Microphysical Consequences of the Spatial Distribution of Ice Nucleation in Mixed-Phase Stratiform Clouds

Journal Article · Mon Jul 28 04:00:00 EDT 2014 · Geophysical Research Letters, 41(14):5280–5287

DOI:https://doi.org/10.1002/2014GL060657· OSTI ID:1171310

Yang, Fan; Ovchinnikov, Mikhail; Shaw, Raymond A.

Mixed-phase stratiform clouds can persist even with steady ice precipitation fluxes, and the origin and microphysical properties of the ice crystals are of interest. Vapor deposition growth and sedimentation of ice particles along with a uniform volume source of ice nucleation, leads to a power law relation between ice water content wi and ice number concentration ni with exponent 2.5. The result is independent of assumptions about the vertical velocity structure of the cloud and is therefore more general than the related expression of Yang et al. [2013]. The sensitivity of the wi-ni relationship to the spatial distribution of ice nucleation is confirmed by Lagrangian tracking and ice growth with cloud-volume, cloud-top, and cloud-base sources of ice particles through a time-dependent cloud field. Based on observed wi and ni from ISDAC, a lower bound of 0.006 m^3/s is obtained for the ice crystal formation rate.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1171310
• Report Number(s): PNNL-SA-103506; KP1701000
• Journal Information: Geophysical Research Letters, 41(14):5280–5287, Journal Name: Geophysical Research Letters, 41(14):5280–5287
• Country of Publication: United States
• Language: English

Related Subjects

ice precipitation fluxes
mixed-phase stratiform clouds