Urban canopy layer

From Glossary of Meteorology

urban canopy layer

The layer of air in the urban canopy beneath the mean height of the buildings and trees.

Its climate is dominated by microscale processes due to the complex array of surfaces (their orientation, albedo, emissivity, thermal properties, wetness, etc.). It is a zone of multiple reflection and emission, wakes and vortices, especially in the urban canyons.
Compare urban boundary layer.