UNIVERSITY PARK, Pa. — Penn State researchers spent their summer in one of the world’s wettest regions as part of an international effort to study extreme rainfall, hazardous weather events that can trigger deadly and damaging events like flooding and landslides.
The researchers are participating in the Prediction of Rainfall Extremes Campaign in the Pacific (PRECIP), a $6 million field campaign in Taiwan and Japan funded by the National Science Foundation to improve our understanding of the processes that produce extreme precipitation.
“Our goal is to get a better understanding of what the underlying factors are for the events that create the most extreme precipitation,” said Anthony Didlake, associate professor of meteorology at Penn State and an investigator on the project. “We want to study extreme precipitation events that span the spectrum of short-duration heavy rain to long-duration light rain.”
PRECIP scientists aim to identify key physical processes and environmental variables for these events and to improve models for forecasters predicting severe rainstorms around the world.
“The knowledge we acquire during and after this field campaign will be beneficial for both our understanding and forecast capability of extreme rainfall events worldwide,” said Yunji Zhang, assistant professor of meteorology and assistant director of the Penn State Center for Advanced Assimilation and Predictability Techniques.
Taiwan and Yonaguni, the westernmost island in Japan, represent an ideal laboratory, the scientists said, because the region has consistently high humidity, an important ingredient for heavy rain producing storms. This allows them to focus on subsequent processes and interactions that take place during severe weather events.
“In order for us to better pin down what is most important, we had to find a location where one of the necessary ingredients — moisture — is consistent,” Didlake said. “So we can focus more on other factors like the winds, the thermodynamics, and the topography. This region of abundant moisture also has a confluence of different types of extreme weather events — afternoon thunderstorms, Meiyu frontal rainfall and typhoons, or tropical cyclones.”
Penn State researchers are collaborating with scientists from seven other U.S. universities and the National Center for Atmospheric Research, and scientists from universities and institutes in Taiwan, Japan and Korea. Professors Michael Bell and Kristen Rasmussen at Colorado State University lead the project.
The scientists began collecting data in late May and will continue through early August. The campaign involves a large suite of ground- and air-based technologies that will provide views of the inner details of storms and precipitation and take measurements of moisture, temperature, wind and raindrops.
Didlake and Penn State students Cameron Chuss and Jordan Rendon, who traveled to Taiwan in June and July for three weeks, are part of the science team studying these observations and processing the data to pinpoint storm characteristics important for creating extreme precipitation events.
Zhang is part of the modeling team, who is using computer weather models to provide real-time forecasts to the field team. The modelers are using data assimilation techniques developed by Penn Sate scientists. After the field campaign, scientists will evaluate the forecasts and compare them with the observations, offering new insights into the strengths and weaknesses of the models, the scientists said.
“We still lack adequate answers of why some extreme rainfall events can be accurately predicted several days ahead while sometimes — more often — forecast uncertainties pose great forecast challenges, and what distinguishes these two types,” Zhang said. “This field campaign will not be able to solve all these issues, but it can expand our current understanding and capability and lead to many future explorations of extreme rainfall.”
Visit our sponsors
Wise (formerly TransferWise) is the cheaper, easier way to send money abroad. It helps people move money quickly and easily between bank accounts in different countries. Convert 60+ currencies with ridiculously low fees - on average 7x cheaper than a bank. No hidden fees, no markup on the exchange rate, ever.