In a small green laboratory perched on the rocky volcanic southern peninsula of Ross Island, Antarctica, there’s a space waiting for a new shiny, hi-tech Christmas present.
It’s called a Fourier Transform Spectrometer, or FTS, and right now it’s in six boxes on its way south from NIWA’s Lauder Atmospheric Research Station in Central Otago.
It weighs about 300kg, costs about $NZ500,000 and is set to take over duties from the incumbent FTS system affectionally known as the “old beast” that has more than served its time.
The new FTS takes high precision measurements of important greenhouse gases, ozone and ozone depleting gases in the atmosphere. NIWA’s measurements began in 1992, making them the longest running time series of this type in Antarctica. It’s also the only FTS on the continent – and one of only 5 in the southern hemisphere - that feeds into the Network for the Detection of Atmospheric Composition Change (NDACC) which means it has an extremely important role in global atmospheric measurements. The measurements from the FTS are to be used in NASA and ESA satellite validation activities and also assist in climate-chemistry modelling work conducted at NIWA.
NIWA researcher Dan Smale said the old FTS has had a hard life and should really get a medal for long service.
“When it first went to Antarctica it went to the South Pole by mistake where it sat outside for a long time, before being sent back to the Arrival Heights laboratory. It’s done a sterling job for us. Mechanically and optically it’s still very good but the electronics are now outdated and unreliable “
NIWA researchers John Robinson and Dave Pollard are flying to Antarctica this week to install the new 3rd generation FTS. Once that’s up and running, it will run in tandem with the old one so data can be compared before continuing recordings with the new instrument.
“We want to know how the new instrument is trending over time. Is it stable? Will it still be saying the same thing in three years’ time? We’re very lucky the old beast is still working and our planned replacement is not too late to make these comparisons.”
Once the NIWA team head home, an experienced science technician from Antarctica New Zealand will continue making comparison measurements until the sun goes down in March. This will require a daily commute from Scott Base to Arrival Heights, sometimes in blizzard conditions.
“Then we’ll go back this time next year, start the old beast up again and do a few more spot measurements. The more comparisons we can make, the more confidence we will have in the new instrument,” Mr Smale said.
Eventually the old FTS will come back to New Zealand and may yet have more life to give, depending if the electronics can be replaced.
Meanwhile, NIWA’s Dobson Spectrophotometer – which is the granddaddy of all ozone measuring equipment and described by Mr Smale as bulletproof and awesome – is also on its way back to Antarctica after having some much-needed maintenance. The Dobson instrument measures ozone and the NIWA machine was built pre-1960.
It has been in Antarctica since 1987, having survived a flood in Invercargill before heading to Scott Base.
“It’s a classic whose beating heart hasn’t changed at all. The ingenuity to take such measurements in an age pre-computers is amazing to behold.”
