Source: wikibot/planetary-boundary-layer
= Planetary boundary layer
{wiki=Planetary_boundary_layer}
The planetary boundary layer (PBL) is a key part of the Earth's atmosphere that is directly influenced by the presence of the Earth's surface. It is the lowest portion of the atmosphere, typically extending from the surface up to about 1 to 2 kilometers (or approximately 0.6 to 1.2 miles) in altitude, although its thickness can vary depending on weather conditions, terrain, and time of day.