This week at Davis: 29 March 2019
How many expeditioners can fit in a weather balloon?
World Meteorological Day celebrations
To celebrate all things weather, World Meteorology Day is held on the 23rd March each year.
In Antarctica the weather dominates the environment and everything we do. For over a century, from Mawson recording wind gusts of 200 miles per hour at Cape Denison in 1912, to the mere 90 km/h recorded this weekend at Davis, weather observations in Antarctica have been recorded.
At Davis the wintering Met Team of Amy, Liam and Greg put on a Friday afternoon get-together for World Meteorology Day. The nostalgic location for this soirée was the Old Balloon Shed, recently restored to its former glory, including original red and white checked paint work, by BSS Graeme 'MacGyver' Freeman.
The venue was decorated with weather photos and charts, along with the forecasting dartboard on the wall for anyone to determine what tomorrow's weather will be! A weather balloon with cryptic meteorological hieroglyphs bounced around the room...at least until it found a stray nail. Flash coats were available for anyone who needed protection from weather jokes, and snacks were generously provided by Chef Nick.
The old tradition of balloon stuffing was performed with seven (!) people making it in before the latex couldn't take it anymore.
The Australian Bureau of Meteorology uses hydrogen to fill our weather balloons. It is much cheaper than the alternative helium and we make as much of it as we need on station. The process involves using electricity to split water into oxygen and hydrogen in a kind of reverse fuel cell. Of course, the disadvantage of hydrogen is that it's flammable, explosively so. Lots of training, care and safety equipment go into making the whole procedure safe.
We do however have a small amount of helium on station. It is used if there is an equipment breakdown, but can also be used for VIPs to make guest weather balloon releases.
So what better way to celebrate World Meteorology Day than giving one lucky expeditioner the chance to safely release a weather balloon? A competition was held to see who could pick the highest wind speed for the week. Joe the sparky, and consummate light bulb changer, got to within 6 knots of the final result of 49 knots (90km/h). Nice work!
The balloon had a bit of a head start as Joe is around 7 feet tall so the balloon reached the respectable altitude of 27,217 metres after a flight time of 1 hour 32 minutes. At that height the temperature was -55°C, humidity was 0% and the wind speed was 45 knots or 83 km/h from the west.
Joe's flight, along with the 730 other flights we do each year, goes into the computer models which produce the Australian weather forecasts everyone gets each day. It is also added to the long term climate record and helps the scientific community study the earth's atmosphere.
Davis Met Team – Amy, Liam and Greg