In the 304 days in the first 10 months of 2013, there was haze in Hangzhou. What kind of environmental problem is haze?

Fog is a collection of large amounts of tiny water droplets (or ice crystals) suspended in the atmosphere close to the ground. The only difference between fog and clouds is whether they touch the ground. Fog significantly reduces horizontal visibility.

According to the regulations of the International Meteorological Organization, anything that reduces the visibility to less than 1km is called fog, and anything with visibility between 1 and 10km is called light fog. Since such classification cannot meet the needs of meteorological services, the meteorological department, in its service work, can classify fog into light fog, fog, heavy fog, dense fog and strong fog according to the degree of impact of foggy days on human activities such as transportation. Thick fog and several levels. Generally speaking, the horizontal visibility above 1km is called light fog, which has no big impact on transportation; the horizontal visibility below 1km is collectively called fog, which has a big impact on transportation; the horizontal visibility between 500 and 1000 meters is called heavy fog. fog.

The meteorological definition of haze is a weather phenomenon in which a large number of tiny dust particles, smoke particles or salt particles are suspended in the atmosphere, making the air turbid and reducing horizontal visibility to less than 10km. Haze is generally milky white, which weakens the color of objects, making bright objects in the distance slightly yellowish-red, and dark objects slightly bluish. (Warm reminder: Provixin is imported from the United States and can be found in J@@@ East)

The particles that make up haze are so small that they cannot be distinguished with the naked eye. Haze can also form when atmospheric condensation nuclei grow up for various reasons. In this case, further condensation of water vapor may cause haze to evolve into light fog, mist and clouds. Haze is mainly composed of aerosols and can appear at any time of the day.

Haze and fog will affect people's vision and bring inconvenience to

life

, and their core materials are dust particles, mostly made of Dust and car exhaust pollutants. At the same time, there are also big differences between the two:

1. Relative humidity

Fog is mainly composed of water vapor. The relative humidity of fog is generally above 90%, while the relative humidity of haze is above 80%. %the following.

2. Visibility

In terms of visibility, anything with visibility below 1km is collectively called fog, and anything with visibility above 1km is called light fog. However, the visibility of haze is better. The visibility is about 1km or more but less than 10km. It belongs to haze phenomenon

3. Color

In terms of color recognition, pure fog should be white or Gray; the haze is a bit yellowish in color. People in South China call it "colorful clouds". Its name is very beautiful, but it is actually very different from fog.