🚀 go-pugleaf

Jonathan Shanklin <j.shanklin@bas.ac.uk> wrote:

>I can vouch from personal experience the link between low ozone values
>and increased uv having just returned from the Antarctic.  When I left
>the UK in early November data was suggesting that the ozone hole was
>nearly over.  Whilst carrying out cargo work at Port Lochroy on a day
>with much cirrostratus and thin altostratus most of the ship's company
>suffered sun-burn to a greater or lesser extent, even those wearing
>blocking cream.  A subsequent radiosonde flight revealed low
>stratospheric temperatures suggesting that the ozone hole had returned
>and on my return to the UK inspection of satellite imagery showed that
>the ozone hole was over the area at the time.

This is contrary to my own experience.  Whilst visiting Cradle
Mountain in Tasmania during January, I experienced an unusually clear
day, just some cirrus clouds.  On that day, Tassie papers were
reporting extreme UV, and on returning to Sydney, I checked the latest
satellite imagery, which showed that the breaking up of the ozone hole
was forcing ozone poor air north over Tasmania.

I spent over 6 hours in the sun whilst hiking, with only a cap on, and
no sun-screen (I didn't expect the sunshine).  I did not get burnt at
all.  If I had spent that amount of time in the sun in Sydney, then I
would have looked like a beetroot.  Despite ozone depletion, I am
safer from UVR in Tassie than in Sydney. ie ozone depletion does not
necessitate increased likelihood of UVR induced cancer.

I am also a keen skier.  When skiing in the Snowy Mountains, between
Sydney and Melbourne, if the sun is out I lather on the sun-screen and
cover up.  This is not because the UV is high, but because snow
reflects UVR very efficiently, and will increase exposure manifold.
Whilst I do not argue that UVR does not increase in Antarctica, I
humbly suggest that your experience in Antarctica, Jon, and the
spurious statistic which suggests UV levels are the same as in San
Diego, may be due to reflected UVR, rather than solely due to
increased UV-B due to ozone depletion.


...Greig