Update: 2019-11-26 16:35 Source: LUFTMY
Because poor air can have a significant impact on public health, it is important to understand how seasonal changes affect pollution levels. Generally speaking, the impact of winter and summer on air quality is different, but they will never be different from each other.
We often think that we will get more "fresh air" in warm weather, so we prefer outdoor activities.However, warm weather actually increases pollution levels.The increased solar radiation in summer will produce more photochemical oxidants, especially ozone.Ozone is a colorless active gas with strong oxidation. When it is in the stratosphere, it can block harmful radiation from the sun.However, when ozone is on the ground, in the troposphere, it becomes dangerous.
In summer, radiation from the sun is stronger, which causes ozone levels to rise on the ground.This can lead to dangerous air conditions in the lower atmosphere, where people move around.Ozone on the ground can cause dyspnea, cough and asthma.
In addition to these health problems, high ozone levels increase the incidence of other pollutants.Because ozone is a reactive gas, it can stay in stagnant summer air for a long time and mix with other pollutants in the air, including emissions from cars and power plants.The process is particularly bad in heavily trafficked areas, such as big cities, where nitrogen oxides are released into the atmosphere in greater quantities.
In addition, the increase in summer travel will significantly increase pollution levels. This explains why the peak season of tourist attractions is the place with the worst air quality.
On the better side, in summer, warm air is lower than cold air, which means that the resistance of toxic particles in the air to rise is smaller than in winter. Therefore, pollutants are more easily taken away from the atmosphere, bringing fresh air to people on the ground.
1.Serious damage caused by forest fires
In recent years, forest fires have been a problem that can not be ignored, especially in summer.
Recently, however, policy makers and scientific forecasters have become increasingly concerned about the relationship between forest fires and air quality - even if they occur miles from major cities.Last summer, forest fires severely affected the air quality of nearby cities.
2. More hurricanes and more smog?
Because of climate change, we see more hot and cold air mixing in the upper atmosphere, which leads to an increase in the number of extratropical cyclones, usually the powerful forces behind snowstorms and thunderstorms.
While large storms can be deadly, they are not always bad: when they hit large areas, they limit the formation of certain pollutants and drive haze out of cities.In 2019, however, tropical storms may no longer be beneficial.The new report shows that the air in the Arctic is warming twice as fast as the global average, which causes the air in the Arctic to warm faster than in the south.This is a problem because it means that temperate storms will occur more frequently, but the circulation of these storms will weaken, eliminating their air purification benefits.
In addition, the decrease of the circulation of extratropical cyclones may lead to climate warming, which will increase the level of ozone and generate more smog.
3 pollution caused by travel season
The increase of summer travel will greatly increase the emission level of automobile exhaust. Not only the traffic congestion on the road leads to the improvement of pollution level, but also the stagnation of travel vehicles is still the cause of this problem.