Multi-coloured aurora, April weather highlights and reflecting on our missing furry friends — all part of this week at Casey.

Multi-coloured aurora

Here at Casey over the last month we have seen quite a few auroras caused by solar winds carrying charged particles that collide with the magnetosphere over our planet.

These particles follow the magnetic field lines at the north and south poles where they are funnelled into our lower atmosphere. The result is energy released in the form of light, the bright green and red colours being caused by the various elements in our atmosphere. 

April weather highlights

A great start to the month with my birthday, a Hobbit feast followed by an unexpected journey. Oh, the weather is what we’re talking about. What weather! It was considerably colder, less than expected snowmelt (rainfall) and very much less windy than expected, in short below average. This translates as far fewer snow days and strong wind days but most distressingly, no blizzards. What’s going on there? We’re supposed to be in Antarctica! Not the African savannah watching hippopotami wallow in the diamond dust.

Just like facing down a charging hippopotamus, ‘When’s the next blow?’ was the terrifying chortling of the crew that had us in meteorology quaking in our baffins. The cause of the crew’s unrest? The boring weather, typified by not recording a single blizzard for the month when we normally average three and a half. If last month’s wind was “barely enough to lift a hair on a balding head”, then a maximum wind gust of 133 km/hr and just the 11 strong and three gale force wind days, compared to the average of 15 and 10 respectively, wasn’t doing much to part that comb over. The net result, a 512 km average daily wind run, a significant 121 kms below average.

But wait, there’s more! Not only was the wind and weather well below average, so were the temperatures. Our daily maximums averaging −10.0°C, 2.4°C below the norm, while the overnight minimums averaged −17.0°C, a similarly 2.3°C below average. The warmest day of the month was on the 4th, reaching −1.5°C; the lowest 24hr minimum on the 14th bottoming out at −23.9°C. Alas for all this below-average weather, no records were to be broken. About all we can hang our hat on after trolling through the climate stats, it was the 5th coldest April for both maximum and minimum average daily temperatures. Not even on the podium with that one!

To continue the below par story, our 12 snow days, four less than average, delivered a miserly 6.2 mm (snowmelt minimum), well shy of the monthly average of 20.6 mm. Nothing else of note occurred, so to find that little ray of sunshine and finish on a positive, we did have an average of two hours of daily sunshine, which was spot on. That positive won’t last, however, as we move into May, the second least sunny month of the year. Midwinter is fast approaching.

So here’s looking forward to a dark, cold and wet month.

Steve B.

Adélie penguins

It has been a solid month since my last Adélie penguin sighting, so it seemed only appropriate to relive the fond memories of our feathered friends as we while away the months until they're gracing our doorstep once again.

We arrived at Casey in November last year, and were greeted by a little Adélie penguin running around station on the very first day. From that day on you never had to look too far to find one as they are, by far, the most inquisitive animals I've ever seen. Once they spot you, whether you're twenty meters or two hundred meters away, they run, slide and waddle over as quickly as possible just to check out what you're up to. 

As summer got into full swing I was fortunate enough to accompany our Antarctic scientists to some of the Adélie breeding grounds on the nearby islands. The Adélie penguins had collected numerous pebbles of all sizes to build little stone nests to protect their newborn chicks. The parents take turns looking after the chick, while the other heads off to catch fish, swim, and have awesome penguin fun.

Over the last couple of months the juvenile penguins have been moulting their baby feathers before heading out to sea. At this point they had left the protection of the nests and instead, remained in small groups ranging from a mere couple to over 30 moulting teens. And boy are they grumpy! Where the older penguins are fun loving little critters, these guys are suspicious and constantly squawking, not even posing for a proper photo.

Now that the sea ice is growing and getting thicker with every passing day, it seems that the last of our favourite feathered friends have departed Antarctica for the winter. Farewell buddies.