Development of new optical instrument for snow physical parameters using polarimetric information and its application to satellite monitoring system for cryosphere

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K00534
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Japan, Meteorological Research Institute
• Principal Investigator: Tanikawa Tomonori 気象庁気象研究所, 気象予報研究部, 主任研究官 (20509989)
• Co-Investigator(Kenkyū-buntansha): 長 幸平 東海大学, 情報理工学部, 教授 (90256199)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 偏光 / 分光観測 / 衛星観測 / 放射伝達 / 光散乱 / 積雪

Outline of Final Research Achievements

This study focuses on snow polarization properties to construct a new monitoring system of snow physical parameters. We conducted in situ polarimetric measurement using a high-precision optical instrument and developed a radiative transfer model for the atmosphere-snow-sea ice system. Results indicate that the polarimetric measurements revealed for the first time the existence of neutral points of polarization in the snow surface, and the possibility of the detection in the wet snow surface. In addition, new finding is a development of an advanced snow grain shape model seamlessly representing a geometrical shape and an optical properties of various snow types. Based on these results, we constructed the snow monitoring system using satellite data.

Free Research Field

雪氷放射学，雪氷学

Academic Significance and Societal Importance of the Research Achievements

本研究の成果は，積雪の偏光特性を定量的に明らかにし，その光学特性の理解を推し進めるものである．特に，積雪の波長別偏光特性（中立点の存在），湿雪検知の可能性，高度な光散乱粒子モデルの構築など，新しい知見を見出した．これらの結果は，衛星観測による多様な積雪物理量の観測を可能にし，将来の雪氷圏の変動予測に貢献するものである．