Urban Trasport based Emissions: Multi-scale modelling approach using WRF and MUNICH models in Dublin, Ireland

Multi-scale atmospheric modelling allows the integration of drivers and processes that dominate at different spatial and temporal scales. In cities, this approach is needed to capture the effects of micro-scale (building and street) impacts on local (neighborhood) and urban scale atmosphere and vice-versa. This integration is needed to understand and manage urban emissions, which are highly heterogenous over time and space. This work focusses on Carbon emissions which are the subject of urban-scale policies to create low (and even zero) Carbon cities. The research presented here couples the Weather Research Forecasting (WRF) and Model of Urban Network of Intersecting Canyons and Highways (MUNICH) models to simulate Carbon emissions in Dublin (Ireland) with a view to developing neighborhood-scale mitigation policies. Initially, WRF-chem is applied to nested domains to capture regional, national, and urban effects: the island of Ireland is simulated at a 1 km resolution and Dublin city at 250 m resolution. The model setup includes a comprehensive treatment of meteorology, land use (including urban cover using WUDAPT derived Local Climate Zones (LCZs)) and biogenic/anthropogenic emissions and sequestration. Following evaluation, the WRF simulations are used to simulate the mixing of transport-based Carbon emissions using MUNICH, which requires details on the characteristics of the street network (e.g., width and height). The Carbon emissions will be estimated based on modelled traffic flows. The results of the simulations will be compared with street-level measurements of Carbon concentrations. The objective of this work is to create a modelling infrastructure suited to the development of urban policies to mitigate Carbon emissions.