Climatological assessment of the vertically resolved optical aerosol properties by lidar measurements and their influence on radiative budget over the last two decades at UPC Barcelona

In the last two decades, several scientific studies have highlighted the adverse effects, primarily on population health, transportation, and climate, of urban atmospheric particulate due to anthropogenic emissions. For these reasons, aerosols have been monitored through both, remote sensing and in-situ observation platforms, also to establish if the reduction emission policies implemented at the government level have had positive outcomes. In this study, for the first time, we assess how the vertically resolved properties of the atmospheric particulate have changed and consequently their radiative effect during the last twenty years in Barcelona, Spain, one of the largest metropolitan areas of the Mediterranean basin. This study is carried out in the frame of the ACTRIS project through synergy between lidar measurements and the meteorological variables, e.g. wind, temperature, and humidity at the surface. This research, thanks to twenty-year measurements, can shed some light on the meteorological processes and conditions that can lead to haze formation and can help decision-makers to adopt mitigation strategies to preserve large marine Mediterranean metropolitan regions.