[DocSavage87]

In an outdoor setting, settling, dilution, dispersion are probably the dominant modes of decontamination.  The droplets fall to the ground, and the aerosols are carried by the wind and mixed with fresh air to the point where the concentration of viral particles per unit of volume drops by several log orders.

BC

Whatever is left is taken care of by natural sunlight.  Here's a paper on inactivation by sunlight:
https://academic.oup.com/jid/article/222/2/214/5841129

I think this is from the biowarfare team in MD that suggested very rapid inactivation in direct sunlight, like below a minute originally, but these results suggest longer exposure is necessary.

[DocSavage87]

In an outdoor setting, settling, dilution, dispersion are probably the dominant modes of decontamination.  The droplets fall to the ground, and the aerosols are carried by the wind and mixed with fresh air to the point where the concentration of viral particles per unit of volume drops by several log orders.

BC

Whatever is left is taken care of by natural sunlight.  Here's a paper on inactivation by sunlight:
https://academic.oup.com/jid/article/222/2/214/5841129

I think this is from the biowarfare team in MD that suggested very rapid inactivation in direct sunlight, like below a minute originally, but these results suggest longer exposure is necessary.