Dr. Zhang studies the effects of airborne particulate matters (PM) and gaseous pollutants on air quality, climate change and ecosystem, using numerical models and experimental techniques. One particular area he is working on is environmental nanoparticles. Nanoparticle pollution affects public health by depositing deeper in our lungs and moving into the blood circulation. These nanoparticles can also grow into cloud condensation nuclei (CCN). Changes in CCN concentration may affect cloud reflectivity and lifetime, thus perturbing the energy balance of the planet. His research in this area focuses on characterizing various emission sources and their transformation in the atmosphere, especially the rapid changes in the first few minutes after emission. One important goal is to establish a source-to-receptor relationship for airborne nanoparticles. The "receptor" refers to either humans or the climate system. Another goal in this area is to improve laboratory engine measurements to represent "real-world" emissions, and to develop optimal control strategies to mitigate human exposures to traffic-generated air pollution. In addition, Dr. Zhang is working on modeling urban, regional and global aerosols. His research in this area focuses on improving physical representation and computational efficiency of aerosol module in regional and global models. An important application of his research is to investigate the atmospheric deposition of nitrogen and Mercury into the ecosystem.

Dr. Zhang joined the Cornell MAE faculty in 2006. Previous to that, he was a research scientist at the Air Quality Research Center, University of California at Davis. He was a visiting scientist to USEPA National Exposure Research Laboratory in 2000 and 2002.