. In this case, when it is used it is to name the white and bitter part that certain citrus fruits have, such as oranges, lime or grapefruit. It is a part that, although it is generally discarded, has recently come to be considered as very useful for shaping all kinds of dishes, recipes and even drinks.

A good example of this can be found in a recipe by the internationally renowned and famous Catalan chef Ferrá Adriá. We are referring to the espardeñas with albedo puree.