Atmospheric particulate matter influences global climate through direct interactions with incoming solar radiation and through impacts on the production and radiative properties of clouds. Both natural aerosols emitted from the oceans and arid regions, and biogenic gases that lead to the formation of secondary particulate matter significantly contribute to the global burden of particulate matter in the atmosphere. Therefore, understanding the composition, quantity, and climate forcing properties of aerosols from these sources is crucial for quantifying the radiative impact of aerosols on a global scale. To address this issue, my research is aimed at understanding how atmosphere-biosphere and air-sea interactions impact the physicochemical properties of aerosols and their water-uptake properties. In this seminar, I will present results from measurements using state-of-the-art analytical techniques. Key findings include: (i) the potential for particle acidity to enhance the formation of biogenic secondary organic aerosol, and (ii) insight into the mineralogy and cloud nucleating potential of unprocessed, mineral dust emitted from dried lakebeds. These findings have implications for constraining the budgets of particles that can facilitate the formation of cloud droplets in the atmosphere.