Is it fresh air in the morning, or fresh air at one or two o clock in the afternoon?

It should be in the afternoon, the sun has just come out in the morning, and the plants only carry out respiration in the evening, and do not carry out light and action, and the CO2 content is relatively high. After a morning of light and action, the oxygen content is high. It is generally believed that the air is good in the morning because of the high humidity caused by factors such as dew in the morning, but in fact the oxygen content is very low.

The key is to see what you define fresh. If you only count the oxygen content, around 2 points is the best. Because photosynthesis has been going on before.

At 2 o'clock, because it is the hottest time of the day, the leaves close the holes in order to avoid a large amount of water evaporation, and the photosynthesis is weak.

If you consider car exhaust, 8 or 9 o'clock and 4 or 5 o'clock in the afternoon should be the worst, and the traffic flow to and from work should be the worst. The old man said that the air was good in the morning, I explained earlier, they don't understand photosynthesis, in fact, the oxygen content was very low at that time, but the sun had just come out, the air temperature was low, and the humidity was high, which made people feel the most comfortable.

In the morning, there is less oxygen and less inhalable particulate matter, and in the afternoon there is more oxygen and more inhalable particulate matter. In the afternoon, the emission pollution was aggravated, and the photochemical reaction was strong. All things considered, good morning in the city and good afternoon in the countryside.

In the afternoon, because the tree had just woken up from sleep in the morning, it did not release as much oxygen.

The freshest air in the day should be around 10 o'clock in the morning, if you choose according to your answer, it is the afternoon, in fact, it is almost the same, not to mention the specifics! I can't say a word or two!

Dear, glad to answer for you. In general, the air in the early morning is relatively clean, especially if there are no large sources of pollution such as traffic, industry, etc. This is because, at night and early in the morning, the sun's radiation is weak or absent, and the pollutants in the atmosphere are relatively stable, and there is no chance of decomposition and oxidation by solar radiation, so the air is relatively fresh.

At the same time, due to the vigorous photosynthesis of plants at this time, they can absorb a large amount of carbon dioxide and release oxygen, which is also conducive to the freshness of the air. However, not all areas and periods of time are clean in the morning, for example, in urban centers, traffic concentration areas, industrial parks, etc., even in the early morning air may have high concentrations of pollutants. Therefore, the specific situation of Yuqin needs to be analyzed according to the actual situation of Qingzhibi.

According to current research, the air in the morning is the worst except for the night.

In fact, if you think about it for yourself, you can understand that in the morning green plants do not photosynthesize, and of course the carbon dioxide content is very high. But "morning exercise" morning exercise is not unreasonable, because the soot content in the morning air is relatively low during the day; In addition, there are relatively few vehicles in the morning, so safety is more guaranteed.

That's why the air is bad in the morning. If you want to come out in the morning, then wait for the sun to come out first!

Actually, 10 a.m. to 2 p.m. is the best.

In the morning, as the sun rises, the garden plants in the green space begin to photosynthesize, absorb carbon dioxide and release oxygen, so the carbon dioxide content in the ambient air gradually decreases, and the carbon dioxide content drops to the lowest point around noon; At night, plant photosynthesis stops and respiration begins, and carbon dioxide is released into the air due to the activities of city people and vehicles, and the carbon dioxide in the air begins to rise. So in terms of the freshness of the ambient air, it is best between 10 a.m. and 2 p.m., and early morning is not the best time.

Between 9 and 10 a.m., the air quality is at its best. Because, in the previous period, because the dew or frost settles the floating matter in the air, there will be a lot of pollutants in the air on the surface of the ground, and in the following period, because some exhaust fumes or dust will pollute the air, so the air quality between 9 and 10 o'clock in the morning should be the best in comparison.

Also, here's a tip for you: if you exercise in the morning, you shouldn't exercise on foggy days.

The air is at its freshest around 10 a.m. and 3-4 p.m. 24 hours a day; Air pollution is more severe in the morning, evening and evening, with the peak pollution at around 7 p.m. and 7 a.m., when the air is at its worst.

The reason for the difference in the freshness of the air throughout the day is mainly due to meteorological factors. Due to the obvious change of vertical temperature difference between day and night, when the ground temperature is higher than the upper-air temperature, the air on the ground is easy to rise, and pollutants are easy to be carried to the upper altitude and disperse. When the ground temperature is lower than the upper-air temperature, an "inversion layer" is formed in the sky, which presses against the ground like a large cover, so that various pollutants in the ground air cannot diffuse. Inversion is generally seen at night, in the morning and in the evening, so the air is at its most polluted during these times.

During the day, when the sun comes out, the ground temperature rises rapidly, and the inversion layer gradually dissipates, so the pollutants spread quickly. Generally after 10 a.m., the ground air is fresh.

Most people will feel that in the morning, because plants do not absorb CO2 at night, and carbon dioxide affects your breathing, you will feel that the air is cleaner than last night! In fact, the air is the best in the afternoon! Thank you.