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After 29 years, the chief of Australia’s Antarctic Local weather program is hanging up his ice drill.
“We’ve simply constructed an airport!”
Admiring the view of a two kilometre-long ski-runway along with his deep-field Antarctic colleagues, it was an surprising achievement for local weather scientist Dr Tas van Ommen, in late 2013.
Tas and a small group of Australians and French had spent the previous two weeks traversing the windswept Antarctic icecap, to a website referred to as Aurora Basin, 550 kilometres from the closest station, to arrange for an ice core drilling camp.
The runway would enable for a global group, led by Australia, to fly to the positioning a couple of days later and drill greater than 500 metres of ice containing a local weather document relationship again 2000 years.
“Two thousand years offers us a pleasant lengthy interval to take a look at the local weather, earlier than human interference started with the emission of carbon dioxide into the ambiance,” Tas stated on the time.
Ice cores include gases, particles and different chemical parts which might be trapped in snow because it falls and compacts to type ice. This chemistry gives details about the temperature below which the ice shaped, storm occasions, photo voltaic and volcanic exercise, sea ice extent, and the focus of various atmospheric gases over time.
In addition to its scientific worth, Aurora Basin was a reconnaissance operation for a extra formidable future aim, to drill an ice core with a a million yr local weather historical past. Such a core will assist clear up a long-standing thriller in local weather science.
Stellar beginnings
Wanting again on his 29 yr profession with the Australian Antarctic Division, it’s clear Tas has by no means been one to shrink from a problem.
As a self-confessed “science geek” rising up on the north-west coast of Tasmania, Tas stated his greatest likelihood to get into the occupation was to do a instructor studentship, to assist pay his approach by way of college.
A critical automotive accident delayed his research, and his life, for a yr, however he finally accomplished an Honours diploma in radio astronomy and a Diploma in educating.
“I spent a yr educating in Launceston however it wasn’t my pure habitat,” he stated.
“Nonetheless, the coaching was pivotal in my later profession as a result of it taught me to consider my viewers and to all the time be ready.”
Tas returned to the College of Tasmania to finish a PhD pulsars (a kind of star), utilizing the radio telescopes at Cambridge (Tasmania) and Parkes (New South Wales) – dramatized within the film The Dish.
“After that I bought a job with NASA’s Jet Propulsion Laboratory, utilizing their Deep Area radio telescope to measure distant objects past the Milky Method galaxy,” he stated.
“It was an thrilling place to work, however Los Angeles wasn’t actually my pure habitat both.”
After 18 months he returned to Tasmania and utilized for an “odd job doing one thing with ice cores”.
“I didn’t know loads about ice cores, however I offered myself within the software as a great physicist,” he stated.
Whereas he was ready for an interview, coincidentally, his future mentor and colleague, eminent Antarctic physicist and glaciologist, Dr Vin Morgan, appeared.
“Vin was giving a lecture on the Launceston museum on the Regulation Dome ice core. So I went alongside, and that was the place I came upon what I used to be going to do for the remainder of my profession,” Tas stated.
Halcyon years
Tas moved to Hobart in 1994 to take up the place as a glaciologist on the Australian Antarctic Division, alongside Vin Morgan.
It was excellent timing, as drilling of a 1200 metre-long ice core from Regulation Dome had simply been accomplished. The core supplied a local weather document extending again 90,000 years, and a few years of scientific evaluation and discovery that proceed in the present day.
“They have been good, productive years the place we have been churning by way of the ice core, however it meant that I had no must go to Antarctica for the primary 10 years of my employment,” Tas stated.
The core gave Tas one of many highlights of his profession, when its chemistry revealed a hyperlink between snowfall at Regulation Dome, and rainfall – or extra particularly drought – in Western Australia.
“After we checked out long run meteorological information of south-west Western Australian rainfall, we noticed low winter rainfall when the snowfall at Regulation Dome was excessive,” Tas stated.
“It was obvious that there have been giant scale climate methods within the Southern Ocean that join Western Australia and Regulation Dome, and that was most likely one in every of my most vital findings.”
By means of this discovery Tas and his group have been in a position to establish the seemingly underlying position that local weather change performs within the long-term drought in Western Australia, with vital implications for water catchment administration in Western Australia.
“The Regulation Dome core was good to me. It got here on the proper time,” Tas stated.
ICECAP
Additionally properly timed was an surprising dialog with College of Texas geophysicist Dr Don Blankenship in 2007, initially of the Worldwide Polar 12 months. Dr Blankenship proposed a collaboration to fly line surveys throughout Antarctica, mapping the bedrock on which the ice sheet sits.
“I put the proposal to our Director, Tony Press, as an awesome thought for the Worldwide Polar 12 months and he stated ‘make it occur’,” Tas stated.
Dr Press’s help led to a global collaboration referred to as ICECAP that continues in the present day. Over 11 seasons the group has mapped greater than 700,000 line-kilometres.
The mapping knowledge has revealed that enormous elements of the East Antarctic ice sheet sits on bedrock under sea stage. Way more than anybody had anticipated.
“If you happen to have a look at all of the ice sheet modelling work that’s gone into the Intergovernmental Panel on Local weather Change stories, and numerous papers beside, all of them relaxation on understanding the bedrock, and the ICECAP work is key to this in East Antarctica,” Tas stated.
“I’m proud we bought ICECAP up and operating, and once more it was a case of being in the correct spot on the proper time.”
Antarctic connections
In October 2004 Tas had his first alternative to ‘go south’ on icebreaker Aurora Australis.
“I can nonetheless keep in mind being on the bridge at night time, with the lights out in entrance as we nudged by way of the pack ice, with snow falling overhead. I used to be caught then,” he stated.
Since then he has been on six analysis expeditions and 7 VIP flights to Wilkins Aerodrome, utilizing his educating expertise to clarify the significance of Antarctica to local weather change analysis.
“It’s actually vital to construct connections between researchers and policy- and decision-makers. You possibly can see the penny drop once you present them an ice core and clarify what you do. We will nonetheless keep away from a number of the distress of local weather change if we will get the coverage traction we’d like,” he stated.
Icy grail
Previously decade Tas and his group have turned their consideration to what’s thought of the ‘holy grail’ of ice core science – an ice core with a local weather historical past of a couple of million years.
Amongst different issues, this document will assist scientists perceive why virtually a million years in the past, the cycle of ice ages shifted from a daily 41,000 yr cycle to an ice age each 100,000 years.
A number one idea is that declining atmospheric CO2 ranges have been the reason for the longer, colder ice ages. The million yr ice core document will present the important CO2 document to check this idea.
The work of ICECAP and at Aurora Basin had indicated that Little Dome C, about 1200 km from Casey analysis station, would seemingly have such outdated ice. However to get there, Australia wanted to reinvigorate its traverse functionality.
“Aurora Basin taught us which you could’t do massive inland actions with out floor journey,” Tas stated.
Final season Australia’s first heavy traverse in 20 years navigated a path to Little Dome C and established a website for drilling to begin on the finish of 2023.
So how does Tas really feel about leaving as a brand new chapter in local weather science is starting?
“I’m thrilled with the group we’ve to hold on this work. We’ve wonderful folks setting it up for scientific success, and we’ve a outstanding group doing an unimaginable job on the traverse,” he stated.
Tas will proceed in his position as co-chair of the Worldwide Partnership in Ice Core Science and on the advisory board for the European effort to drill one million yr ice core – taking place in tandem with Australia’s efforts.
However he’ll miss his colleagues.
“For a man who began out being mad eager on something scientific, I discovered that what actually issues is doing stuff with folks,” he stated.
“That communal achievement, in deep-field Antarctica and on station, was one of the best.”
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