#anlooh — Public Fediverse posts

The introduction of this 2024 preprint explains the basics regarding OHradicals, NOx, ozone, and methane.
#Mertens et al "The contribution of transport emissions to ozone mixing ratios and methane lifetime in 2015 and 2050 in the Shared Socioeconomic Pathways "
https://egusphere.copernicus.org/preprints/2024/egusphere-2024-324/
A term I don't really understand: Volative organic compounds, VOC
https://en.wikipedia.org/wiki/Volatile_organic_compound
Until I do I translate the term with "plant pheromones".

Tropospheric ozone is a people & plant killer and a #greenhousegas.
Ozone is needed to form OH radicals – which are needed to break down methane. When ozone is less abundant in the lower atmosphere=troposphere, OH radicals are also fewer, and CH4 lifetime is longer.

Interesting:
#Ozone concentration follows 2 formation pathways:
a) #NOx is hit by UV light
b) VOC are hit by UV.
When NOx concentration is low, ozone isn't automatically low in tandem. Because in our world today, if NOx is low = away from cities and fossil fuel combustion, the abundance of plant pheromones VOC is high and ozone just forms this way.

During COVID lockdowns:
"although NOx emissions were greatly reduced, measurements and results of model simulations showed only a slight decrease in O3 or, in some cases, regionally increasing O3 values."

Ah. Let's have a quick look at some old charts of CH4 measured in European stations in the ICOS network....

#anloCH4 #anloOH