日本地球惑星科学連合2018年大会

講演情報

[EE] 口頭発表

セッション記号 A (大気水圏科学) » A-OS 海洋科学・海洋環境

[A-OS12] 陸域海洋相互作用

2018年5月22日(火) 09:00 〜 10:30 106 (幕張メッセ国際会議場 1F)

コンビーナ:山敷 庸亮(京都大学大学院総合生存学館)、升本 順夫(東京大学大学院理学系研究科)、Behera Swadhin(Climate Variation Predictability and Applicability Research Group, Application Laboratory, JAMSTEC, 3173-25 Showa-machi, Yokohama 236-0001、共同)、佐々木 貴教(京都大学 大学院理学研究科 宇宙物理学教室)、座長:山敷 庸亮(京都大学大学院総合生存学館)、Swadhin Behera(海洋研究開発機構)

09:30 〜 09:45

[AOS12-03] Coastal Acoustic Tomography in Lake Biwa, Japan

*Wells John1内田 啓貴1 (1.立命館大学・環境都市工学科)

キーワード:音響トモグラフィー、到達時間の差分、深い流れの測定法の開発

We will present results from a test of Coastal Acoustic Tomography (CAT) in Lake Biwa, Japan in November 2017. Three 5 kHz transducers were deployed along a 10.2 km line from the West Shore of the lake to Takeshima. Acoustic travel times between transducers are computed from correlograms of the emitted "M11" quasi-random code with the received signal. Small but consistent differences in travel times between reciprocal paths were observed, whence we estimate path-averaged currents along the dominant acoustic path on the order of 5 cm/s, which is not inconsistent with expected magnitudes at this site. For the temperature profile in November, ray paths pass almost entirely below the thermocline. To our knowledge this is the first reported estimate of currents by Acoustic Tomography in a lake.
In the latter part of the presentation, plans for a followup three-month test scheduled to start in late July 2018 will be presented. We solicit suggestions for designing this and future tests to best contribute to understanding of Continental-Coastal Ocean interactions.