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r930 | 3 years ago

NASA has interesting Ozone monitoring data for those interested.

https://ozonewatch.gsfc.nasa.gov/

Those of us in the lower southern hemisphere get hit pretty hard with UV radiation in spring (Sep-Nov).

discuss

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stephen_g|3 years ago

Yeah, we tend to get a triple-whammy down south. I recall reading that the tilt of the earth, as well as atmospheric pollution make even more of a difference. If I recall the figures correctly, the UV hole can increase UV by ~3% in the southern hemisphere compared to the northern hemisphere, but the fact we tilt slightly closer to the sun in summer than the northern hemisphere makes 6-7% difference, and the fact that there is far less atmospheric pollution (aerosols, etc. that absorb some UV) in the south makes another ~6%. So even in summer when the UV hole is at its minimum, at the same distance from the equator you can have something like 12-14% more UV exposure than the northern hemisphere in summer.

It's ironic that better pollution controls, while causing many health benefits, will potentially make things worse for skin cancer in the northern hemisphere by gradually increase the UV doses, so you all are going to have to get better at sun safety or melanoma will become a much bigger issue there.

thaumasiotes|3 years ago

> but the fact we tilt slightly closer to the sun in summer than the northern hemisphere makes 6-7% difference

How could that be a fact? Axial precession (a) has a period that is much longer than a year, meaning there is no systematic difference between the northern and southern hemispheres; and (b) has a period that is MUCH longer than a year, meaning the difference between the northern and southern hemispheres in the same year is negligible.

https://en.wikipedia.org/wiki/Axial_parallelism#Earth's_axia...

https://en.wikipedia.org/wiki/Axial_precession#History

hackernewds|3 years ago

Are you implying that pollution will decrease the instances of skin cancer perpetuated by solar UV?

dietr1ch|3 years ago

The sun has been really strong since the early 2000s. It's a shame that the Southern hemisphere got that affected given it probably produced less than 20% of the damage.