In the first part of this seminar I will discuss how trees affect urban air quality using our large-eddy simulation code uDALES which for which a tree model was developed recently that models drag, evaporation, shading and deposition. I will discuss differences in air quality with and without trees and discuss the effect of atmospheric stability. A conceptual model is formulated which demonstrates whether trees can be expected to improve or deteriorate air quality. In the second part I will discuss methods that provide insight on where one should reduce emissions in order to achieve the highest possible exposure reduction. This is a complicated question as streets are typically arranged in complex networks through which pollution is exchanged.
