A laboratory simulation of plume dispersion in stratified atmospheres over complex terrain

Stratified flows over a three-dimensional topography have been investigated using a stratified towing tank to illustrate airflow pattern and plume behaviors under different conditions, aiming to investigate pollutant dispersion mechanism over Hong Kong Island. The stratified atmospheres are achieved by using stratified salt water. Various towing speeds are used to represent the different wind speeds. Some flow phenomena such as dividing streamline, leeward vortices and leeward wave are observed to explain the causes of high pollution over Hong Kong Island.