Abstract ID: 3.12438 | Accepted as Talk | Talk | TBA | TBA

Observations of atmospheric aerosols at high elevations play a crucial role in monitoring changes in atmospheric background composition, evaluating the effects of both anthropogenic and natural aerosols at a regional scale, and enhancing our understanding of aerosol-cloud interaction mechanisms. However, high-altitude observations are limited due to environmental and technical challenges.
We will present aerosol measurements collected at the Testa Grigia Observatory, at 3,480 m in the Italian Alps. This observatory was established in 1948 for cosmic ray measurements, and continuous monitoring of aerosol particle number size distribution (ranging from 0.25 to 35 micrometers) and aerosol absorption coefficients began in 2021.
Through multivariate statistical analysis of the variability in particle number size distribution over two-year period, we identified three distinct regimes: clean conditions, long-range dust transport episodes, and pollution transport events. Back trajectory analysis indicates that clean conditions occur when the observatory is influenced by air masses that spend most of their time in the free troposphere. Pollution transport events are characterized by an increase in particle numbers in the accumulation mode, occurring exclusively during the warm season when the boundary layer extends to higher elevations. During this regime, we observed higher particle loadings, particularly when local meteorology favors transport from the Po Valley. Dust transport episodes were noted during the spring and summer, coinciding with reanalysis provided by the CAMS (Copernicus Atmosphere Monitoring Service) models.
A better understanding of the link between aerosol microphysical properties and their sources and atmospheric transport is essential for modeling the impact of particulate matter on climate change and local weather patterns.