April 1, 2020 | Published by |

We would like to open this report during this difficult time with some good news. Our own Sopia Lestari has been selected as a recipient of the Australia Awards Hadi Soesastro Prize for 2020. The Prize is intended to supplement the academic programs of current recipients of Australia Awards from Indonesia (including Endeavour Scholarships) undertaking PhD studies in the areas of Political Economy, International Economic Relations, or an area of study that is a priority for Australia-Indonesia development cooperation. It’s an impressive result for Sopia as only two Hadi Soesastro Prizes are awarded annually.

Further congratulations should also go to CLEX Chief Investigator Lisa Alexander who has had a rewarding few months. First she was announced as a new AMOS Fellow along with CSIRO’s  Rachel Law and now has been promoted to full professor.

Meanwhile, the important role that CLEX researchers play in Australia’s climate science community was also highlighted by the publication of the Climate Processes Research in Australia Report led by RP1’s Christian Jakob. The report was produced in response to a request by the National Climate Science Advisory Committee (NCSAC) for input to its strategic discussions in the area of climate processes research. Specifically, it summarises the current state of climate processes research in Australia, identifies gaps, and provides options for moving the area forward into the next decade. You can find a link to the full report here. It will be a key document that will inform the infrastructure and direction of Australian climate research into the future. 

Similarly, the current research coming out of the program is setting the foundations for future research as we aim to tackle some of the grand research challenges posed by the science of extreme rainfall. A significant portion of this research over the past three months has focused on observations.

One of the key challenges around observations in general and extreme rainfall, in particular, revolves around data sharing between countries. Extremes-relevant data is often restricted because of concerns around the sovereignty of data and commercialisation. As a result, raw data is replaced by ‘indices’ derived from daily and sub-daily data that measure aspects of extreme precipitation frequency, duration and intensity because these have far fewer data exchange issues. Recent research by the Extreme Rainfall team examined the advantages and pitfalls of using these indices. It concluded that satellite precipitation products could be used to supplement existing data that uses longer-term in situ measurements. However, more research is required to understand the limitations of the satellite-based estimation process and the challenges of scale between these and in situ measurements.

In follow-up research, CLEX researchers began to look at these issues more closely. The researchers took 22 precipitation data products and divided them into four categories to evaluate the spread of measurements and determine observational uncertainty. They concluded that none of the datasets by themselves produced a best estimate for precipitation extremes. They suggested the path to getting the most accurate assessment was to avoid using reanalyses as observational evidence and to consider in situ and satellite data (the corrected version preferably) in an ensemble of products. This approach produced a better estimation of precipitation extremes and more plausible observational uncertainties.

Another observational study revealed some fascinating interactions between clouds and their environment. The study investigated vertical profiles of horizontal wind speed measured by instruments on ascending balloons near Darwin, Australia. This vertical movement influences fair weather and cloudiness and it has, until recently, been considered that clouds responded to the vertical movement but had no effect on it. However, the Darwin observations confirmed a recent study of the Atlantic Ocean that showed the clouds themselves can emit waves in a way that is similar to stones being dropped in a pond and this, in turn, influences vertical motion. These findings suggest a two‐way coupling of clouds to their environment with potentially important consequences for our understanding of weather and climate phenomena.

Some important modelling work has also been carried out by researchers from the Extreme Rainfall program. They examined Australia’s new, high-resolution version of the ACCESS climate model to determine its ability to simulate tropical cyclone climatology. The initial results showed good simulations and this allowed the researchers to proceed to a second study that looked at how cyclones form around Australia. The results of this work showed the importance of atmospheric stability and vertical wind changes in the formation of these cyclones.

We also welcomed a new researcher/student to our ranks. Flora Norton who has been doing an Undergraduate Scholarship program with Yi Huang, is now officially affiliated with CLEX as a University of Melbourne Masters student.  Flora will be working on Measuring the world’s cleanest air – validating the measurements above the Southern Ocean with Robyn Schofield. 

Beyond our research members of the Extreme Rainfall can also a list a number of noteworthy achievements. PhD student Kim Reid, along with colleagues from Earth Sciences was on the committee that successfully ran the 32nd Victorian Universities Earth and Environmental Science Student Conference. Kim’s outreach activities have also included a regular blog on the CLEX website that has tackled some topics that are important to students and young researchers. Her latest post, How to have a successful conference when you’re an introverted agoraphobic, was particularly well-received, dealing with mental health issues in an accessible and very practical manner.

In terms of reaching new public audiences, Andrew King made quite an impact when one of his tweets that showed the three hottest days on record in Australia was retweeted by Greta Thunberg. The result: 1.46m impressions, 4324 retweets, and an additional few hundred followers. Finally, we were visited by Wojtek Grabowski at our University of Melbourne node during December. While here, Wojtek presented seminars at Monash, CSIRO, and BoM. We are also hosting Dr Hugh Morrison from NCAR at UNSW – he’s given seminars at UNSW, Melbourne, Monash, and BoM.