IU’s Big Red II plays big role in climate-change research

Once professor and graduate student at IU, Sara Pryor and Paola Crippa go back to their roots as they use big data to help gauge aerosols’ impact on the environment

According to a 2014 World Health Organization report, 7 million people die each year as a result of exposure to pollution.

One issue the vast majority of people can agree on is that climate change is extremely serious. But rather than simply pontificating about how to combat the issue, Sara Pryor and Paola Crippa, two atmospheric researchers with strong ties to Indiana University, are working to solve it.

While the duo now works elsewhere—Pryor at Cornell University, Crippa at Newcastle University in the United Kingdom—they continue to rely upon IU’s Big Red II supercomputer in their attempt to use big data to alleviate one of society’s grand challenges: climate change.

Sara Pryor and Paola Crippa

Sara Pryor (left) once taught Paola Crippa (right) at IU Bloomington. Now, they work together in an effort to alleviate climate change.

"Some universities limit access to high performance computing (HPC), claiming it is expensive to support. IU’s success in acquiring massive new grants and making real scientific and technological breakthroughs via use of high performance computing makes it clear that their investment in HPC is paying huge dividends not only for science, but for society," said Pryor. "Our work—seeking to improve understanding of aerosol populations and better model them—is a critical first step in developing policies to reduce the climate impact and human health toll from high aerosol concentrations."

Aerosols, formed when air pollutants (which have seen an increase due to technological advancements in the industrial and agricultural fields, among others) are transformed in the atmosphere by chemical reactions, change the Earth’s climate by interacting with sun rays and clouds, and are also harmful to the health of the planet’s inhabitants.

Backed by grants from the NSF and, most recently, NASA, Pryor and Crippa hope their research can eventually help reverse sobering statistics such as a 2014 World Health Organization report stating that 7 million people worldwide and one in eight deaths globally occurred as a result of exposure to pollution. Through their work with IU’s Research Technologies, the pair have used Big Red II, IU’s main system for high performance parallel computing, and the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) to make millions of individual computations in warp speed and create sophisticated long-term simulations, resulting in more useful climate projections.

"In our research, we investigate processes responsible for particle formation and growth in the atmosphere by using state-of-the-art model simulations of meteorological and chemical conditions over eastern North America," said Crippa. "By comparison with satellite observations, we are able to assess model performance in describing spatio-temporal variability of particle properties, a feature essential to more accurately quantify their current and future impact on Earth’s climate and human health."

The genesis of the professional partnership between Crippa—who received her Ph.D. from IU in 2013 and has gone on to be awarded with the L'Oréal-UNESCO for Women in Science Fellowship—and Pryor, formerly IU’s associate vice provost for faculty and academic affairs, took shape when Crippa was an atmospheric science doctoral student of Pryor’s at IU Bloomington.

"We have really complementary skills and research interests," said Pryor. "My obligation to continue to mentor my graduate students continues long after they graduate."

Their shared background at the university was integral to their initial research, as it began as an unfunded project before proof-of-principle work allowed them to compete for federal awards, meaning free access to IU’s resources was essential to getting things off the ground.

"This is critically scientific work that will help inform our understanding of the world’s climate and how it’s changing," said Craig Stewart, IU associate dean, Research Technologies, and executive director, Pervasive Technology Institute. "It represents a wonderful continuation of the partnership that we began with Sara and Paola while they were at Indiana University."

The researchers also credit the staff at IU’s Pervasive Technology Institute and the powerful abilities of Big Red II for helping them continue to make remarkable progress.

"The technical support from Abhinav Thota [of the Scientific Applications and Performance Tuning group within IU Research Technologies] and the resources offered by the High Performance Computing group at IU enabled us to use for the first time a state-of-the art regional model including descriptions of atmospheric physics, dynamics, chemistry, and aerosols at very high resolution, which only a few research groups worldwide have the training to run and nobody has ever run systematically on a Cray machine," said Crippa. "So we are exploiting the most advanced computational resources to perform unique simulations for climate applications." 

Pryor added, "We are conducting massive numerical experiments—millions of individual computations. We can only do that on massively powerful computers! We also use a massive amount of satellite observations to evaluate our simulations. NASA generates over 6 TB of earth observing data per day, so that’s a lot of data to store and analyze when you think our simulations are currently for a whole calendar year.

"The investment IU is making in providing state-of-the-art computational facilities for the analysis of these 'big data' makes IU a leader in applied computational science and is advancing science and technology across a vast array of fields, not only our own," she continued. "We can do our year-long simulations in just 10 days, even using just a tiny fraction of Big Red II’s power."

Just think—if such heady work one day helps effect a positive change in environmental policy, a unique bond that began in an IU Bloomington classroom would have played a small part in the effort.