著者

YOSHINO Katsumi

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

pp.2019-023, (Released:2018-12-13)

被引用文献数

12

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Aircrafts making landing and takeoff at Narita International Airport (Narita Airport) in Japan report frequently low-level wind shear (LLWS), a local variation of wind vector, with turbulence when the prevailing wind is southwesterly, which is crosswind to the runway direction. On 20 June 2012, an arrival aircraft at Narita Airport encountered a LLWS, which consisted of a sudden change of the wind vector from head wind component of 5 knots (2.6 m s-1) to tail wind component of 10 knots (5.1 m s-1), just before the touchdown and made a hard landing. None of cumulonimbus clouds, a front or a wind shear line was observed around the airport during her approaching and landing. Analyses of the data measured by the landing aircraft and the observations by the Doppler lidar at the airport revealed that the LLWS was caused by horizontal roll vortices, which developed in the atmospheric boundary layer (ABL) over the Shimofusa Tableland around the airport. The horizontal roll vortices had their axes nearly parallel to the mean wind direction, and their horizontal and vertical scales were approximately 800 m and 500 m, respectively. The present study demonstrated that existence of the horizontal roll vortices causing LLWS can be effectively detected by a single-Doppler lidar which utilizes backscattering from aerosols. Although the LLWS associated with the horizontal roll vortices has smaller magnitude than those caused by a microburst, a gust front and a front, a landing aircraft just before touchdown encounters the horizontal roll vortices with much higher probability than the other phenomena mentioned here since the horizontal roll vortices occurs at a horizontal spacing of approximately 800 m over a wide area during daytime of a clear day.

著者

Araki Hisashi * Anvar Saiki Eiji Yamasaki Nobuo Yakushi Kyuya Yoshino Katsumi

出版者

社団法人応用物理学会

雑誌

Japanese journal of applied physics. Pt. 2, Letters (ISSN:00214922)

巻号頁・発行日

vol.34, no.8, pp.L1041-L1044, 1995-08-15

参考文献数

22

被引用文献数

16

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Superconductivity in poly(3-alkylthiophene)- C60 composite (PAT- C60) is found upon doping by potassium from vapor phase. The superconducting (SC) transition at T C=17 K is detected by superconducting quantum interference device (SQUID), which showed 0.8% of SC fraction for C60 content of 5 mol%. An exceptionally strong low-field microwave absorption (LFMA) implies the existence of granular SC phase. A rather small hysteresis of LFMA indicates the important role of the Josephson weak link network, probably formed between SC K xC60 clusters separated by conductive K xPAT barriers. ESR of PAT(C60) yK x composite shows two types of lines: one from negative polarons P- in PAT chains, and another assigned to K xC60 clusters and C1-60 radical.