日本地球惑星科学連合2019年大会

講演情報

[J] ポスター発表

セッション記号 A (大気水圏科学) » A-AS 大気科学・気象学・大気環境

[A-AS06] ミクロスケール気象の稠密観測・数値モデリングの新展開

2019年5月26日(日) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:伊藤 純至(東京大学大気海洋研究所)、荒木 健太郎(気象研究所)、古本 淳一(京都大学生存圏研究所)、東 邦昭(京都大学生存圏研究所・メトロウェザー株式会社)

[AAS06-P06] 低コスト吹雪観測装置の複数台連携による風速測定

*小林 ゆい1,2渡辺 恭也1,3成瀬 延康1,4高橋 幸弘1,5 (1.北海道大学グローバルサイエンスキャンパス、2.東北大学理学部、3.北海道大学工学部、4.滋賀医科大学医学部、5.北海道大学大学院理学研究院)

キーワード:吹雪、防災、装置開発

Poor-visibility with the blowing snow sometimes causes serious troubles such as car crashes. Previously we reported the development of a low-cost visibility meter, which estimates visibility quantitatively, measuring the reduction of laser intensity caused by the laser blocking by snow particles. Those laser intensity data together with ambient temperature are sent to a personal computer via a wireless network. The remarkable characteristic of this apparatus is a very compact body, achieving enough length of the light path by reflecting laser light three times by mirrors facing each other. We confirmed the performance as poor-visibility meter, by investigating the correlation between the reduction of laser intensity and the visibility simultaneously recorded by the conventional video system.
In regard to wind speed, which is essential in order to predict poor-visibility caused by blowing snow, conventional propeller-type anemometer has been used up to now. However, such propeller anemometer has moving parts so that the low-cost type lacks durability. On the other hand, the hot-wire and thermocouple type anemometer needs relatively high-power consumption. In this study we developed a new methodology for wind speed measurement using densely placed visibility meters, making use of the time difference between the snow particle passing at different apparatus. Experiments were performed using a wind tunnel at Cryospheric Environment Simulator of the Shinjo Branch (Snow and Ice Research Center, National Research Institute for Earth Science and Disaster Resilience). The three units of the visibility meter were set at an interval of 4-5 m in the wind tunnel and connected with a computer for data collections by wireless communication. The time interval of data sampling was set to 0.5 s. The propeller type anemometer to measure the wind speed as a reference was set downstream of the three observation units. The wind speed can be measured by detecting the delay time for snow particles to move from one unit to the next one. The wind speed obtained by our system was 8.8 m s-1, being averaged for data obtained at three points, while the wind speed measured by the anemometer was 9.1 m s-1. These results mean only with this poor-visibility meter network we can estimate the wind velocity with an accuracy of 3 percent.