edu.ucar.opensky::articles:26453 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T19:30:52.071222 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7862mfq Stability analysis of ice crystal orientation 2023-06-01T00:00:00Z publication https://n2t.org/ark:/85065/d7862mfq https://doi.org/10.1175/JAS-D-22-0223.1 Zeng, X. author Ulanowski, Z. author Heymsfield, Andrew J. author Wang, Y. author Li, X. author UCAR/NCAR - Library publisher The stability of ice crystal orientation is studied by modeling the airflow around ice crystals at moderate Reynolds number, where an ice crystal is approximated by a cylinder with three parameters: diameter D, length L, and zenith angle of the axis O. In this paper, the torque acting on ice crystals is simulated at different O first, and then a special O with zero horizontal torque, denoted as Oe, is sought as an equilibrium of ice crystal orientation. The equilibrium is classified into two kinds: stable and unstable. Ice crystals rotate to Oe of stable equilibriums while deviating from Oe of unstable ones once they are released into quiet air. Multiple equilibriums of ice crystal orientation are found via numerical simulations. A cylinder with D/L close to one has three equilibriums, two of which are stable (i.e., Oe = 0 DEG; and 90 DEG;). A cylinder with D/L away from one has only two equilibriums, one of which is stable (i.e., either Oe = 0 DEG; or 90 DEG;). In addition, an asymmetric cylinder has two, three, or five equilibriums, and their Oe is sensitive to the distance between its geometrical center and its center of gravity. The sensitivity of Oe to crystal asymmetry suggests large symmetric ice crystals tend to become asymmetric (or irregular) and subsequently oriented randomly. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2023 American Meteorological Society (AMS). None eng geoscientificInformation