Experiments on the ageing of sea spray aerosol are being performed at Aarhus University during June 2025 in the Piano@Aarhus campaign. We generate sea spray aerosols using the AEGOR sea spray simulation chamber and inject them into the AURA atmospheric simulation chamber, where they are aged by OH radicals and acidified by SO2. We also sample for bio-aerosols analysis using the plunging jet or diffuser for bubble generation. In this way both the fresh and the aged sea salt aerosol were characterized. The experiments are performed on the Mediterranean water samples at ~20°C, and the Arctic seawater samples at ~0°C.
CCN activity was probed using an online cloud condensation nuclei counter, and water uptake properties under subsaturated conditions were probed using an H-TDMA. The chemical composition of the sea spray aerosol was probed in all experiments using an Aerosol Mass Spectrometer. Chemical composition of the gas phase was probed using an SO2 monitor and a Proton-Transfer Reaction Mass Spectrometer. Bioaerosols were characterized using a mini bioaerosol sampler – during injection into the AURA chamber and after acidification. Ice nucelating particles were measured on a cold stage instrument.
