Puja Roy
-
Assistant Professor,
Atmospheric Sciences
- Cloud Physics, Microphysical Parameterizations, Numerical Modeling, Aerosol Cloud Radiation Interactions
Contact Info
- Email: puja.roy@UND.edu
Office Address
Atmospheric Sciences
Clifford Hall Room 400
4149 University Avenue Stop 9006
Grand Forks, ND 58202-9006
Biography
Dr. Puja Roy recently joined the Department of Atmospheric Sciences as an Assistant Professor in March 2026. Before joining UND, she was an Advanced Study Program Postdoctoral Fellow at NSF National Center for Atmospheric Research (NCAR), where she investigated cloud microphysical processes using a combination of theory, high-resolution numerical modeling, and observations. She earned her Ph.D. in Atmospheric Sciences from the University of Illinois Urbana-Champaign, where her doctoral research explored how evaporative cooling of supercooled droplets can influence ice formation at cloud edges. She has been extending this work through direct numerical simulation modeling, as well as conducting high-resolution large-eddy simulations of cloud systems using bin microphysics schemes in WRF and investigating raindrop breakup using the emerging Lagrangian Superdroplet Method for cloud microphysics. Her research ranges from native droplet physics to coupled cloud-system microphysical-dynamical interactions to better understand the impacts of complex cloud processes such as ice nucleation, entrainment and mixing, and raindrop breakup, to advance numerical weather prediction and artificial weather modification techniques.
Besides her love for watching and thinking about clouds, Dr. Roy is also passionate about teaching, science education and outreach, communication, science policy, and inclusive mentorship. She has served on the American Meteorological Society’s Board on Representation, Accessibility, Inclusion, and Diversity (BRAID) and as a mentor for the NSF SOARS program, and also chaired NCAR’s ASP Postdoctoral Seminar Series Committee. Her contributions to research, teaching, and service have been recognized over the years through multiple departmental and campus-level awards and NASA Group Achievement awards for the IMPACTS and CAMP2Ex field campaigns.
Outside of work, she enjoys reading, listening to music (especially discovering folk music from around the world), experimenting with different cuisines, traveling, and photography.
Upcoming:
Fall 2026 - ATSC 110: Meteorology I (Lecture)
Spring 2027 - ATSC 252: Applied Weather Modification
Cloud Physics - Warm-phase cloud processes, mixed-phase and cold processes such as supercooled droplet evaporation, ice nucleation and multiplication, microphysical parameterizations
Aerosol-Cloud-Radiation Interactions
Numerical Modeling
Ph.D. Atmospheric Sciences - University of Illinois, Urbana-Champaign (2023)
Dissertation: Investigation of Supercooled Cloud Droplet Temperatures and Lifetimes in Subsaturated Environments with Implications for Ice Nucleation at Cloud Boundaries
Advisors: Profs. Robert M. Rauber and Larry Di Girolamo
M.Sc. Physics - Indian Institute of Technology Bombay, Mumbai, India (2017)
B.Sc. Physics - Presidency University, Kolkata, India (2015)
Advanced Study Program (ASP) Postdoctoral Fellowship at NSF National Center for Atmospheric Research (NCAR) (Jan, 2024 - Jan, 2026)
- Graduate Teacher Certificate, University of Illinois, Urbana-Champaign (UIUC) (2023)
- Graduate Mentor Certificate, University of Illinois, Urbana-Champaign (2021)
- Ogura Operational and Applied Meteorological Paper Award, UIUC (2025)
- NASA Group Achievement Award for IMPACTS (2024)
- NSF NCAR Advanced Study Program (ASP) Postdoctoral Fellowship (2023)
- Graduate Student Diversity, Equity, and Inclusion Award, ATMOS, UIUC (2023)
- Dr. Ruth Nicole Brown Coalition Award, Women’s Resources Center, UIUC (2023)
- NSF Student Award Recipient for AMS Summer Policy Colloquium, Washington, DC (2022)
- NASA Group Achievement Award for CAMP2Ex (2021)
- Ogura Outstanding Teaching Assistant Award, ATMOS, UIUC (2020)
- Teachers ranked as Excellent by their students, UIUC (2020, 2019)
- Advanced Study Program (ASP) Summer Colloquium, NCAR, Boulder, USA (2018)
- Summer Research Fellowship, Physical Research Laboratory (PRL), India (2016)
- Indian Academy of Sciences (IAS) Summer Research Fellowship (2015)
- Undergraduate Research Associate, Saha Institute of Nuclear Physics (2014)
- Jagadis Bose National Science Talent Search (JBNSTS) Scholarship (2012)
- INSPIRE Scholarship, Dept. of Science and Technology, Govt. Of India (2012)
- Top 1% ISC Board, Council for Indian School Certificate Examinations (2012)
- National Talent Search Examination (NTSE) Scholarship, Govt. Of India (2008)
Publications:
Roy, P., Rauber, R. M., and Di Girolamo, L., “Evolution of cloud droplet temperature and lifetime in spatiotemporally varying subsaturated environments with implications for ice nucleation at cloud edges”, Atmospheric Chemistry and Physics 24(20) (2024): 11653-11678. [Link]
Roy, P., Rauber, R.M., and Di Girolamo, L., “A closer look at the evolution of supercooled cloud droplet temperature and lifetime in different environmental conditions with implications for ice nucleation in the evaporating regions of clouds”, Journal of Atmospheric Sciences 80(10) (2023): 2481-2501. [Link]
Di Girolamo, L., ..., Roy, P., Nesbitt, S., Rauber, R.M., and the CAMP2Ex Science Team, “Data fusion visualization for NASA CAMP2Ex field campaign”. [Link]
Manuscripts in prep.:
Roy, P., Chandrakar, K., Morrison, H., Xue, L., Tessendorf, S., “Investigation of collision-induced raindrop breakup on evolution of droplet size distributions using Lagrangian superdroplet method in idealized box model simulations.”
Roy, P., Tang, W., Rauber, R.M., Riemer, N., Di Girolamo, L., “Investigating immersion freezing capabilities of different aerosol species within evaporating supercooled cloud droplets employing a particle-resolved model.”
Presentations:
[14] Roy, P., Chandrakar, K., Morrison, H., Xue, L., Tessendorf, S., “Impacts of Collision-induced Drop Breakup on Droplet Size Distributions using Lagrangian Superdroplet Method in Idealized Box Model Simulations”, American Meteorological Society (AMS), Houston, TX, January 2026. [Poster]
[13] Roy, P., Rauber, R.M., Di Girolamo, L., Chen, S., Xue, L., Tessendorf, S., ”Can Evaporative Cooling of Water Droplets Play a Role in Enhancing Ice Formation at Moderately Supercooled Cloud Boundaries?”, EGU General Assembly Meeting, Vienna, Austria, April, 2025. [Virtual Talk]
[12] Roy, P., Chandrakar, K., Morrison, H., Xue, L., Tessendorf, S., Grabowski, W.W., “Impacts of Collision-induced Drop Breakup on Droplet Size Distributions using Lagrangian Superdroplet Method in Idealized Box Model Simulations”, American Meteorological Society (AMS), New Orleans, LA, January 2025. [Talk]
[11] Roy, P., Rauber, R.M., Di Girolamo, L., Chen, S., Xue, L., Tessendorf, S., “Impacts of Evaporative Cooling on Droplet Temperature and Radius Evolution at Moderately Supercooled Mixed-phase Cloud Boundaries”, American Meteorological Society (AMS), New Orleans, LA, January 2025. [Poster]
[10] Roy, P., Chandrakar, K., Morrison, H., Xue, L., Tessendorf, S., Grabowski, W.W., “Impacts of Collision-induced Drop Breakup on Droplet Size Distributions”, US CLIVAR Micro2Macro Workshop, Laramie, WY, October 2024. [Poster]
[9] Roy, P., Rauber, R.M., Di Girolamo, L., “Supercooled Evaporating Cloud Droplets and Ice Nucleation at Cloud Edges”, Aggregates Workshop, NSF NCAR, Boulder, CO, August 2024. [Talk]
[8] Roy, P., Chandrakar, K., Morrison, H., Xue, L., Tessendorf, S., Grabowski, W.W., “Impacts of Collision-induced Drop Breakup on Droplet Size Distributions using Lagrangian Superdroplet Method in Idealized Box Model Simulations”, International Conference on Clouds and Precipitation (ICCP), Jeju Island, South Korea, July 2024. [Poster]
[7] Roy, P., Rauber, R.M., Di Girolamo, L., “Evolution of Cloud Droplet Temperature and Radius in Spatiotemporally Varying Subsaturated Environments with Implications for Ice Nucleation at Cloud Edges”, International Conference on Clouds and Precipitation (ICCP), Jeju Island, South Korea, July 2024. [Talk]
[6] Roy, P., Rauber, R.M., Di Girolamo, L., “Evolution of Cloud Droplet Temperature and Radius in Spatiotemporally Varying Subsaturated Environments with Implications for Ice Nucleation at Cloud Edges”, American Meteorological Society (AMS), Baltimore, MD, January 2024. [Poster]
[5] Roy, P., Rauber, R.M., Di Girolamo, L., “Evolution of Cloud Droplet Temperature and its Implications for Ice Nucleation in Cloud Top Generating Cells”, SNOWIE Science Team Meeting, Boulder, CO, May 2023. [Talk]
[4] Roy, P., Rauber, R.M., Di Girolamo, L., “Numerical Simulations of Cloud Droplet Temperatures in Sub-saturated Environments”, AGU, Chicago, IL, December 2022. [Poster]
[3] Roy, P., Rauber, R.M., Di Girolamo, L., “Simulations of Spatiotemporally Varying Cloud Droplet Temperatures for Droplets Introduced to Sub-Saturated Environments”, AMS Collective Meeting, Madison, WI, August 2022. [Talk]
[2] Roy, P., Rauber, R.M., Di Girolamo, L., “How do different environmental conditions and droplet characteristics impact the evolution of cloud droplet temperature?”, Annual Geophysical Union (AGU) Annual Meeting, New Orleans, LA, December 2021. [Poster]
[1] Roy, P., Rauber, R.M., Di Girolamo, L., “How do different environmental conditions and droplet characteristics impact the evolution of cloud droplet temperature?”, International Conference on Clouds and Precipitation, Virtual conference, IITM-Pune, India, August 2021. [iPoster]