The University of Maine website climatereanalyzer.org has a plethora of data visualizations, among them a display of 2 meter temperature anomalies.

The image of Antarctica today is below, with a green circle added by me:

2m temperature anomalies over Antarctica, Sep 19, 2023

The circle shows a warm spot approximately covering the Ross Ice Shelf. The bright maximum temperature deviation in the center amounts to roughly 28K. A temperature map shows that there is a spot on the shelf that's as warm as 0°C, still in the Antarctic winter.

Other incursions of warm air are visible as well.

On other days the air may not be quite as warm, but I commonly see "incursions" of air much warmer than average. I'm aware that the extremely dry and cold air over Antarctica is prone to larger temperature oscillations than usually observed in other places. Still, 28K seem quite extreme.

On the other hand, nobody seems overly worried by the current state of affairs.

This is in contrast to some extreme events that made the headlines outside the professional community in the past years. One example is the off-the-charts temperature record in March 2022. I was wondering whether there is an underlying increase in events which raise eyebrows in the professional world but don't reach the general public, and whether an observation like this one is an example.

Therefore I'm wondering how common such a situation is. As an idea of what I'm asking:

  • Have such events been observed 50 years ago? (Did we even look?)
  • If yes, have they become more frequent?
  • If yes, are you worried? ;-)
  • Is it within the prediction range of the models? Upper range, lower range of the predictions?
  • If not, are you worried?
  • $\begingroup$ In the northern hemisphere we've had up to 10 degree fluctuations from the arctic norm sitting there for days in at least the last the last years, since I joined the stack exchange and asked about this stuff as well.. $\endgroup$ Commented Sep 19, 2023 at 18:44
  • $\begingroup$ KarstenHaustein's site has unfortunately had a serious issue... but you can see a loop from early August with what appear to be near/to +20 and -20 rotating around the continent back then too. $\endgroup$ Commented Sep 20, 2023 at 7:35
  • $\begingroup$ I chose somewhere quite variable from the US: Bismarck ND... for March 20th, their average high is 33F, their record 70F (in 1910). Their normal low is 21F, their record -14F (in 1875). So looks like +/- 20 Celsius does happen. So it may well not be untouched in scale, but it's just a question of how often such things are happening, as you say, which I don't have a quick answer towards. Interestingly it looks like from trying a few sites around the US, observed range tends to be quite a bit greater at the spring equinox versus the fall one? $\endgroup$ Commented Sep 20, 2023 at 7:47
  • $\begingroup$ @mmt10 Well, I'm not sure how to word my question better. I have no good access to past climate recordings and I'm no meteorologist or climatologist, so I'm lacking data and the ability to interpret it. I'd be happy for somebody to say "20K is no big deal, happens all the time, the Antarctic is weird" or "yeah, we are all biting our nails in the simulation lab because if this continues for another 20 years the Ross Ice Shelf will collapse and the glaciers will slide into the sea and NYC will flood, it is literally off the charts and we can't model it". $\endgroup$ Commented Sep 22, 2023 at 13:01
  • $\begingroup$ @mmt10 Or, maybe of course, something more sane like "this incursion of warm air is a sign of the polar vortex weakening. Such events have been observed ever since we started looking but they have become more common in the past 20 years or so which is exactly what our simulations predicted for the level of global warming we are measuring." $\endgroup$ Commented Sep 22, 2023 at 13:04


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