Armin Sorooshian RDI Faculty Seed Grant: “Understanding why some particles shrink in the air upon humidification”

Dr. Armin Sorooshian was recently awarded a one year University of Arizona Research Discovery and Innovation Faculty Seed Grant to “Understand why some particles shrink in the air upon humidification”.

This project will allow Sorooshian to purchase a pre-humidification module for his Differential Aerosol Sizing and Hygroscopicity Spectrometer Probe (DASH-SP) instrument which can preemptively collapse particles prior to sampling polydisperse particles (ambient particles that have numerous sizes) at the inlet of the DASH-SP. Bypassing back and forth between this pre-humidification module will reveal as to whether the growth factor alternates between values above 1 (with pre-humidification) and below 1 (without pre-humidification). If this is the case, this would suggest that there is particle ‘re-structuring’ taking place as shown in Figure 1. Confirmation of re-structuring is critically important for numerous reasons in terms of how particles impact climate, health, and remote sensing data.

The significance of this work is that it can help unravel details associated with a phenomenon in aerosol science that is poorly understood and not treated by models or retrieval algorithms. Sorooshian’s past work has shown that this phenomenon is most prevalent with biomass burning plumes, and this research is expected to be of future importance as parts of the planet, especially the western United States, are anticipated to experience larger and more frequent fires owing to global warming and previously used fire-control strategies.