In our free time from work, we rush "to nature", to the forest, to the river - to breathe fresh air. All life on earth breathes: inhales oxygen, exhales carbon dioxide. Only green plants consume carbon dioxide from the atmosphere to synthesize vital carbon compounds. This process is known to be called photosynthesis.
Many measurements carried out in various climatic zones of the globe, over land and over the sea, show that everywhere in the atmosphere there is approximately the same amount of carbon dioxide. Its concentration is 0.03-0.04%.
What determines the concentration of carbon dioxide?
The content of carbon dioxide in the atmosphere depends on local conditions (it is clear that in large cities there is more of it), on the season and even on the time of day. These changes are not random, they have a certain regularity. Here is what, for example, studies have shown using infrared spectroscopy (a method that gives the necessary measurement accuracy). Observations were made on a field not far from a coniferous forest at a height of 2-2.5 meters above the ground, in a strip about half a kilometer long.
- The content of carbon dioxide changes most sharply during the day in spring and summer.
- Its maximum occurs at night: at this time, the concentration of carbon dioxide is 20% higher than the average level.
- Somewhat less pronounced daily highs, which fall at 11, 15 and 19 hours of the day.
The reason for such regular daily fluctuations, obviously, is the vital activity of plants: they breathe around the clock, and photosynthesis occurs only in the light and its intensity changes with the position of the Sun.
With regard to seasonal fluctuations, the concentration of carbon dioxide increases markedly in winter. In the second half of January - the first half of February, CO2 saturation in the air increases by 80-90%. Apparently, and this is to some extent connected with the vital activity of plants - in winter they consume less carbon dioxide. But it is also possible that the reason for such fluctuations is in the peculiarities of air mixing by turbulent flows in winter. In general, there is a relationship between the course of the temperature curve and the CO2 content in the atmosphere: lower temperatures correspond to higher CO2 content.