Her research focuses on urban meteorology and climate and their interaction with local air quality. She leads an urban meteorology research group which uses novel atmospheric observations and modelling to study the interaction between urban surface and the atmosphere such as greenhouse gas emissions to the atmosphere and how they are modified by land use changes and human activities and how urban structures modify wind flow and turbulence in urban areas. Leena Järvi is PI of the ICOS (Integrated Carbon and Observation System infrastructure) associated ecosystem station in Helsinki and board member of the International Association for Urban Climate.