Graduate Students

photo of Dana McGuffin

Dana McGuffin

Airborne particles known as cloud condensation nuclei (CCN) enable cloud droplets to form as water condenses onto pre-existing CCN particles depending on the composition, concentration, and size of the aerosol. My interest is to investigate if mathematical tools developed in the areas of process control, optimization and machine learning can be adapted for aerosol and climate models with earth-based and satellite data to significantly improve predictions about aerosol behavior.

photo of Wayne Chuang

Wayne Chuang

My focus is on modeling the production of secondary organic aerosols (SOA) from chemical reactions in the atmosphere. SOA has been shown to have detrimental effects on human health; it also hasimplications on cloud formation and climate. Using the two-dimensional volatility basis set (2D-VBS), I model the reaction of biogenic emissions with oxidants (e.g. ozone and hydroxyl radicals) to understand how aerosols are formed and how they grow. We also simulate different atmospheric conditions, such as urban areas with high NOx concentrations, and examine how these conditions affect air quality and climate.

photo of Tom Brubaker

Tom Brubaker

My research focuses on the development of a new microfluidic method which can characterize the ice nucleation properties of microdroplets that contain a single particle directly sampled from an atmospheric aerosol. The new measurements enabled by this technique will address formation and evolution of clouds and their effects on radiative forcing.

photo of Sarah Rose Eilenberg

Sarah Rose Eilenberg

Approximately 3 billion people rely on traditional cookstoves burning solid fuels to cook their food. According to the World Health Organization, 4.3 million people die prematurely each year due to cookstove emissions. In addition, these emissions are significant contributors to climate change, and local and regional air quality. I am interested in studying the properties of cookstove emissions and potential improved cookstove technologies, to better represent them in climate and human health models.

photo of Meredith Schervish

Meredith Schervish

With the number and variety of different compounds in the atmosphere comes an incredible amount of different chemical reaction pathways for POA and SOA to take. We can model these compounds and their reactivity by describing them in terms of a volatility distribution. In the 2D Volatility Basis Set, the volatility of a species depends on the extent of functionalization and fractionation that it undergoes. It is important to understand this specific chemistry in order to effectively model the agingproducts of OA to compare to chamber experiments.

photo of Q.Y. Lu

Q.Y. Lu

Currently, I am interested in characterizing volatile organic compounds and particulate emissions from combustion sources, such as biomass burning and vehicle exhausts. And investigate their SOA formation potentials via field measurement and chamber experiments.

photo of Bob Peishi Gu

Bob Peishi Gu

Currently my work focuses on the spatial variation of VOCs in Pittsburgh. Statistical model and GIS tools have been used to investigate the source contribution to VOC concentrations and the health impacts to local residents. VOC data were collected through field measurements, both mobile and stationary sampling, from sites that scattered throughout the Allegheny County.

photo of Rishabh Urvesh Shah

Rishabh Urvesh Shah

My current project is to design an oxidative flow tube to simulate the atmospheric photo-oxidized formation of secondary organic aerosols from anthropogenic primary gaseous emissions. The flow tube will later be deployed in a mobile vehicle to study the spatial distribution of primary and potential aerosols in the greater Pittsburgh area.

photo of Leif Jahn

Leif Jahn

My current work focuses on analyzing the effects of chemical processing on the structure, composition, and ice nucleating properties or atmospheric aerosols. To this end, I utilize single-particle mass spectrometry as well as X-ray and electron spectroscopic techniques.

photo of Lydia Jahl

Lydia Jahl

My research focuses on secondary organic aerosol produced from isoprene, a major biogenic emission. Using an aerosol optical tweezers system and Raman spectroscopy, I can measure the heterogeneous kinetics of a single aerosol particle to study how the uptake kinetics of biogenic emissions vary with respect to particle composition. A better understanding of such systems can lead to a more complete understanding of particulate matter formation in the atmosphere.

photo of Adam Ahern

Adam Ahern

I'm investigating the chemical and physical characteristics of smoke from wood burning as it ages in the atmosphere. Smoke has a strong influence on climate change but how it ages is not well understood. I specialize in characterizing the addition (via coagulation and/or condensation) of organic material to the existing soot particles using a variety of mass spectrometry techniques. These include single particle mass spectrometry (electron impact and UV ionization) and ensemble aerosol mass spectrometry analysis of the particulate material, and proton transfer reaction mass spectrometry analysis of the gaseous material.

photo of Hassan Beydoun

Hassan Beydoun

I'm interested in understanding how aerosol particles such as mineral dust catalyze the freezing of supercooled cloud droplets. My work has focused on developing an optical tweezers to trap individual water droplets and collide them with particles to study the ice nucleating properties of various atmospheric aerosols.

photo of Kyle Gorkowski

Kyle Gorkowski

Atmospheric particulate pollution constantly changes as vapors (including water vapor) are condensed or evaporated as the composition and temperature of the air changes. The composition and size of these particles is very important for cardiovascular diseases and the earth's climate. To study how different types of particles interact with the surrounding vapor, I am developing an aerosol optical tweezers system. In this instrument a single particle is suspended indefinitely, which allows me to change the surrounding vapors to simulate and observe using Rama spectroscopy how the particles evolve in the atmosphere.

photo of Elina Karnezi

Elina Karnezi

In my research I initially used a TD model in order to constrain important organic aerosol properties such as volatility, enthalpy of vaporization and the mass accommodation coefficient. In my current work, I try to evaluate different parameterizations of the 2D-VBS in a Lagrangian Trajectory model with the latest measurements of OA collected in a major field campaign in Europe (PEGASOS) using among other tool airborne measurements by a Zeppelin! This state-of-the-art dataset will allow me to constrain further the different parameterizations and mechanisms of OA chemical aging.

photo of Zhongju

Zhongju (Hugh) Li

I am focusing on metal characterization of Pittsburgh with mobile sampling. Main topics include source apportionment of PM2.5 using PMF, spatial variation via GIS and redox activity assessment of PM.

photo of Marguerite Colasurdo Marks

Marguerite Colasurdo Marks

I use air quality models to investigate the effects of atmospheric particulate matter on global climate. Certain particles are very effective at serving as cloud condensation nuclei (CCN), and this "aerosol indirect effect" (particulate-induced changes in cloud properties) is the largest source of uncertainty in climate models. My research will utilize satellite and ground-level measurements to improve the representation of CCN in a global climate model and to understand natural sources of CCN.

photo of Michael Polen

Michael Polen

My research focuses on aqueous chemistry occurring in cloud droplets. This project will provide insights into the chemical reactions occurring in individual cloud droplets under realistic conditions through the use of an aerosol optical tweezers system. My second project is the use of a cold plate system to observe ice nucleation properties of biomass burning aerosols. Development of the system and use of the CMU smog chamber will provide further evidence of aerosol effects on cloud development, which can additionally be used to improve the representation of these poorly constrained processes in global climate models.

photo of Georges Saliba

Georges Saliba

Black carbon (soot) - emitted in the atmosphere during combustion processes - has potentially the second largest radiative forcing on the earth energy budget (second to CO2), with a large uncertainty associated with its forcing. I am interested in studying the optical and morphological changes that black carbon fractal aggregates incur when they are coated with condensing vapors from the atmosphere, in order to better constrain the forcing uncertainty associated with these particles.

photo of Antonios Tasoglou

Antonios Tasoglou

My research focuses on the formation and chemical characterization of biogenic secondary organic aerosol (beta-caryophyllene SOA) and anthropogenic secondary organic aerosol (toluene SOA) using a smog chamber and a suite of instruments. In the second step, I study the atmospheric mechanisms that chemically age the organic aerosol. Also, I investigate the chemical aging of the Biomass Burning Organic Aerosol (BBOA) and the optical properties of the Black Carbon particles from wood burning emissions.

photo of Ningxin Wang

Ningxin Wang

α-Pinene, a volatile organic compound emitted from pine trees, is a major biogenic source of secondary organic aerosols (SOA) in the atmosphere. My current study focuses on aging of α-pinene SOA under high NOx conditions. We simulate two stages of α-pinene oxidation processes in the Carnegie Mellon environmental chamber. Measurement techniques involve SMPS, HR-AMS, PTR-MS, etc.

photo of Qing Ye

Qing Ye

Broadly speaking, I am interested in any atmospheric chemistry and climate-related topics. Currently I am studying the interactions/transfer of organic mass between gas phase and particulate phase in the atmosphere by performing lab simulation smog chamber experiments and using a single-particle aerosol mass spectrometer. This is significant in understanding aerosols' chemical and physical properties and can help models better estimate aerosol's influences on our earth system.