The stratospheric ozone layer is critical to our planet and the health of the planet's population. The chemical reactions influencing ozone in the stratosphere are difficult to study because the stratosphere is difficult to reach. Our work presents new in situ observations of dinitrogen pentoxide (N2O5), a critical molecule that influences stratospheric ozone. These first-time observations stem from the NOAA Stratospheric Aerosol Processes, Budget, and Radiative Effects (SABRE) campaign. In combination with simultaneous observations, new data on N2O5 greatly improve our understanding of key gas/particle reactions that alter ozone. Our results show striking variability in the reaction rate — previously considered to be a constant value. The rate varies by factors of up to 100x. The results show that different stratospheric particles exhibit different reaction rates, depending on where the particle originated (for example, volcanic, mesospheric, wildfire, etc.). Further, the rate is strongly correlated with common stratospheric tracer molecules, such as N2O, allowing for new methods of inputting the reaction rate into current global models of ozone. In doing so, our results suggest modeled ozone changes on the scale of single percent — comparable to the scale of observed decadal-time-scale changes in stratospheric O₃.