The Argo float was one of the more established ocean observing technologies that formed Australia’s new Integrated Marine Observing System in 2006. The international Argo program brought with it nearly a decade’s worth of experience in technological development, operational experience in the oceans and well established international links. Argo also brought the expertise of Dr Susan Wijffels, an oceanographer with CSIRO’s Marine and Atmospheric Research Division (now CSIRO Ocean and Atmosphere).
Dr Wijffels’ recalls the advantages joining a national collaborative ocean observing program, such as IMOS, provided the Argo program.
“IMOS put Argo into a national framework that recognized the value of ocean observing. Before the NCRIS funding the Argo program in Australia was vulnerable as it was spread across a number of agencies,” says Dr Wjiffels.
“The NCRIS funding doubled the scale of the Argo program in Australia, formalising partnerships that were established in operating the program, for example between the CSIRO, the ACE CRC and the Bureau of Meteorology.”
The NCRIS funding brought about a profound shift in the marine science community in Australia. Prior to IMOS agencies and institutions would compete against each other for funding.
“IMOS facilitated and rewarded the inter-institutional collaboration which is absolutely vital for observing the ocean,” says Dr Wijffels.
Another important advantage provided by NCRIS was that the actual data streams were recognised as the infrastructure that needed to be maintained, rather than the observing equipment itself.
As mentioned, the international Argo program pre-dated IMOS, operating since late 1999 and at the beginning of the IMOS era, involved 15 float-deploying countries. However, over the first decade of IMOS, improvements continued to be made.
Dr Wijffels recalls the most important improvement in the last ten years of Argo in Australia was actually making the floats work for longer in the hostile ocean.
“We worked on opening and checking them to understand the technology. We wanted to ensure we got the maximum value for every float purchased.”
“The international Argo network provides the links to make sure that any problems encountered are shared. This has helped the Argo program to stay at design density and to ensure data quality remains high.”
“In fact, the quality of the data set for climate studies has surpassed our initial expectations,” notes Dr Wijffels with pride.
The ocean is a globally connected system, and marine observing is an international endeavor. The investment through NCRIS into IMOS as the national marine observing system has successfully provided both an independent capability to assist Australia in managing its own marine estate, and a significant attractor of international collaboration and co-investment.
Dr Wijffels says this has been recognized by the global community.
“IMOS catapulted Australia to the level of international best practice.”
“Before IMOS marine observing in Australia was agency by agency, and discontinuous. Now IMOS provides a mechanism for national design, implementation and leadership.”
“IMOS is the envy of many countries, especially as the NCRIS programs encourages collaboration,” says Dr Wijffels.
Over the last 20 years the game-changing robotic technology provided by the Argo float has revolutionized our ability to observe the global ocean to 2,000 metres deep. This incredible data set has been used in over 3000 papers internationally.
The sheer number of publications makes it difficult for Dr Wijffels to pick the most important scientific highlights from the Argo data.
After a moment though she starts off with, “discovering the climate drift signal that demonstrates the ocean is warming. I was surprised that it was detected so quickly, only after eight years of observations. Originally we thought it would take 15 years of data.”
“Another paper by Silvia Cole that looks at understanding the mixing of temperature and salinity. Another paper by Michele Ollitraut using Argo trajectory data contains beautifully detailed maps of the 1000m ocean circulation, including zonal jets, only made possible by the high-quality data and geographical coverage the Argo program provides.”
Lastly, she selects a paper by Jean-Baptiste Sallée that studied the exchange of heat and gases with the atmosphere in the Southern Ocean during winter.
“The Argo program made these observations possible for the first time ever. Prior to Argo there were very few winter surveys of the Southern Ocean as the research vessels would only go south during summer,” Dr Wijffels explains.
“The Argo data set made it possible to map the geography of these exchanges between the ocean and atmosphere, providing a profound new understanding of how the ocean and atmosphere interact.”
In looking forward to the next frontier for ocean observing Dr Wijffels recalls the conclusions of the last OceanObs conference in 2009.
“When the international community gathered at OceanObs we pledged to work together towards an integrated system. We recommended a framework for moving global sustained ocean observations forward in the next decade integrating new biogeochemical, ecosystem and physical observations while sustaining present observations.”
“We need to go deeper into the ocean and at the same time observe the coastal and offshore interactions.”
“In addition, we now realise we need to target the fast coupling between ocean and atmosphere. The global ocean observing systems needs to tackle this and Argo is only one part of the technology needed to observe this,” says Dr Wijffels.
Finally, Dr Wijffels points to the huge data sets accumulating from satellite observations.
“The next generation geostationary satellites are providing observations every 10 minutes. These huge data sets represent an amazing opportunity, but will be hard to use. Science users want products, which make the data easier to use and integrate with other data types.”
Dr Wijffels will leave Hobart in July to take up her new positon as a Senior scientist in physical oceanography at the Woods Hole Oceanographic Institution (WHOI). She will remain the international co-chair of the global Argo program, and part of the WHOI Argo team, so through this will remain in contact with IMOS.
“I am excited to reinvigorate and establish new collaborations in my new role at WHOI. I will be doing fundamental process science, looking at ocean-atmospheric coupling. There is also the opportunity to be involved in developmental engineering at WHOI, creating new platforms and sensors.”
IMOS Director Tim Moltmann recognises the outstanding leadership Dr Wijffels has provided not only for the IMOS Argo Facility but also in the IMOS Bluewater and Climate Science Node.