I am honored to receive the Doctoral Finishing Fellowship at Michigan Technological University. I’m grateful to the Graduate School and the Graduate Dean Awards Advisory Panel for this support, and especially to my advisor, Prof. Raymond Shaw, whose unwavering guidance and support throughout my PhD have been invaluable in shaping both my research and my growth as a scientist. Before joining MTU, I completed an M.S. at the University of Tehran, Iran. At MTU, I have pursued Ph.D. research in atmospheric physics examining how tiny airborne particles tip the balance between haze and cloud.
First, we showed that not only “too many particles” but also “too large particles” can prevent cloud formation and leave the system in haze. In controlled chamber experiments, we held conditions fixed and varied particle size: larger salt particles drew water rapidly yet required extra time to become true droplets, draining the limited water supply and slowing activation. We derived a simple scaling showing that activation time rises sharply with particle size.
Second, we introduced a practical method to diagnose the haze–cloud state without direct supersaturation measurements by tracking how haze-droplet and cloud-droplet counts co-vary. In both chamber experiments and large-eddy simulations, this relationship flips sign across three regimes—near zero in clean conditions, positive in moderate conditions, and negative in polluted conditions—providing an easy way to tag regimes in real fogs and low clouds and to guide interventions (e.g., fog dispersal or seeding) toward situations where they are more likely to work.
I also thank my committee members, the Cloud Chamber group, and the faculty and staff of the Department of Physics for their support throughout my Ph.D. journey.