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1. Imaging aerosols with digital holography

   M. J. Berg, Y. W. (March 2018, Physics today)

   The shape and size of aerosol particles influence whether they heat or cool Earth and its atmosphere. 

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2. Modelling effects of alkylamines on sea salt aerosols using the Extended Aerosols and Inorganics Model

   https://doi.org/10.59720/20-234  

   Chang, Eugene; Yalamanchili, Tej; Qiu, Chong (January 2022, Journal of emerging investigators)

   Sea salt aerosols are known to serve as effective cloud condensation nuclei and are prominent contributors of light scattering in the atmosphere. More light scattering reduces solar radiations to the Earth and lowers the global temperature. Researchers observed that ambient sea salt aerosols may contain ammonium sulfate (AS) and sodium chloride (NaCl). Recent studies showed that alkylamines, derivatives of ammonia, can react with ammonium salts in the aerosol, displacing ammonium and altering the particle’s properties. Our study investigated the effects of atmospheric alkylamines on the properties of sea salt aerosols using a chemical system of methylamine (MA), AS, and NaCl. We determined the relative humidity when these aerosols start to absorb water vapor from the air (deliquescent relative humidity, DRH), and concentrations of ammonia and MA in aqueous/gas phases using the Extended Aerosols and Inorganics Model. Our findings indicate a notable negative relationship between MA concentration and the DRH for both AS and NaCl. We determined that five parts per billion or higher of MA effectively lowered the DRH of sea salt aerosol particles. The concentrations of ammonia and MA in aqueous and gas phases had a complex dependence on MA concentration and aerosol chemical composition. Aerosol deliquescence often leads to cloud/fog processing which may cool the Earth by reflecting sunlight away from the surface. Therefore, our results implicate a potential role for alkylamines in climate change, suggesting the importance of monitoring alkylamine concentrations in the atmosphere. Future studies are needed to better predict the deliquescent behaviors of aerosols, namely particles containing AS and NaCl, such as those found near coasts. 

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3. An Optofluidic Nanoplasmonic Sensor for Aerosols

   https://doi.org/10.1109/IPC57732.2023.10360531  

   Jiang, Hao; Judge, Sophia (November 2023, IEEE)
4. How Volcanic Aerosols Globally Inhibit Precipitation

   https://doi.org/10.1029/2023GL107930  

   McGraw, Zachary; Polvani, Lorenzo_M (June 2024, Geophysical Research Letters)

   Abstract Volcanic aerosols reduce global mean precipitation in the years after major eruptions, yet the mechanisms that produce this response have not been rigorously identified. Volcanic aerosols alter the atmosphere's energy balance, with precipitation changes being one pathway by which the atmosphere acts to return toward equilibrium. By examining the atmosphere's energy budget in climate model simulations using radiative kernels, we explain the global precipitation reduction as largely a consequence of Earth's surface cooling in response to volcanic aerosols reflecting incoming sunlight. These aerosols also directly add energy to the atmosphere by absorbing outgoing longwave radiation, which is a major cause of precipitation decline in the first post‐eruption year. We additionally identify factors limiting the post‐eruption precipitation decline, and provide evidence that our results are robust across climate models. 

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5. Bubbles spray aerosols: Certitudes and mysteries

   https://doi.org/10.1093/pnasnexus/pgac261  

   Villermaux, Emmanuel; Wang, Xiaofei; Deike, Luc; Yortsos, ed., Yannis (November 2022, PNAS Nexus)

   Abstract Ocean spray aerosol formed by bubble bursting are at the core of a broad range of atmospheric processes: they are efficient cloud condensation nuclei and carry a variety of chemical, biological, and biomass material from the surface of the ocean to the atmosphere. The origin and composition of these aerosols is sensibly controlled by the detailed fluid mechanics of bubble bursting. This perspective summarizes our present-day knowledge on how bursting bubbles at the surface of a liquid pool contribute to its fragmentation, namely to the formation of droplets stripped from the pool, and associated mechanisms. In particular, we describe bounds and yields for each distinct mechanism, and the way they are sensitive to the bubble production and environmental conditions. We also underline the consequences of each mechanism on some of the many air-sea interactions phenomena identified to date. Attention is specifically payed at delimiting the known from the unknown and the certitudes from the speculations. 

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