Why is it yellow in the morning?

There may be several reasons why the sky turns yellow in the morning:

1. Impact of sandstorm: Sandstorm blows up dust on the ground, making the air turbid, and the horizontal visibility is less than 1km. This weather phenomenon will cause the sky to appear yellow.

2. Effects of chemicals in the atmosphere: For example, chemicals such as sulfur dioxide, nitrogen oxides and carbon monoxide may make the sky yellow.

3. The influence of water vapor and dust in the air: When there is more water vapor and dust in the air, the yellow-orange light with longer wavelength scatters more, causing the sky to turn yellow.

4. Influence of temperature: When the temperature is low, the suspended particles in the air increase, which makes the sunlight scatter when it passes through the atmosphere, causing the sky to turn yellow.

These are the possible reasons why the sky turns yellow in the morning. The specific reasons need to be comprehensively judged according to the local weather, environmental conditions and the specific situation of the day.