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Title: Monitoring water phase dynamics in winter clouds

This work presents observations of water phase dynamics that demonstrate the theoretical Wegener–Bergeron–Findeisen concepts in mixed-phase winter storms. The work analyzes vertical profiles of air vapor pressure, and equilibrium vapor pressure over liquid water and ice. Based only on the magnitude ranking of these vapor pressures, we identified conditions where liquid droplets and ice particles grow or deplete simultaneously, as well as the conditions where droplets evaporate and ice particles grow by vapor diffusion. The method is applied to ground-based remote-sensing observations during two snowstorms, using two distinct microwave profiling radiometers operating in different climatic regions (North American Central High Plains and Great Lakes). The results are compared with independent microwave radiometer retrievals of vertically integrated liquid water, cloud-base estimates from a co-located ceilometer, reflectivity factor and Doppler velocity observations by nearby vertically pointing radars, and radiometer estimates of liquid water layers aloft. This work thus makes a positive contribution toward monitoring and now casting the evolution of supercooled droplets in winter clouds.
 [1] ;  [2] ;  [3] ;  [3]
  1. Argonne National Lab. (ANL), Argonne, IL (United States)
  2. Radiometrics Corp., Boulder, CO (United States); National Center for Atmospheric Research, Boulder, CO (United States); Cooperative Institute for Research in the Environmental Science, Boulder, CO (United States)
  3. Environment Canada, Toronto, Ontario (Canada)
Publication Date:
Grant/Contract Number:
Published Article
Journal Name:
Atmospheric Research
Additional Journal Information:
Journal Volume: 147-148; Journal Issue: C; Journal ID: ISSN 0169-8095
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
Country of Publication:
United States
54 ENVIRONMENTAL SCIENCES; cloud; microwave radiometer; mixed phase; supercooled droplet; snowstorm
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1196243; OSTI ID: 1395051