Smoke is a suspension of airborne particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires, but may also be used for pest control (fumigation), communication, defensive and offensive capabilities in the military, cooking, or smoking. It is used in rituals where incense, sage, or resin is burned to produce a smell for spiritual or magical purposes. It can also be a flavoring agent and preservative.
An aerosol is a suspension of fine solid particles or liquid droplets in air or another gas. Aerosols can be natural or anthropogenic. Examples of natural aerosols are fog or mist, dust, forest exudates, and geyser steam. Examples of anthropogenic aerosols include particulate air pollutants, mist from the discharge at hydroelectric dams, irrigation mist, perfume from atomizers, smoke, dust, steam from a kettle, sprayed pesticides, and medical treatments for respiratory illnesses. When a person inhales the contents of a vape pen or e-cigarette, they are inhaling an anthropogenic aerosol.
Soot is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolysed fuel particles such as coal, cenospheres, charred wood, and petroleum coke that may become airborne during pyrolysis and that are more properly identified as cokes or char.
Cloud condensation nuclei (CCNs), also known as cloud seeds, are small particles typically 0.2 µm, or one hundredth the size of a cloud droplet. CCNs are a unique subset of aerosols in the atmosphere on which water vapour condenses. This can affect the radiative properties of clouds and the overall atmosphere. Water requires a non-gaseous surface to make the transition from a vapour to a liquid; this process is called condensation.
Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The term aerosol commonly refers to the particulate/air mixture, as opposed to the particulate matter alone. Sources of particulate matter can be natural or anthropogenic. They have impacts on climate and precipitation that adversely affect human health, in ways additional to direct inhalation.
An ice nucleus, also known as an ice nucleating particle (INP), is a particle which acts as the nucleus for the formation of an ice crystal in the atmosphere.
Veronica Vaida is a Romanian-American Chemist and Professor at the University of Colorado Boulder. She is an expert in environmental chemistry and aerosols.
Heather Cecile Allen is a research chemist, who leads the Allen Group at Ohio State University. Allen's research focuses on interfacial phenomena, particularly those involving water and air. Her work has broad application ranging from medicine to climate change. She also develops nonlinear optical spectroscopy and microscopy instruments for the examination of interfacial surfaces.
Barbara J. Finlayson-Pitts is a Canadian-American atmospheric chemist. She is a professor in the chemistry department at the University of California, Irvine and is the Director of AirUCI Institute. Finlayson-Pitts and James N. Pitts, Jr. are the authors of Chemistry of the Upper and Lower Atmosphere: Theory, Experiments, and Applications (1999). She has been a member of the National Academy of Sciences since 2006 and is the laureate for the 2017 Garvan–Olin Medal. In 2016 she co-chaired the National Academy of Science report "The Future of Atmospheric Chemistry Research"
Vicki H. Grassian is a Distinguished Professor in the Department of Chemistry and Biochemistry at the University of California, San Diego. She also holds the Distinguished Chair in Physical Chemistry.
Kimberly A. Prather is an American atmospheric chemist. She is a Distinguished Chair in Atmospheric Chemistry and a Distinguished Professor at the Scripps Institution of Oceanography and Department of Chemistry and Biochemistry at UC San Diego. Her work focuses on how humans are influencing the atmosphere and climate. In 2019, she was elected a member of the National Academy of Engineering for technologies that transformed understanding of aerosols and their impacts on air quality, climate, and human health. In 2020, she was elected as a member of the National Academy of Sciences. She is also an elected Fellow of the American Geophysical Union, the American Association for the Advancement of Science, American Philosophical Society, and the American Academy of Arts and Sciences.
Barbara Ann Maher is a Professor Emerita of Environmental Science at Lancaster University. She served as director of the Centre for Environmental magnetism & Palaeomagnetism until 2021 and works on magnetic nanoparticles and pollution.
Sonia Maria Kreidenweis is an American Professor of Atmospheric Sciences at Colorado State University. Her research considers aerosols and their impact on weather and the climate. She has previously served as President of the American Association for Aerosol Research and was a board member of the American Meteorological Society. She was elected a Fellow of the American Geophysical Union in 2019.
Lynn Russell is a professor of atmospheric chemistry at the Scripps Institute of Oceanography a division of the University of California, San Diego in La Jolla, California.
Julia Yvonne Schmale is a German environmental scientist. She is a specialist in the micro-physical makeup of the atmosphere, in particular aerosols and their interaction with clouds. She is a professor at EPFL and the head of the Extreme Environments Research Laboratory (EERL). She is a parcipant in the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expeditions.
Dusan Licina is an engineer and researcher specializing in indoor air quality, building ventilation, and human exposure. He is a professor at EPFL and head of the Human-Oriented Built Environment Laboratory.
José Luis Jiménez-Palacios is a Spanish–American chemist and engineer. As a professor of Chemistry at the University of Colorado Boulder, Jimenez contributed to the establishment of the Aerodyne Aerosol Mass Spectrometer, an instrument for real-time analysis of aerosol size and composition.
Kerri Pratt is an American chemist who is Associate Professor of Chemistry at the University of Michigan. Her research considers atmospheric chemistry and how it impacts human health. She studies the interactions of atmospheric gases using mass spectrometry based techniques.
Vivian Faye McNeill is an American atmospheric chemist who is Professor of Chemical Engineering at Columbia University. She leads the University's initiative Clean Air Toolbox for Cities. McNeill provided expert guidance on aerosols and ventilation throughout the COVID-19 pandemic.
Staci Simonich is an American environmental scientist who is a professor and dean for the College of Agricultural Sciences at Oregon State University. Her research considers how chemicals move through the environment. She was appointed Fellow of the American Association for the Advancement of Science in 2021.
