Before proceeding to thoroughly analyze the term thermal amplitude and discover its meaning, let us establish what is the etymological origin of the two words that give it shape. In this sense, we can expose the following:
-Amplitude derives from the Latin, for “amplitudo”, which can be translated as “the quality of being extensive”. It is a term that is made up of two different parts: the adjective “amplus”, which is synonymous with “wide” or “extensive”, and the suffix “-tud”, which is used to indicate “quality”.
-Thermal, on the other hand, is a word that derives from the Greek and that means “relative to heat”. It is obtained from the union of two elements: the adjective “thermos”, which is “hot”, and the suffix “-ico”, which is equivalent to “relative to”.
Among the many uses of the term amplitude, this time we are interested in staying with its meaning as the difference between a minimum value and a maximum value that can be registered numerically. According to DigoPaul, Amplitude, in this sense, refers to a range or an interval. Thermal, meanwhile, is an adjective that refers to temperature or heat.
From these definitions we can already understand what the thermal amplitude is. This is the difference between the minimum temperature and the maximum temperature that is recorded in a place for a certain time. In other words, the thermal amplitude reveals how much the temperature varies at a site over a period.
In general, the thermal amplitude indicates how many degrees of difference there are between the coldest moment and the warmest moment of a day. Suppose that on April 14, 2011, in a city X, the lowest temperature recorded was 6º C (at 7.05 am), while the highest temperature reached 19º C (at 14.34 pm). The temperature range of this day, in that place, was 13 ° C.
It is also common for the thermal amplitude to be measured according to the average values for a long time. In the last decade, a country average minimum temperature is recorded 8 ° C and an average maximum temperature of 23 ° C. Thus it can be said that the temperature range of the nation is 15 ° C.
It should be noted that the thermal amplitude depends on several factors beyond the temperature, such as winds and humidity.
In the same way, it must be borne in mind that the existence of certain elements that are close to the place where the measurement is made also influences this thermal amplitude. We are referring specifically to the near existence of large bodies of water, such as the sea, since it interferes with caloric conductivity and what is also known as heat capacity.
The cloudiness, in the same way, influences the aforementioned amplitude because it hides the sun and also does the same, for example, as are the mountains and other systems framed within the topography.
In Spain it can be established that the places with a lower thermal amplitude are the Canary Islands, part of Galicia as well as areas of Asturias and Cantabria.