Relative humidity and mixing height are both important factors that influence the dispersion of pollutants in the atmosphere.

Relative humidity is a measure of the amount of water vapor in the air relative to the maximum amount of water vapor that the air can hold at a given temperature. When relative humidity is high, the air is saturated with water vapor and cannot hold much more moisture. This can have an impact on the behavior of pollutants, as they may react with water vapor or become more soluble in the presence of high humidity.

Mixing height, on the other hand, refers to the height at which the atmosphere becomes well-mixed, allowing pollutants to disperse more evenly throughout the air. Mixing height is influenced by a variety of factors, including temperature, wind speed, and atmospheric stability. In general, when the atmosphere is unstable and there is a lot of turbulence, mixing height tends to be higher.

The relationship between relative humidity and mixing height is complex and depends on a variety of factors. In general, when relative humidity is high, the atmosphere may be more stable and less turbulent, which can reduce mixing height. This is because water vapor can act as a stabilizing agent in the atmosphere, making it more difficult for air masses to rise and mix with surrounding air. On the other hand, low relative humidity can lead to more turbulent conditions and higher mixing heights.

However, the relationship between relative humidity and mixing height can vary depending on local conditions, and other factors such as temperature and wind speed may have a greater influence on mixing height than relative humidity alone. Therefore, it is important to consider a range of factors when assessing the potential impact of relative humidity and mixing height on pollutant dispersion.