Integrated Analysis of Airborne In-situ Cloud and Aerosol Microphysics Data during the 2022 Chemistry in the Arctic: Clouds, Halogens, and Aerosols (CHACHA) Field Campaign

The Chemistry in the Arctic: Clouds, Halogens, and Aerosols (CHACHA) field project based out of Utqiaġvik, Alaska in February-April 2022 featured a wide collaboration from six universities in order to enhance the scientific understanding of multiphase halogen chemistry in the Arctic. This understanding will in turn fortify our understanding of how atmospheric halogen chemistry is affected by Arctic sea ice loss, as well as fossil fuel extraction activities.

In this poster, observations from the University of Wyoming King Air are evaluated closely to assess the ambient conditions relevant to the Arctic boundary layer during flights targeting clouds emanating from open leads in the Arctic sea ice. Aerosol microphysics data from instruments including a Condensation Particle Counters (CPC), Portable Optical Particle Spectrometer (POPS), and Passive Cavity Aerosol Spectrometer Probe (PCASP) and cloud microphysics data from a Cloud Droplet Probe (CDP) and Two-Dimensional Stereo (2D-S) probe are used. In addition, instruments on the aircraft recorded geo-location and pressure altitude data. Dropsonde and satellite data, to assess the 3-D environment sampled during these flights, were obtained in preparation for future modeling studies. These results will provide insights in the aerosol and cloud microphysics in the understudied and changing Arctic troposphere. Diagnostic measurements from the Counterflow Virtual Impactor (CVI) and Particle into Liquid Sampler (PILS) are further used to evaluate the sampling conditions under which each of the samples were obtained. This study will support future offline chemical analysis of the low volume (1.5 mL) PILS samples by providing a methodological basis for prioritizing samples and identifying samples that can be safely grouped together when additional sample volume is required. Ultimately, this work will help to constrain a Lagrangian chemical box model and cloud parcel modeling to better understand multiphase Arctic halogen chemistry.