When we talk about meteorology there are different types of phenomena that can occur annually and that have a unique origin and characteristics. Today we are going to talk about the Canicula. This name raises the dogs and being there seems to have come out the extraction of “a dog's day ago”. Although dogs have little to do with the meaning of heatwave. The dog days are a period when it is very hot and refers to Silvio's star in the constellation Canis Maior, which during these days becomes much brighter in the sky.
In this article we are going to explain what canicula is, what its characteristics and origin are.
When the summer period arrives, the constellation reaches a maximum level of billions in the sky. The appearance of Sirius made the ancestors tremble as it meant that it was going to be very hot. It was known as the scorcher. This constellation, being brighter, was thought to emit more heat in conjunction with the sun. Both generated a contribution of heat that made those days the hottest of the whole year. Today the hottest days do not coincide with the heliacal rise of Sirius, which is observed in early September. However, the canicula has so penetrated the tradition that it continues to be used.
Canicula period in Spain
Canicula is nothing more than the statistically hottest period of the year. In Spain we have the hottest days of the year between July 15 and August 15. Its start does not coincide with the beginning of summer is the only thing, but rather is in the middle. The fact that this occurs in this way is mainly due to three factors. We are going to analyze which are the main factors that make the summer heat not correspond to the astronomical summer:
- In these dates the sun shines in the northern hemisphere more perpendicular than ever. This causes the inclination of the solar rays to be direct. The inclination of the sun's rays is much lower in winter, so it transmits much more radiation. After a few weeks with this scenario, the ground overheats and distills heat. Let's not forget that if we add to this the heat island effect of cities, they can become unbearable heat.
- The sea has higher temperatures and its thermoregulatory action begins to languish. We know that the sea takes longer to acclimatize to reach the temperatures of the atmosphere. The air becomes colder or warmer faster than the sea. Therefore, it must be taken into account that in order for the sun's rays to heat the entire mass of the ocean, sufficient time must pass for it.
- A few weeks earlier, having lower records on its surface, it refreshes the atmosphere through the sea breezes and at that moment not so much anymore.
Heat waves and canicula
Keep in mind that canicula is not the same as heat wave. While the former is a statistically warmer period and falls on more or less the same dates every year, heat waves have a more capricious and random distribution. It is true that on many occasions they coincide in time. It is normal that added to a statistically hotter period it can be related to heat waves. This heat increases the average temperatures and statistically becomes warmer. For example, Between July 23 and 25, 1995, a heat wave left records of 46 degrees in the Seville and Córdoba observatories.. These values are extraordinary but they are not very distant from the two 43-44 degrees that are normally present on these dates. These temperatures are usually seen in the Guadalquivir depression.
Being in the middle of summer it is normal for the thermometers to rise and increase even more in cities. Canicula is also known for being a period of mid-summer intra-festival drought. It usually lasts a maximum of about 40 days and is where there is the highest suffocating temperature.
Among the characteristics that we have of the canicula we see the following:
- Temperatures above 37 degrees: These temperatures can frequently generate some health problems for the most vulnerable people. Although heat waves are more dangerous to be faster, heat waves can be more persistent.
- Decrease in rainfall: high temperatures prevent the generation of rain clouds due to the rise of hot air and a decrease in the environmental thermal gradient.
- Excessive air heating: the air becomes so hot that it circulates from one place to another more quickly.
- Totally clear sky: is related to the aforementioned. High temperatures slow the formation of rain clouds.
In the canicula it is common to find several cities in Spain in which thermometers touch or even exceed 40 degrees. Some forecasts are usually 45 degrees, especially if you add the effect of a heat wave in full heat. These high temperatures are accompanied by fires and droughts. Droughts are serious periods that affect vegetation and water resources by humans.
Of course, it should be mentioned that climate change is worsening the canicula situation every year. That is, there is a higher average temperature during these 40 days than the canicula usually lasts.
Some of the tips that are given to combat these days of intense heat, are the following:
- Avoid the direct exposure to the sun, especially at noon, which is when the sun's rays have a lower degree of inclination and the temperatures are higher.
- Drinking water continuously to avoid dehydration.
- Eat fresh food
- Apply sun cream to avoid burns
- Use umbrellas, Light clothing and a hat to protect yourself from the sun.
I hope that with this information you can learn more about the canicula and its characteristics.