Darko Koracin

Scientist tracks ozone and particulate matter in the Tahoe Basin’s atmosphere

After a series of California air quality violations, Lake Tahoe researchers are shifting their attention to air quality problems in the basin. Desert Research Institute (DRI) research professor Darko Koracin is applying his expertise in advanced air quality modeling for complex terrain to unravel the complex air quality issues in one of the country’s most pristine environments.

Though the states of California and Nevada continually work together to solve Lake Tahoe’s environmental concerns, the fact that the basin straddles the Californian border often complicates these issues. The amount of ozone in the Tahoe Basin violated California’s air quality standards several times between 2006 and 2010. California’s air standards rank as one of the strictest in the country. Still, the violations exposed the lack of research and management being done on the Tahoe Basin’s air quality.

To address the issue, Koracin and his research partners started an air quality modeling project this year, using RI’s HPC (high performance computing) data center and expert integrated computer systems for modeling extremely large datasets, to track the amount of ozone and particulate matter in the Tahoe Basin.

Koracin said ozone is what’s called a secondary pollutant, meaning other pollutants must interact to create it. The Environmental Protection Agency tracks ozone closely, as it can be detrimental to plants and harmful to humans.

“The most dominant sources are vehicle emissions, which are not easy to control,” Koracin said. “Some chemicals also don’t directly make ozone but are important to the ozone cycle.”

Although local sources like cars contribute to the amount of ozone in the basin, wind can also transport it from distant locations. This added complication makes ozone difficult to address locally. In order to create accurate models, Koracin will have to determine how much of the ozone comes from industrial sources in California and its Central Valley.

Particulate matter can also be harmful to the water and affect visibility in the basin. Particulate matter comes from the fumes and smoke created by cars, boats and fires. Though the current project will only focus on the warmer months of the year; Koracin said the next step is to model the air’s particulate matter content during the winter. Residents using wood-burning stoves in the colder months may add a significant amount of particulate matter in the air.

“For the ozone part of the study, there is a good correlation with high temperatures,” Koracin said. “But particulate matter is often a winter problem.”

Koracin, who has more than 20 years of experience investigating weather and climate phenomena and creating atmospheric pollutant models at DRI, is well suited for the challenge of maintaining air quality standards in the Tahoe Basin.

In addition to his research, Koracin also teaches and mentors students. He divides his time in the lab, teaching at the University of Nevada, Reno and lecturing about air quality at other colleges, including his alma mater, the University of Croatia, Zagreb.

The air quality project is one of his first projects at Lake Tahoe, but Koracin had always recognized the need for more research there.

“Lake Tahoe is one of the most beautiful areas in the U.S.,” he said. “There’s a big concern about the trends in air quality from the residents and tourist agencies to the federal and local agencies. A lot of work is being done and will continue to be done to preserve its pristine properties and air and water quality.”