Fig. 6.

Visualizations demonstrating the effect of particle size (and mass) on the modelled spreading of the cough-released aerosol cloud. For better sense of scale, bystanders are placed 8 m from the coughing person. Instantaneous views on the state of the cloud are shown for realizations where the particles have (a) no mass, (b) $1000\mathrm{kg}{\mathrm{m}}^{-3}$ density and $10\mathrm{\mu }\mathrm{m}$ diameter and (c) $1000\mathrm{kg}{\mathrm{m}}^{-3}$ density and $20\mathrm{\mu }\mathrm{m}$ diameter. Images on the left column are at $t=20\mathrm{s}$ and on the right column at $t=120\mathrm{s}$. Below, (d) presents the time evolution of the mean elevation of the 99th percentile concentration highlighting the different descent rates. Droplets in these size scales have ${\tau }_{\mathit{evap}}<1\mathrm{s}$ and they would become aerosol-like droplet nuclei very rapidly.