Some Christmas cheer (continued)
More light relief, for my 200th anniversary ...
Welcome to my 200th posting at UV & You! Wow. Your feedback from yesterday tells me my inaugural podcast (Christmas Day our time) went out OK. Well done SUBSTACK for making the process so easy! I’m just sad that I couldn’t get myself to look as young and unblemished on the video as I feel on the inside. One substack meanie remarked that I had a “face for the radio!” ☹
With UVI high in the New Zealand summer and our bodies overburdened with seasonal cheer, it’s time to relax safely indoors away from the ravages of UV in sunlight, with a bit more light relief. With that in mind ….
Last week’s post sparked quite a bit of interest among my colleagues.
Several readers pointed out that I’d mentioned UV-measurements at Halley Bay, when I should have said Palmer Station. The response from my old Oxford computer-guru colleague, Bob Wells, was especially interesting. He knows Halley Bay well (no pun intended) as he’d wintered-over there twice: in 1969 and 1970 (see here for more details), long before the ozone-hole reared its ugly head. He reminisced …
Halley Bay, of Joe Farman fame, is no more - it disappeared into the Weddell Sea some time ago. The British Antarctic Survey does maintain a base, simply called "Halley", in the same general area (76 S, 27 W), but it is now unmanned in winter. However, Halley (Bay) has never been on the Antarctic Peninsula! The Peninsula is (totally inappropriately) known to my rugged comrades as the "Banana Belt". Please stand corrected and have a good Christmas.
Rather too gleeful, I thought. But in the Christmas spirit I happily forgive him 😊. I indeed stand corrected. Thanks Bob.
The approximate positions of the sites are shown in the map below. Because of Palmer’s lower latitude (64.8 S), the sun rises much higher in the sky, so the UV there far exceeds that at Halley and other Antarctic sites.
Even though this year’s ozone hole never quite reached a record, it does continue a concerning trend from a UV perspective. It seems that, although the peak seasonal ozone depletion has levelled off in recent years (or perhaps even recovering apart from these occasional ‘glitches’), there does appear to be a tendency for them to persist longer into the summer. As I said in my last post, ozone loss later in the spring or early summer is more problematic from a UV perspective because it then occurs in tandem with the higher sun elevations which lead to increased UV.
Another old friend and colleague, (Prof.) Gunther Seckmeyer, from Hannover, wanted to remind me - and other readers - that the ozone hole may not yet be completely ‘solved’, as we’re moving into uncharted territory with the buildup of greenhouse gases. I agree. One of those is nitrous oxide (N2O), the third-largest greenhouse gas after carbon dioxide and methane. In the upper atmosphere, the intense UV present breaks this down to form nitric oxide (NO), which destroys ozone in a similar manner to chlorine from CFCs. For that reason, I’ve even heard talk of bringing N2O into the scope of the Montreal Protocol. But I’m sure there would be huge push-back from the agricultural community who are responsible for its increase.
My assertion that this year’s low ozone was just an outlier ‘glitch’ reminded Gunther of a joke from the mathematicians about physicists. Here it is.
How does a physicist prove that all odd numbers are prime numbers? The proof of the physicist is: "1 is a prime number, 3 is a prime number, 5 is a prime number, 7 is a prime number, 9 will be treated in a moment, 11 is a prime number, 13 is a prime number, ... you can see, the series continues, and 9 was just an outlier.
Droll! Thanks Gunther. Point taken.
Finally, a new anonymous reader (just PSG for now) made some interesting comments on my last post. In them, he pointed to a nice easy-to-read paper that explained why it took Joe Farman’s ground-based measurements at Halley Bay to discover the Antarctic Ozone Hole, despite satellite data being available for several years. Perhaps I should apologise for being a bit harsh in my assessment of it in Saving our Skins.
Happy Christmas to you, and to all my readers.
Keep those Comments coming in …