AN OVERVIEW Of THE URBAN BOUNDARY LAYER ATMOSPHERE NETWORK IN HELSINKI

A lthough urban areas comprise a very small fraction of Earth’s land cover (Schneider et al. 2009), over half of global population live in urban agglomerations. Therefore, it is important to monitor, understand, and predict the modifications occurring in local weather and climate due to urbanization, particularly for the perspective of accurate high-resolution weather and air-quality forecasting and climate-sensitive urban design and planning. Cities are characterized by a high fraction of impervious surfaces, which modify both surface energy and water balances, further affecting atmospheric boundary layer (ABL) turbulence and weather processes. Cities are also the main “area sources” of air pollutants with detrimental effects on human health and comfort. Cities can generate, modify, and/or amplify many processes behind global changes such as  A dedicated intensive research-grade observational network in Helsinki enables studies of the physical processes in the urban atmosphere at high latitude.