humidity and virus transmission

 

Low ambient humidity impairs barrier function and innate resistance against influenza infection

https://www.pnas.org/content/116/22/10905

2m dew point, ERA5

In Kelvin

Temperature to which the air, at 2 metres above the surface of the Earth, would have to be cooled for saturation to occur.It is a measure of the humidity of the air. Combined with temperature and pressure, it can be used to calculate the relative humidity. 2m dew point temperature is calculated by interpolating between the lowest model level and the Earth's surface, taking account of the atmospheric conditions. Temperature measured in kelvin can be converted to degrees Celsius (°C) by subtracting 273.15.

https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-land?tab=overview


Low dew point == low humidity according to wikipedia, because less vapor is need for condensation
https://en.wikipedia.org/wiki/Dew_point

Dew point		Relative humidity at 32 °C (90 °F)
Over 26 °C	Over 80 °F	73% and higher
24–26 °C	75–80 °F	62–72%
21–24 °C	70–74 °F	52–61%
18–21 °C	65–69 °F	44–51%
16–18 °C	60–64 °F	37–43%
13–16 °C	55–59 °F	31–36%
10–12 °C	50–54 °F	26–30%
Under 10 °C	Under 50 °F	25% and lower

This seems to explain that the condensation on leaves is often seen in the early morning, but not during the daytime. So, if a mutant strain has a lower dew point, it tend be in drier locations. If a strain has a higher dew point, it tends to be more humid locations