Abstract
Atmospheric soot and organic particles from fossil fuel combustion and biomass burning modify Earth’s climate through their interactions with solar radiation and through modifications of cloud properties by acting as cloud condensation nuclei and ice nucleating particles. Recent advancements in understanding their individual properties and microscopic composition have led to heightened interest in their microphysical properties. This review article provides an overview of current advanced microscopic measurements and offers insights into future avenues for studying microphysical properties of these particles. To quantify soot morphology and ageing, fractal dimension (Df) is a commonly employed quantitative metric which allows to characterize morphologies of soot aggregates and their modifications in relation to ageing factors like internal mixing state, core-shell structures, phase, and composition heterogeneity. Models have been developed to incorporate Df and mixing diversity metrics of aged soot particles, enabling quantitative assessment of their optical absorption and radiative forcing effects. The microphysical properties of soot and organic particles are complex and they are influenced by particle sources, ageing process, and meteorological conditions. Furthermore, soluble organic particles exhibit diverse forms and can engage in liquid–liquid phase separation with sulfate and nitrate components. Primary carbonaceous particles such as tar balls and soot warrant further attention due to their strong light absorbing properties, presence of toxic organic constituents, and small size, which can impact human health. Future research needs include both atmospheric measurements and modeling approaches, focusing on changes in the mixing structures of soot and organic particle ensembles, their effects on climate dynamics and human health.
Original language | English |
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Article number | 65 |
Number of pages | 14 |
Journal | npj Climate and Atmospheric Science |
Volume | 7 |
Issue number | 1 |
DOIs | |
Publication status | Published - 8 Mar 2024 |
Bibliographical note
AcknowledgementsW.L. acknowledges funding from the National Key Research and Development Program of China (2023YFC3706301), the National Natural Science Foundation of China (42075096), and the Fundamental Research Funds for the Central Universities (K20220232). A.L. acknowledges support from the U.S. Department of Energy’s (DOE) Atmospheric System Research program, Office of Biological and Environmental Research (OBER), award DE-SC0021977. N.R. acknowledges support from the U.S. Department of Energy’s (DOE) Atmospheric System Research program, Office of Biological and Environmental Research (OBER), award DE-SC0022130.