Short answers, pulled from the story.
Frederick G. Donnan likely coined the term aerosol during World War I to describe aero-solutions and clouds of microscopic particles in air. The word was created by drawing an analogy to the term hydrosol which describes a colloid system with water as the dispersed medium.
The eruption injected massive amounts of sulfur dioxide into the stratosphere which rapidly converted into droplets of sulfuric acid that formed a global aerosol layer. This volcanic aerosol persisted for up to two years and lowered global temperatures by approximately 0.5 degrees Celsius while reflecting sunlight back into space.
Regulations on fuel significantly cut sulfur dioxide emissions from international shipping by approximately 80% in 2020. This sudden reduction removed the cooling effect that had been masking the true extent of global warming and resulted in unexpectedly large global warming in 2023 and 2024.
The United States Environmental Protection Agency replaced the older standards for particulate matter based on Total Suspended Particulate with another standard based on PM10 in 1987. The agency then introduced standards for PM2.5 in 1997 to reflect the growing understanding of the health risks associated with different sizes of aerosol particles.
Scientists use a log-normal distribution because the normal distribution usually does not suitably describe particle size distributions due to the skewness associated with a long tail of larger particles. The log-normal distribution has no negative values and can cover a wide range of values to fit many observed size distributions reasonably well.
Aerosols interfere with formations that interact directly with radiation by modifying the size of cloud particles in the lower atmosphere. This process changes the way clouds reflect and absorb light thereby modifying the Earth's energy budget and influencing climate patterns.