planetary boundary layer

The Planetary Boundary Layer (PBL) is the lowest part of the atmosphere, extending from the Earth's surface to about one or two kilometers up. It is where weather occurs and where human activities, like pollution and heat, significantly influence air quality and climate. The PBL changes throughout the day due to the heating from the sun, making it crucial for understanding wind patterns, temperature variations, and the dispersion of pollutants. Essentially, it acts as a bridge between the Earth's surface and the upper atmosphere, playing a key role in weather and climate systems.