Clarkson Graduate Student Advances Stratospheric Research, Earns National Presentation Award
Clarkson University graduate student from the department of Mechanical and Aerospace Engineering, Nagarajan Radhakrishnan is helping scientists better understand how tiny particles high in the atmosphere influence Earth’s climate through his work developing a new device for sampling aerosols in the stratosphere.
Radhakrishnan recently presented this research at the 2025 American Association for Aerosol Research (AAAR) Conference, where his talk was selected for the Best Oral Presentation Award. His award-winning work centers on the Nested Inlet for Stratospheric Sampling of Aerosol (NISSA), a tool designed to collect particle samples at altitudes above 60,000 feet. The inlet, flown this spring on NASA’s WB-57 research aircraft, was designed such that the intense turbulence that can form in the inlet when operated at high flight speeds in minimized. That turbulence often disrupts particle measurements, making accurate sampling a long-standing challenge.
Particles in the stratosphere play a major role in Earth’s radiation budget — the balance between sunlight reflected back into space and heat absorbed by the atmosphere. The combination of particle size and composition determines the strength of this effect. Earlier Clarkson research showed that particles just 10 times larger than average can reflect 100 to 1,000 times more light, giving them a powerful influence on the planet’s temperature.
To address the need for reliable, in-flight data, Radhakrishnan and his team designed NISSA to limit turbulence and improve measurement accuracy. They also collected rare turbulence data from inside the inlet while operating in the stratosphere, creating a valuable dataset for optimizing future samplers for climate and atmospheric studies.
By improving how scientists measure large particles in the upper atmosphere, this research may lead to more accurate climate models and better predictions of how natural events — such as volcanic eruptions — might temporarily cool the planet.
