Growth and Equilibrium Morphology of Hydrohalite (NaCl·2H2O) and Its Epitaxy with Hexagonal Ice Crystals

2021 ◽  
Author(s):  
Dino Aquilano ◽  
Marco Bruno ◽  
Linda Pastero ◽  
Stefano Ghignone
Keyword(s):  
Ice Crystals ◽  
Hexagonal Ice ◽  
Equilibrium Morphology

Backscattering by hexagonal ice crystals

1999 ◽  
Author(s):  
Edward I. Naats ◽  
Anatoli G. Borovoi ◽  
Ulrich G. Oppel
Keyword(s):  
Ice Crystals ◽  
Hexagonal Ice

Backscattering by hexagonal ice crystals with large distortion angles

2018 ◽  
Author(s):  
Alexander V. Konoshonkin ◽  
Natalia V. Kustova ◽  
Andrey P. Lyulyakin ◽  
Anatoli G. Borovoi ◽  
Victor Shishko
Keyword(s):  
Ice Crystals ◽  
Hexagonal Ice ◽  
Large Distortion

How big should hexagonal ice crystals be to produce halos?

1999 ◽  
Vol 38 (9) ◽  
pp. 1626 ◽  
Author(s):  
Michael I. Mishchenko ◽  
Andreas Macke
Keyword(s):  
Ice Crystals ◽  
Hexagonal Ice

Scattering phase matrix for hexagonal ice crystals computed from ray optics

1985 ◽  
Vol 24 (19) ◽  
pp. 3254 ◽  
Author(s):  
Yoshihide Takano ◽  
Kolf Jayaweera
Keyword(s):  
Ice Crystals ◽  
Ray Optics ◽  
Hexagonal Ice ◽  
Scattering Phase

scholarly journals Some effects of ice crystals on the FSSP measurements in mixed phase clouds

2012 ◽  
Vol 12 (19) ◽  
pp. 8963-8977 ◽  
Author(s):  
G. Febvre ◽  
J.-F. Gayet ◽  
V. Shcherbakov ◽  
C. Gourbeyre ◽  
O. Jourdan
Keyword(s):  
Particle Size ◽  
Mixed Phase ◽  
Ice Crystals ◽  
Crystal Surfaces ◽  
Hexagonal Ice ◽  
Ice Particles ◽  
Second Mode ◽  
Ice Production ◽  
Bulk Parameters ◽  
Mixed Phase Clouds

Abstract. In this paper, we show that in mixed phase clouds, the presence of ice crystals may induce wrong FSSP 100 measurements interpretation especially in terms of particle size and subsequent bulk parameters. The presence of ice crystals is generally revealed by a bimodal feature of the particle size distribution (PSD). The combined measurements of the FSSP-100 and the Polar Nephelometer give a coherent description of the effect of the ice crystals on the FSSP-100 response. The FSSP-100 particle size distributions are characterized by a bimodal shape with a second mode peaked between 25 and 35 μm related to ice crystals. This feature is observed with the FSSP-100 at airspeed up to 200 m s−1 and with the FSSP-300 series. In order to assess the size calibration for clouds of ice crystals the response of the FSSP-100 probe has been numerically simulated using a light scattering model of randomly oriented hexagonal ice particles and assuming both smooth and rough crystal surfaces. The results suggest that the second mode, measured between 25 μm and 35 μm, does not necessarily represent true size responses but corresponds to bigger aspherical ice particles. According to simulation results, the sizing understatement would be neglected in the rough case but would be significant with the smooth case. Qualitatively, the Polar Nephelometer phase function suggests that the rough case is the more suitable to describe real crystals. Quantitatively, however, it is difficult to conclude. A review is made to explore different hypotheses explaining the occurrence of the second mode. However, previous cloud in situ measurements suggest that the FSSP-100 secondary mode, peaked in the range 25–35 μm, is likely to be due to the shattering of large ice crystals on the probe inlet. This finding is supported by the rather good relationship between the concentration of particles larger than 20 μm (hypothesized to be ice shattered-fragments measured by the FSSP) and the concentration of (natural) ice particles (CPI data). In mixed cloud, a simple estimation of the number of ice crystals impacting the FSSP inlet shows that the ice crystal shattering effect is the main factor in observed ice production.

scholarly journals Mesoscopic surface roughness of ice crystals pervasive across a wide range of ice crystal conditions

2014 ◽  
Vol 14 (22) ◽  
pp. 12357-12371 ◽  
Author(s):  
N. B. Magee ◽  
A. Miller ◽  
M. Amaral ◽  
A. Cumiskey
Keyword(s):  
Surface Roughness ◽  
Environmental Scanning Electron Microscopy ◽  
Diffusion Chamber ◽  
Ice Crystals ◽  
Environmental Scanning ◽  
Ice Crystal ◽  
Hexagonal Ice ◽  
Wide Range ◽  
Ice Surfaces ◽  
Cloud Modeling

Abstract. Here we show high-magnification images of hexagonal ice crystals acquired by environmental scanning electron microscopy (ESEM). Most ice crystals were grown and sublimated in the water vapor environment of an FEI-Quanta-200 ESEM, but crystals grown in a laboratory diffusion chamber were also transferred intact and imaged via ESEM. All of these images display prominent mesoscopic topography including linear striations, ridges, islands, steps, peaks, pits, and crevasses; the roughness is not observed to be confined to prism facets. The observations represent the most highly magnified images of ice surfaces yet reported and expand the range of conditions in which rough surface features are known to be conspicuous. Microscale surface topography is seen to be ubiquitously present at temperatures ranging from −10 °C to −40 °C, in supersaturated and subsaturated conditions, on all crystal facets, and irrespective of substrate. Despite the constant presence of surface roughness, the patterns of roughness are observed to be dramatically different between growing and sublimating crystals, and transferred crystals also display qualitatively different patterns of roughness. Crystals are also demonstrated to sometimes exhibit inhibited growth in moderately supersaturated conditions following exposure to near-equilibrium conditions, a phenomenon interpreted as evidence of 2-D nucleation. New knowledge about the characteristics of these features could affect the fundamental understanding of ice surfaces and their physical parameterization in the context of satellite retrievals and cloud modeling. Links to supplemental videos of ice growth and sublimation are provided.

Interpretation of ATSR-2 measurements of cirrus clouds using phase functions of imperfect hexagonal ice crystals

1998 ◽  
Author(s):  
Wouter H. Knap ◽  
M. Hess ◽  
Piet Stammes ◽  
Robert B. A. Koelemeijer ◽  
Philip D. Watts
Keyword(s):  
Cirrus Clouds ◽  
Ice Crystals ◽  
Hexagonal Ice ◽  
Phase Functions
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