Visualization of structural and textural changes in the newly formed snow layer during prolonged snowfall

• Published in: Ice and Snow
• Main Authors: M. Tentyukov P., М. Тентюков П.
• Other Authors: The work was carried out under the state assignment of the V.E. Zuev Institute of Atmospheric Optics SB RAS in the framework of project II.10.3.2, registration № АААА-А17- 117021310142-5., Работа выполнена по Государственному заданию Института оптики атмосферы им. В.Е. Зуева СО РАН в рамках проекта II.10.3.2, регистрационный № АААА-А17117021310142-5.
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: IGRAS 2021
• Subjects: snow structure;snow texture;snow micromorphology;snow stratigraphy;optical anisotropy;diffuse light reflection; структура снега;текстура снега;микроморфология снега;стратиграфия снега;оптическая анизотропия;диффузное отражение света; Annals of Glaciology; Polar Research; The Cryosphere
• Online Access: https://ice-snow.igras.ru/jour/article/view/890; https://doi.org/10.31857/S2076673421020083

Observations were made on the dynamics of structural and textural transformations in the newly fallen snow layer during its transition to a stratigraphically significant snow accumulation layer. To visualize the structural and textural transformations during a prolonged snowfall and post-sedimentation changes in it after the snowfall stopped, a reflective screen was used in combination with photomicrography of solid precipitation and snow grains. Observations were made for seven days. Already on the third day, with the thickness of the newly formed snow layer of 12 cm, the primary texture in the form of internal layering, due to the microstructure of freshly fallen snow, began to differ in it. In the process of post-sedimentation transformations, the primary stratification in the newly formed stratigraphically significant snow layer was preserved, but became less noticeable. Micrographs showed that the deposited snowflakes were transformed by sublimation metamorphism to form small rounded RGsr particles, which differed little from the snow grains in the underlying layer. It is assumed that the structural and textural post-sedimentation transformations of solid precipitation in the upper part of the snow thickness are more controlled by the depth of penetration of the air temperature gradient. Lower boundary of this upper part is well distinguished in the snow profile owing to the optical anisotropy of the snow horizons composed of RGsr snow grains and FCso and DHla facet crystals. The performed studies demonstrated that the light-reflecting screen can be used in snow science as a simple tool for optical monitoring of structural heterogeneities of seasonal snow cover and visualization of post-sedimentation processes that occur during its growth. На примере наблюдений нарастания снежной толщи во время длительного снегопада охарактеризованы особенности проявления структурно-текстурных неоднородностей в новообразующемся снежном слое по диффузному отражению света в оптическом диапазоне спектра. Показана область ...