4 ms·

I don't know if they even have that data for that length of time. You might find some info in literature regarding the difference in UV exposure in areas under

by rrmm 6y ago

I don't know if they even have that data for that length of time. You might find some info in literature regarding the difference in UV exposure in areas under the ozone hole vs areas of more normal exposure. As an aside, don't get misled by nutters talking about ground level UVC levels. They don't know what they're talking about and are citing people who don't know how to use their UV-C meters (which are sensitive at wavelengths other than UVC and therefore require extensive filtering). Further edit: I should mention total solar irradiance has remained relatively consistent over time (and continues to). I bring up these things because I've talked to some nutty people about this stuff in the past and those are common stepping off points into la-la land.

kaybe 6y ago
>I should mention total solar irradiance has remained relatively consistent over time (and continues to). It should be noted that the 11-year solar cycle is much stronger in the shorter wavelengths, especially below 200nm. Since that is absorbed in the ozone layer there is a change of up to 2K max in the stratopause (~50km). It doesn't really appear to propagate down, and is rather on the level of a scientific curiosity, but still. [0] (Longer-term changes than the 11-year oscillation seem to be much lower, but this is hard to determine.) [0] https://pubs.giss.nasa.gov/abs/gr08900n.html https://pubs.giss.nasa.gov/abs/gr08900n.html To the parent post: If you want to have information about UV at ground level you can look at proxy data. [1][2][3] Of course there are some complications with that as always though, and it's not that easy to interpret. But it looks like while there is variation it is mainly along the 11-year cycle. (I can't say much about the strength of the change on ground level without further reading. It's in the low percent range on top of the atmosphere, but almost all of that will be stopped in the ozone layer.) [1] https://pubs.rsc.org/en/content/articlelanding/2009/PP/b904515e#!divAbstract https://pubs.rsc.org/en/content/articlelanding/2009/PP/b9045... [2] https://www.tandfonline.com/doi/abs/10.1080/01431160500077051 https://www.tandfonline.com/doi/abs/10.1080/0143116050007705... [3] https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1469-8137.2011.03815.x https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1469-... Considering the issue of suntans, I think looking at the clothes people wear is more relevant to the question to be honest.
- rrmm 6y ago
  Thanks for the info.

by rrmm 6y ago

kaybe 6y ago

>I should mention total solar irradiance has remained relatively consistent over time (and continues to). It should be noted that the 11-year solar cycle is much stronger in the shorter wavelengths, especially below 200nm. Since that is absorbed in the ozone layer there is a change of up to 2K max in the stratopause (~50km). It doesn't really appear to propagate down, and is rather on the level of a scientific curiosity, but still. [0] (Longer-term changes than the 11-year oscillation seem to be much lower, but this is hard to determine.) [0] https://pubs.giss.nasa.gov/abs/gr08900n.html https://pubs.giss.nasa.gov/abs/gr08900n.html To the parent post: If you want to have information about UV at ground level you can look at proxy data. [1][2][3] Of course there are some complications with that as always though, and it's not that easy to interpret. But it looks like while there is variation it is mainly along the 11-year cycle. (I can't say much about the strength of the change on ground level without further reading. It's in the low percent range on top of the atmosphere, but almost all of that will be stopped in the ozone layer.) [1] https://pubs.rsc.org/en/content/articlelanding/2009/PP/b904515e#!divAbstract https://pubs.rsc.org/en/content/articlelanding/2009/PP/b9045... [2] https://www.tandfonline.com/doi/abs/10.1080/01431160500077051 https://www.tandfonline.com/doi/abs/10.1080/0143116050007705... [3] https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1469-8137.2011.03815.x https://nph.onlinelibrary.wiley.com/doi/epdf/10.1111/j.1469-... Considering the issue of suntans, I think looking at the clothes people wear is more relevant to the question to be honest.

rrmm 6y ago
Thanks for the info.