INPULSE

INP Understanding through Local Sampling Enhancement

9 August 2026 - 30 September 2026

Lead Scientist: Sylvia Sullivan

Observatory: AMF (ARM Mobile Facility 1) - DST

The INP Understanding through Local Sampling Enhancement, or INPULSE, small campaign requests daily measurement frequency with the ARM Ice Nucleation Spectrometer and the Profiling Upper altitudes for Ice Nucleation platform at the Main Site during the monsoon 2026 Intensive Observation Period of the DUSTIEAIM field campaign. The currently planned, ground-based measurements every six days are insufficient to capture the episodic nature of dust events, for example due to outflow boundaries, mining or construction activity, or rapid changes in surface winds. Biological or vegetative particles may play a secondary role in the ice-nucleating activity over southern Arizona, but these emissions will again tend to be localized in time due to intermittent convective rain or short-lived heatwaves that induce plant stress. Daily and vertically resolved collections will better capture the temporal variability in INP concentrations over the Phoenix area, facilitating studies that translate this INP variability to changes in cloud and precipitation properties. In addition, we request this increased sampling to overlap with the DROPLET experiment in which microscopic and spectrometric analyses will be run on filters collected from the ARM tethered balloon system. The combination of more frequent ground-based INP spectra and more detailed aerosol data during DROPLET will allow researchers to identify any relationships in INP activity across altitudes or between INP activity and specific particle properties, such as coating or morphology.