This week at the station
This week at Mawson: 25 May 2012
Aurora! At Mawson it's become similar to the call of "Eureka!" in the gold rush days. Most will find a window and try to peer through the reflections caused by the double glazing with hands cupped over foreheads to see if it is worth getting dressed. If you can see any "colour" through the tinting it's usually reasonably bright and worth sticking your head out the door to then check if you need your camera.
Unfortunately, the best time of the night for viewing is usually about 2AM when the Sun is nearly opposite to Mawson (please ask your friendly neighbourhood astrophysicist for an explanation), which makes the art of forecasting quite important. Firstly, no cloud, so a check of the weather forecast (and a quick peek outside) is needed. Then a check of space weather forecasts: solar wind, recent solar activity, magnetic field strength and direction. After all of that, and regardless of what magical number you end up with, set the alarm for 2am and poke your head outside as it’s probably changed.
In “simple” terms the aurora is caused by charged particles from the sun, carried by the solar wind penetrating the Earth’s magnetic field and reacting with gases in the upper atmosphere. The gas determines the colour of the aurora, nitrogen will produce blue or red and oxygen will produce green or brown-red, with green auroras most common. The aurora occurs simultaneously in both the northern (aurora borealis) and southern (aurora australis) hemispheres in a very similar pattern (an oval around each of the poles). Because of the shape of the Earth’s magnetic field, the aurora is most visible at high latitudes and will be visible in Australia when the effect is strong enough, usually following a solar flare.
"There must be an easier way", I hear you ask. I've setup my "Frankencamera" with timer to take a picture every 30 seconds. As the standard battery lasts for only 2-300 shots I’ve taken it apart and hooked up an external battery. With a little manipulation of the 2000 odd photos taken overnight, a time-lapse of the activity can be made as well as capturing some great photos by themselves. It sounds like cheating but when it's -20C outside, windy and 2am, it's much easier. There are risks to leaving your camera outside from sunset to sunrise as on one occasion, the lens was filled with snow when I went to retrieve it in the morning (with some careful blowing, heating and drying it is now working again).
The aurora is a mesmerising phenomenon, with usually green “curtains” of light that move and dance around quite quickly as if a breeze was blowing them around, bright enough at times to illuminate the ice with a dull green before fading away completely. It’s something that never loses its charm or fascination.
Auroral Grandeur by Mike Manion (Electronics engineer, Mawson 1994)
As the dark of night intrudes our soul,
We watch agape the distant void.
With dreams and knowledge of mortal through,
We ponder our stage in meagre play.
Our hearts and heads in solemn keep,
Suppress the echoes of a lonely beat.
We gaze in wonder of a distant realm,
And shiver in the light of frozen time.
As we mine our thought in questful bid,
To extract explanation beyond a myth,
We feel a quickening not of this world,
And focus with study the starry ensemble.
With swift and bounty silence,
There bursts a crimson from the ether.
With a celestial drape of halo green,
It writhes in passion of reverant beauty.
In shimmering veil of feathered loft,
The aurora descends in a radiant furore.
Like colourful serpents in a titanic struggle,
It pulses and ripples in surreal enchantment.
With a seductive evanescence that pervades all being,
We are drawn inexorably to this electric synergy.
The turmoil of colour extends and invitation,
Our spirits soar in seraphic effigy.
With sudden retreat to nebulous blotches,
We gaze through the vestige of the auroral diminuendo.
Gone is the colour that festooned the heavens,
And again just start crowd the vacuous sky.
As the cool antarctic chill enshrouds the night
Our spirits remain aloft the introspective glance,
And we are reminded in full as we turn in the epoch
That in nature transience is born to all.
Two tradies and two photographers headed out into the wilds to do some essential hut maintenance repairs. First stop was the Mt Henderson hut where the intrepid workers battled through whiteout, blowing snow and gale force winds to park the Hagglunds, unpack and enter the hut. First job on the list was the essential repairs for the toilet. Someone, somehow had broken the cosy cheeks. Chris used contact glue to stick the two sections of blue polyurethane foam together and with the addition of special silver toilet seat tape from Mitre 10, the toilet seat was ready for use.
After the trauma and hard work of watching the sunset through the snow at 3.30pm, an enjoyable evening was had by all.
The next day after the traditional civilised breakfast of toasted bacon and cheese sandwiches, we packed up and headed over to Rum Doodle hut.
Two items were on the list for Rumy. A new window for the inside cold porch door, cause those without a head torch have been know to bumble round in the cold porch for quite some time before finding a door, whether it was the door they wanted is another question. The second job required the skill of a plumber to take out the old oven and install a shiny new one.
By dinner time the work was completed, with candlelight streaming though the window into the cold porch everyone felt safe to venture out to view the aurora. Dinner was of course, Fray Bentos pies, as that is the only way to christen a new oven in Antarctica.
Skating on thin ice
One guarantee in Antarctica is that you can usually find some ice about. If you’re lucky it’s smooth enough to go ice skating on. Since the first grease ice formed in the Harbour at the start of March there has been much staring out the window and conversation about the quality and thickness of the ice. By the middle of April, the ice was thick enough and Bob finally gave into the begging and tears and gained permission for us to skate on the Harbour.
There are several types of skates being used by our sporty expeditioners, purchased and sent to Mawson for just such occasions, and likely to be very useful back in Australia.
There is the ice hockey skate, for those of some skill, and the multiskate which straps on over the boot. You have to have a small enough boot or foot as we discovered some of the issued AAD footwear is too fat. But after some adjustments and much testing is was concluded that the multiskates are preferable. Having the longer blade and designed for cross country and outdoor skating in Europe, they are able to travel over the lumps and bumps in our ungroomed ice and thus you spend more time upright and less on your butt. There is also the multiskate and ski pool combination, for those who have cross country skied previously or who just can’t keep their balance. However, the poles can hinder the speed of the uncoordinated.
We have started the Mawson pairs ice dancing team and have put in the Zamboni order, eagerly anticipated for next winter.
The old exploding water trick
It is a little known fact by those who haven’t been south before that below about -25 degrees Celsius, boiling water will turn into steam when thrown outside. This is much talked about as a fun day out by those who have tried the exploding water trick and only half believed by the ‘newbies’.
This week temperatures at Mawson went down to -30.8°C overnight and were around -28°C when the sun rose at 10:45am in the morning of 22nd May. Thus conditions were perfect for some hardy expeditioners to risk frostbite and investigate this scientific curiosity.
You can check the Internet for the detailed explanations for this phenomenon, but the effect occurs because as the boiling water is thrown into our cold, dry Mawson air, the surface area of the droplets is increased and the water evaporates and forms a cloud of ice and supercooled water droplets.