Urban canyons
From Glossary of Meteorology
urban canyons
The characteristic geometry formed by a city street and its flanking buildings.
Together with the intervening roofs they provide a first-order repetitive structure to cities with characteristic patterns of sunlight and shade and cross-street vortices. Commonly described by their nondimensional aspect ratio H/W, where H is the mean height of the buildings and W the width of the street.
