19 June 2015

Researchers around the world aim to achieve a first author publication in Nature, but few succeed. So, it was no small feat when PhD student Jackson Tan at the ARC Centre of Excellence for Climate System Science succeeded with his paper, Increases in tropical rainfall driven by changes in frequency of organized convection.

Jackson has since moved on to work with NASA but credits the incredible advantages of working in an ARC Centre of Excellence both with his PhD success and the doors it has opened for his future career.

Jackson took some time out of his day to talk about his Nature paper, the crucial role of the ARC Centre of Excellence in his career and where he goes to from here.

What prompted you to do a PhD with the ARC Centre of Excellence for Climate System Science?

Before I started, I was doing my Masters in Earth Sciences at the ANU. I did a short project in oceanography, co-supervised by Dr Andy Hogg who is now part of the Centre. When I informed him of my intention to pursue a PhD in atmospheric science, he strongly recommended me to consider Monash University or the The University of Melbourne. These two universities have a stronger focus on atmospheric science. As the Centre was starting up very soon, there would be immense opportunities for me as a PhD student, both academically and professionally.

Furthermore, when I started contacting potential PhD supervisors, Prof Christian Jakob gave me a sales pitch, describing the advantages of working with the Centre. The close connections and the potential opportunities for interactions between various universities was particularly seductive.

Very early in your PhD, your supervisor, Professor Christian Jakob, sent you off to the Maldives to observe the Madden-Julian Oscillation (MJO). How did this help and inform your subsequent PhD work, the paper and potentially your future career?

My PhD work is largely data analysis based on satellite measurements. This anchors me in front of a computer most of the time. My participation in the DYNAMO (Dynamics of the Madden-Julian Oscillation) field campaign was hugely educational. It made me understand the great challenges of measuring the atmosphere, the difficulties of obtaining quality data, and the degree of coordination needed to execute such an intricate campaign. Above all, it made me appreciate the immeasureable efforts that formed the starting point of my work.

While my experience did not have a direct influence on the paper, it certainly helped prepare me for my career. My current work compares satellite products with ground-based measurements to improve the quality of global precipitation estimation and thus advance our understanding of rainfall processes that will lead to more accurate predictions. This has benefited from the perspective I gained during my three weeks in the Maldives.

And of course, one of the chief advantages of such field campaigns was that I got to meet researchers from around the world, many of whom existed previously in my mind as authors of notable papers and standard textbooks. These connections remain with me and will undoubtedly aid me in my future.

Was there any stage during your PhD where you started to recognise that you had a paper good enough to be accepted by Nature?

Not on my own. It was only about halfway through my PhD that Christian raised the possibility that some of my results may stand a chance for publication in Nature. Even then, it was a remote possibility, and these results were bounced around many times between us and went through numerous iterations before it shaped into something viable for submission to Nature.

What was your response when you found out Nature had accepted your paper?

To be honest, just pleasantly pleased, no more than any other papers of mine getting accepted! (Perhaps less than my first paper, because first papers are always special!).

In truth, I knew we had constructed a very strong paper, very much due to the contributions of my co-authors. From the first round of peer review, it was clear that our paper possessed a very good chance of publication. Therefore, it was not a surprise when we finally got through to the end.

What were the most enjoyable and challenging parts of your PhD at the ARC Centre of Excellence for Climate System Science?

It is hard to single out an event that marks the best or worst times of my PhD.

The joys of my PhD came from the moments when I cracked a particularly difficult puzzle, obtained a result that was meaningful, or had an insight that gave me a rush of euphoria. That is what keeps me motivated every day, because I will never know what I may find out today.

Difficult periods of my PhD occurred when results I thought were significant turned out not to be so, especially results that took me weeks or even months to get.

I recall one incident in which I presented some new results to Christian, and he said, "You cannot say this because..." and he gave a few excellent reasons. That did deflate me quite a bit for about a week or so, and I thought really hard about it. He was right, of course, but I realised that my results could be interpreted in another way. When I presented to him the results again, and he started, "But you cannot do this...", and I said, "Yes I know, but now I am turning this around and interpreting it this way...". And he went, "Ahhh!...". That was a moment I relished!

Do you think working in an ARC  Centre of Excellence helps with research?

To answer this objectively, I would need to at least redo my PhD without the Centre, something that I will resist with all my effort!

However, I can identify numerous advantages that being in the Centre gave me. The greatest advantage, in my opinion, is the interactions with researchers from other universities. This includes the invaluable meetings with other researchers but also the fruitful discussions amongst early-career researchers. I have shown most of my results, including the study that made it into Nature, to others in the Centre and received very useful feedback in turn. While such interactions are possible without the Centre, what the Centre does is to facilitate, support and encourage such communications. Networking is arguably one of the more overlooked aspect of a research career by an early-career researcher; the Centre helps by providing ample opportunities for networking.

In addition, the Centre runs different courses tailored for climate science researchers. Unlike many generic courses in a university or faculty, these courses are much more relevant to us in this field. In particular, the scientific writing course is singularly the most useful course that I have ever attended. These professional development courses that the Centre organises are highly beneficial to researchers.

Furthermore, it would have been unlikely for me to land a postdoc position with NASA without the Centre. My current research compares satellite-based rainfall measurements with ground-based Australian radars. The assistance I received from the Centre of Australian Weather and Climate Research was instrumental in the success of my proposal, and the ARC Centre of Excellence for Climate System Science plays a key role in strengthening the connections between these different institutions.

The Centre certainly helped me in many ways, as a PhD student, as a postdoc, as a researcher.

A Centre Chief Investigator, Professor Christian Jakob, was your supervisor. How did he help you during your PhD and what was it like to be supervised by him?

Christian is a great supervisor in that he knew the trajectory of a PhD student throughout his/her candidature and would modify his supervision style in accordance. At the beginning, he would be at the helm of my research, instructing me the tasks I needed to do. As my candidature progressed, he would gradually let me take control, but constantly providing me with insights on the larger picture into which my results fitted. Even with his busy schedule, he would spend one hour a week discussing my results instead of saving the world from climate change.

To be perfectly frank, it was a bit intimidating to be supervised by him. This is not because of his personality, but because of the staggering ease in which he is able to identify the significance of a result and fit it within our understanding. During my PhD and even now, whenever I encounter a problem or a result, I would ask myself, "What would Christian do?" In the end, I am incredibly fortunate to be surrounded by people like him in the Centre and at Monash, from whom I could learn so much.

What are your memories and thoughts about your time at the ARC Centre of Excellence?

I remember, particularly when it was on display during the annual workshops, the staggering breadth and depth of research going on in the Centre. I remember the diversity of ideas and opinions that drives the intellectual force behind our work. I remember the willingness of everyone to help each other, be it the discussion of a result or feedback on a particular approach.

You have now moved on to NASA. Describe the new position and what you have been doing there.

My current research centres upon the Global Precipitation Measurement (GPM) mission. The GPM Core Observatory satellite, launched February 2014, serves as a standard to which measurements from a constellation of satellites are calibrated and unified into high-resolution precipitation products.

My work focuses on the validation of these products using Australian radars from the surface, including on the new RV Investigator, which is the first-ever surface rainfall radar in the Southern Ocean. This will allow us to make refined precipitation products, especially over the Southern Ocean where measurements are sparse and over the Maritime Continent where accurate predictions remain challenging.

Building upon our knowledge of these improvements, I will characterise precipitation properties and advance our understanding of associated processes, ultimately allowing us to produce reliable rainfall projections.

How does NASA and your post-doc work differ?

Instead of being an end-user to satellite-based rainfall products (on which my Nature study is based), I am now involved in the production of these products that so many researchers use. But I still sit behind a computer most of the time!

Where to from here for your career?

Well, first of all I need to complete my postdoc stint here. Thereafter, it is hard to say. My personal philosophy is not to set a specific goal, such as to reach a particular position in academia, because it is highly inflexible and vulnerable to factors beyond my control. Instead, my philosophy is this: I do not know where I will go, but merely that I should keep going up at every opportunity.

Perhaps too often I look at myself and do not think I am intelligent enough for the tasks ahead. And in these moments I would approach the issue as a scientist. Null hypothesis: I am not clever enough; my aim: work hard to reject the null hypothesis. And if I were to finally hit the ceiling of my abilities—that I can no longer reject the null hypothesis—then I will comfortably know my intellectual limits and organise my career accordingly. If I cannot move up, I can move sideways!

This article was prepared for ARChway by the ARC Centre of Excellence for Climate System Science.



Image: PhD student Jackson Tan.
Image courtesy: NASA. Photo by Patrick Black, Wallops Flight Facility.