This week at Macca we celebrate Vicki’s birthday, take a look at what we did for National Science Week and explain what happens in the Macca Clean Air Lab

August Birthday

Thanks goodness for Vicki’s Birthday in August. We haven’t had any birthday cake since Chris B’s in June — seems an awful long time.

Annette as per usual outdid herself yet again with a two-layered masterpiece — the bottom half of the cake a rich chocolate fudge brownie — laced with almonds and the top half a creamy chocolatey mousse topped with a pressure ridge of chocolate shards — not to mention the crystallised violets for decoration.

Needless to say it didn’t last long split among 14…

Science Smoko

For National Science week we turned the Macca Mess into the Macca Laboratory and made science the topic of conversation along with our cappuccinos and sausage rolls.

We dressed the part then worked our way through the ‘Brain Break’ questions and the various inter-active displays set up around the room.

On the bar our SCTO Norbert had several displays from his area of expertise set up — these included a length of fibre optic cable bending light through its coiled length; an oscilloscope through which our voices were visually displayed as wavelengths; and an amazing machine (multimeter) that apparently read our aura if we held a probe in each hand!

Station leader Ali had set up a geology display illustrating the many forms that quartz takes from opal to obsidian; the reaction that occurs when (citric) acid is dropped onto a piece of calcite (calcium carbonate); and the obvious double refraction through a clear calcite rhomb.

Station Mechanical Supervisor Chris had several bottles of brightly coloured antifreeze (glycol) which we tested by placing drops on his refractometer — an amazing handheld device which determines the refractive index of a liquid that is then be scaled to give you the flashpoint and other thermal properties. 

Then there were the marshmallows (2015–2017 vintage) and bamboo skewers used to make molecules of water and salt, plus the brightly coloured ‘edible’ (but not necessarily delicious) slime.

Outside in the sunshine (all too brief) FTO Rich demonstrated the incredible strength of a length of kernmantle climbing rope by getting Tim and Chris B to suspend themselves through a foot loop (only a few inches off the ground), then cutting through the woven external sheath of the rope and gradually severing the many twisted strands of the core until only a few remained. It took Rich himself jumping on the rope to finally break it giving us all a great deal more confidence in the ropes we use than we had before.

We finished out science focused day with the Macca premier of the winning SCINEMA movies for this year — with popcorn of course. 

Macca Clean Air Lab

There is a lonely little building, guarded by ellie seals, that stands on the west coast of the Macquarie Island isthmus. Kept separate from the station, and all the air polluters, the clean air lab busily gathers data 24 hours a day, seven days a week. The clean air lab is home to several ongoing science projects run with BOM staff including the CSIRO GASLAB experiments and the ANSTO high sensitivity radon detector radon monitoring.

As a part of the CSIRO’s atmospheric research, the GASLAB (Global Atmospheric Sampling LABoratory) maintains its own air-sampling network. The network has global coverage but focuses on the Southern Hemisphere, including Cape Grim and sites further south such as Macquarie Island and Antarctica. Linked to other international networks, the GASLAB network is a part of a coordinated and collaborative effort to study the global atmosphere. This includes measuring gases like Carbon Dioxide (CO2) and Methane (CH4) that are associated with global warming.

The Bureau Met Tech (Angus) takes primary responsibility for maintaining the GASLAB equipment on Macquarie, fixing any faults and sorting out computer issues. For the equipment like the PICARRO analyser this includes turning on and off calibration cylinders, noting unusual activities around the building, and ensuring that CSIRO staff back in Melbourne, Australia are able to communicate with the computers.

We (BOM Trio) are all involved in the second GASLAB experiment that is taking fortnightly air samples. Every fortnight we use the Sherpa Model 70 Sampling Unit to fill two 500 ml glass flasks with air, on a day that the wind is cooperating. To ensure we have air samples “fresh from the Southern Ocean” and uncontaminated by station operations we have strict wind direction and wind speed requirements for taking air samples. The glass flasks are then carefully repackaged in their foam-lined cases and sent back to Australia for analyses in the CSIRO laboratories.

The 2000 year greenhouse gas records from Cape Grim and Antarctic ice sites highlight the human imprint on the atmosphere since ~1800 AD. The earlier ‘pre-industrial’ period reveals smaller but significant variations in greenhouse gas concentrations. They provide important information about natural exchange processes involving the atmosphere and linked reservoirs, such as the oceans and terrestrial ecosystems.