Texture characterization of some large hailstones with an automated technique

• Published in: Journal of Glaciology
• Main Authors: Montagnat, Maurine, Bourcier, Mathieu, Philip, Armelle, Bons, Paul, Bauer, Catherine, Deconinck, Paul, Hereil, Pierre
• Other Authors: Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Centre d'Etudes de la Neige (CEN), Centre national de recherches météorologiques (CNRM), Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Météo France-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Eberhard Karls University of Tübingen, Department of Geosciences, Applied Mineralogy, Wilhelmstraße 56, 72074 Tübingen, Germany, Thiot ingénierie, Puybrun
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Journal of Glaciology
• Online Access: https://hal.archives-ouvertes.fr/hal-03409459; https://hal.archives-ouvertes.fr/hal-03409459/document; https://hal.archives-ouvertes.fr/hal-03409459/file/Montagnat2021_TexturesLargeHailstones.pdf; https://doi.org/10.1017/jog.2021.66

International audience Abstract Hailstone structures have been studied for over a century, but so far mainly by manual optical means. This paper presents new texture and microstructure data (i.e. crystal lattice orientations, grain sizes and shapes) measured with an Automatic Ice Texture Analyzer, which gives access to high spatial and angular resolutions. The hailstones show two main characteristics: (1) they are structured with several concentric layers composed of alternating fine equiaxed grains and coarse elongated and radially oriented grains, and (2) they show two texture types with c -axes oriented either parallel or perpendicular to the radial direction. Such textures are compared with the ones observed in lake S1 and S2 ices, respectively. The S1 texture type (with c -axes parallel to the columnar crystals that grew in the radial direction) may result from epitaxial growth from a polycrystalline embryo, while the S2 texture ( c -axes in the plane perpendicular to the column direction) may result from the growth from an embryo made of a few crystals with mainly one crystallographic orientation. Our novel high-resolution maps and measurements of both microstructure and texture may help to shed new light on the long-term discussion on the growth mechanisms of large hailstones.