Urban landscapes interact via complex physical processes with the atmosphere resulting in a so-called urban climate1. A well-known illustration is the urban heat island effect which describes the increased temperatures in urban landscapes with respect to the rural surroundings. This phenomenon leads to additional heat stress in cities2 and impacts power consumption3, air pollution4, ecology5, etc. Cities are densely populated economic hubs and therefore very vulnerable to weather extremes. Projected urbanization and climate change indicate the risks in urban areas will increase6. Improved urban climate understanding is therefore crucial to permit decision makers to make our cities resilient.

High-accuracy meteorological observations in cities are essential for urban climate science7. Given the substantial investments needed for the installation and maintenance, only a limited number of long-term monitoring networks is operational over the world. These networks often measure different variables, use different data formats and are maintained by different institutes, which explains why today’s urban climate research is typically limited to case studies in single cities8-11. Urban climate science would strongly benefit from collaboration among the different research institutes operating urban climate networks. First, such a network of networks would permit to share experiences on technology (e.g. sensors, communication, energy), the selection of measurement locations, the interaction with local stakeholders (e.g. policy maker), etc. This would allow to learn from the successes and failures of others thereby improving the quality and durability of existing and future urban monitoring networks. Secondly, by gathering the operational observation networks in European cities this proposal facilitates going beyond single city studies towards more systematic urban climate studies. The collaboration creates the possibility to investigate the urban climate impact, to validate highresolution urban models and to study the interaction between urbanization and climate change, in different cities of varying sizes over all European climatic zones. Thirdly, the network creates a forum for European urban climate groups facilitating future joint research, projects and publications.

Via the organization of (virtual) meetings, a symposium and scientific visits the scientific research network will initiate European collaboration, motivate the exchange of data, work out standardized observational practices and stimulate joint research. Ultimately the initiative intends to strengthen the urban climate research by gathering the main European research groups active in urban climate monitoring. The projected outcome over 5 years consists of joint publications, research initiatives and project proposals at a European level.

Given its strong recent rise in the establishment of urban observations, modelling and impact studies, Flanders is in an excellent position to address the urgent need to initiate such a European network. The proposal gathers 10 research institutes collecting urban meteorological data including the most prominent European urban climate networks and scientists. From the Flemish side, researchers from UGent, KULeuven, RMI and VITO active on urban climate networks, modelling or impact studies are included. Backed by their expertise of installing the MOCCA network, the first long term meteorological network in a Belgian city, and the recently approved VLINDER citizen science project, which will monitor the microclimate at 50 locations in Flanders and Brussels, Atmospheric Physics group (UGent) will coordinate the scientific research network.  

References: (1) Oke, T. (1982) QJRMS. 108, 1-24. (2) Conti, S. et al. (2005) Env. Res. 98, 390-399. (3) Santamouris, M. (2014) Energ. Build. 82, 100-113. (4) Sarrat, C. et al. (2006) Atm. Env. 40, 1743-1758. (5) Merckx T., et al. (2018) Nature. 558, 113-116. (6) Bader, D.A. et al. (2018) ARC3.2 report. (7) Muller, C. (2013) IJOC. 33, 1585-1600. (8) Heaviside, C. et al. (2016) Env. Health. 15, 49-59. (9) Steeneveld, G.J. et al. (2011) JGRA. 116, 1-14. (10) Suomi, J. et al. (2012) 32, 451-463. (11) Chow, W. et al. (2006) 26, 2243-2260