The aim of this study is to investigate the problems caused by discharge of polluted air from tunnels into the environment with a specific focus on residential areas. In city tunnels, portal or stacks, pollutant management is a big challenge. Nowadays, air quality management, particularly in urban tunnels, is considered as a part of the ventilation system design. The goal is to see the environm...

Specific objectives include: 1) test the nonlocal mixing parameterization using a Large-Eddy Simulation (LES) model and incorporate it into a mesoscale model, 2) further develop the Lagrangian random particle dispersion model and test its turbulence parameterization, and 3) further develop a system for evaluating atmospheric models using tracer measurements. This work is supported by the Office...

The diurnal cycle of the North American monsoon is analyzed based on the output from a mesoscale model simulation. Statistically significant diurnal cycle in precipitation is identified, with heavy precipitation—essentially convective—dominating in local afternoons. Temporal evolution of key parameters in relation to precipitation is investigated, based on which a sequence of the dynamic/thermo...