How do Cloud Macrostructure and Weather Pattern Modulate the Removal of Ice Nucleating Particles and Stable Isotopes in Precipitation?

Precipitation collected at the Earth's surface, while primarily comprised of the molecule H2O16, contains significant heterogeneous material that has recorded the history of the hydrometeors, from vapor to condensate to cloud particles to precipitation. The use of stable water isotopes as a way to quantitatively evaluate the efficient removal of INPshas received significant attention recently, with some authors proposing that the efficiency of removal of atmospheric water vapor and the temperature of INP activation in the same weather system are related. Here, we present detailed chemical analysis of individual insoluble precipitation residues and the stable isotope composition of water (δ18O and δD) in time-resolved precipitation collected in atmospheric rivers in Northern California during winter 2016. Using size-resolved drop freezing spectra, nano-particle tracking analysis, ion chromatography and single particle aerosol mass spectrometry in concert with synoptic meteorological analysis and profiles of S-band radar reflectivity, we examine the relationships between insoluble residues, their ice nucleating properties, stable isotopes, cloud macrostructure and synoptic weather patterns. In particular, we will address the role meteorology plays in modulating the preferential removal of ice nucleating particles during atmospheric rivers.