CAPE-K_ISO

Water Vapor Isotopic Measurements During CAPE-K

15 April 2024 - 15 September 2025

Lead Scientist: Joseph Galewsky

Observatory: AMF (ARM Mobile Facility 2) - KCG

The CAPE-k_Iso project enhances the Cloud And Precipitation Experiment at kennaook (CAPE-k) through continuous monitoring of water vapor isotopic composition at the kennaook/Cape Grim Baseline Air Pollution Station in Tasmania. Using a Picarro cavity ring-down spectroscopy isotope analyzer, we measure δ18O and δD in atmospheric water vapor with high temporal resolution. These isotopic measurements provide crucial insights that support CAPE-k's primary objectives by: (1) serving as sensitive tracers of moisture sources and atmospheric transport pathways across the Southern Ocean, enabling better characterization of air mass history; (2) constraining cloud microphysical processes through isotopic fractionation signatures during phase changes, particularly in the formation and evolution of pristine marine clouds; (3) helping distinguish between local evaporation and long-range transport contributions to observed water vapor, critical for accurate aerosol-cloud-precipitation interaction studies; and (4) providing validation data for isotope-enabled climate models to improve representation of the hydrological cycle over this climatically significant region.