This week at Casey: 7 March 2014

Last Wednesday marked the final flight of the A319 for this season (Hobart — East Antarctica — Hobart FA10A&10B).

With unsuitable conditions leading up to the flight it came down to a busy time for the Wilkins team the night before the flight was due. The runway needed to be groomed to cover up the bare blue ice that had appeared as a result of the persistent strong winds in this part of the world.

As the day dawned the final preparation were made and the Wilkins boys enjoyed the last of Kim’s great cooking. While we ate Kim took out pastries from the oven and put the finishing touches to a delicious carrot cake specially made for the summer crowd that were slowly making their way over the 70 kms of ice between Casey and Wilkins — an early start for them leaving at 0300 (just after the departure of the plane from Hobart)

The crisp minus 17°C temperatures at Wilkins heightened the wintery Antarctic feel that they would all be missing soon enough and reminded those of us that would be staying for the winter of its approach. With the runway and lights checked and ticked off all systems were deemed go by Jeff the Aerodrome Manager.

The plane approached and made a stunning flawless landing on the freshly prepared surface. Only one last minute arrival, Kevin our Met Tech for the winter made his way towards the waiting vehicles. The departing summer crowd like a mass of yellow and black wasps made their way to the plane and it was with mixed emotions that we farewelled them — our friends and work colleagues of many months. Most eager to see their families and loved ones, but loath to leave this fantastic place.

The doors were shut, the steps pulled away and immediately the sleek plane started to move, engines shifting gear to a higher pitch as she headed to the runway to take off into the wind with the sun shining starkly on the vivid white surface of this small section of the East Antarctic ice sheet.

Safe travels and see you in the Spring!

The month that was…

Stormy, fresh, breezy, squally (my favourite), blustery (my other favourite), blowy, brisk, wild, unsettled… I think you see where I’m going. February was a windy month, record breaking in fact. Other than that not much to write home about, temperatures were about average despite one particularly cool night. A shade sunnier, a drip drier and oh, of course, there were three blizzards; above the norm and somewhat related to the ‘windiness’ of the month.

We had an even mix of positive and negative temperatures for our day time maximums, the monthly average just positive at 0.1°C, a meagre 0.2°C above average. While our now ‘dark’ overnight minimums, averaged −4.9°C, also 0.2°C above the norm. The hottest day of the month was on Feb 20 topping out at 3.7°C; the lowest 24hr minimum on Feb 26, giving us a taste of what’s to come, a chilly −14.1°C, shy of the record February cool of −18.0°C.

What really had us up here in Met holding onto our beanies however, and not just because were jumping up and down with excitement, was the record breaking blow. The maximum wind gust of 187 kph recorded during a blizzard on Feb 19; was the strongest wind gust recorded on a February day, well eclipsing the previous record of 176 kph in 2004. Not only was this the strongest wind gust recorded at this current Met site (since 1989) but also stronger than the 167 kph in 1986 which was recorded at the old Casey site, ‘the tunnel’, active from 1969–1989.

But wait there’s more… not only did we have a good blow on Feb 19, we had 3 official blizzards for the month (Mean wind > 34kts for 1 hour, Visibility < 100meters, Temperature < 0.0°C). Contributing to 17 days of strong wind (recorded mean wind of 22–33 kts), 11 days of gale force winds (recorded mean wind of 34+ kts) and 8 days of blowing snow (snow raised and blown above eye level). The net result was a recorded wind run for the month of 22560 kms (how far a parcel of air would have travelled). That’s a daily mean of 806 kms, another record and well above the previous record windy February of 756km.

We did also have 13 ‘snow days’ for the month, though just the 7 rain/snow days where 0.2mm or more was recorded in the snow gauge, giving us a monthly total of 6.6mm (snowmelt minimum); which is less than half the miserly monthly average of 15.2mm. Mind you there was also 8 days of blowing snow (during such events the snow gauge is brought inside so as not to mix falling with blowing snow). In amongst the snow, blowing snow and blizzards we actually had some sunshine too, 5.2 hours was the daily average, 0.4 hrs above the average.

CHILL from the Casey Met Team

Last weekend four Casey expeditioners made the long three hour journey to the Browning Peninsula, the first recreational trip of the winter. Rob, Ian, Grant and Steve made their way by Hägglunds to the hut of the same name perched on this headland to stay overnight. They hoped for improving weather to allow a visit to one of the southern elephant seal (Mirounga leonina) wallows where these enigmatic creatures come to lie and moult (shed their outer skin all at once) before returning to the depths of the southern ocean.

Browning Peninsula is the site of numerous known and studied wallows (historically since 1957). Here the seals pile next to and on top of each other in steaming, squirming and reeking heaps, barely tolerating each other yet squished together as if their lives depended on it.

Tagging and census studies have shown that the predominantly male populations of these wallow hale from the breeding beaches in the Kerguelen Group (Kerguelen and Heard Islands) and from Macquarie Island, having travelled distances of ~2500 and 2800 kms respectively from their birth beaches (van den Hoff, J., Davies, R., and Burton, H., 2003).

Our team enjoyed the encounter and came back with some great shots as the images below show.