著者

Akihiko Shimpo Kazuto Takemura Shunya Wakamatsu Hiroki Togawa Yasushi Mochizuki Motoaki Takekawa Shotaro Tanaka Kazuya Yamashita Shuhei Maeda Ryuta Kurora Hirokazu Murai Naoko Kitabatake Hiroshige Tsuguti Hitoshi Mukougawa Toshiki Iwasaki Ryuichi Kawamura Masahide Kimoto Izuru Takayabu Yukari N. Takayabu Youichi Tanimoto Toshihiko Hirooka Yukio Masumoto Masahiro Watanabe Kazuhisa Tsuboki Hisashi Nakamura

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.15A, pp.13-18, 2019 (Released:2019-06-15)

参考文献数

22

被引用文献数

80

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An extreme rainfall event occurred over western Japan and the adjacent Tokai region mainly in early July, named “the Heavy Rain Event of July 2018”, which caused widespread havoc. It was followed by heat wave that persisted in many regions over Japan in setting the highest temperature on record since 1946 over eastern Japan as the July and summertime means. The rain event was attributable to two extremely moist airflows of tropical origins confluent persistently into western Japan and large-scale ascent along the stationary Baiu front. The heat wave was attributable to the enhanced surface North Pacific Subtropical High and upper-tropospheric Tibetan High, with a prominent barotropic anticyclonic anomaly around the Korean Peninsula. The consecutive occurrence of these extreme events was related to persistent meandering of the upper-level subtropical jet, indicating remote influence from the upstream. The heat wave can also be influenced by enhanced summertime convective activity around the Philippines and possibly by extremely anomalous warmth over the Northern Hemisphere midlatitude in July 2018. The global warming can also influence not only the heat wave but also the rain event, consistent with a long-term increasing trend in intensity of extreme precipitation observed over Japan.

著者

Akihiko Shimpo Kazuto Takemura Shunya Wakamatsu Hiroki Togawa Yasushi Mochizuki Motoaki Takekawa Shotaro Tanaka Kazuya Yamashita Shuhei Maeda Ryuta Kurora Hirokazu Murai Naoko Kitabatake Hiroshige Tsuguti Hitoshi Mukougawa Toshiki Iwasaki Ryuichi Kawamura Masahide Kimoto Izuru Takayabu Yukari N. Takayabu Youichi Tanimoto Toshihiko Hirooka Yukio Masumoto Masahiro Watanabe Kazuhisa Tsuboki Hisashi Nakamura

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.15A-003, (Released:2019-05-17)

被引用文献数

80

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An extreme rainfall event occurred over western Japan and the adjacent Tokai region mainly in early July, named “the Heavy Rain Event of July 2018”, which caused widespread havoc. It was followed by heat wave that persisted in many regions over Japan in setting the highest temperature on record since 1946 over eastern Japan as the July and summertime means. The rain event was attributable to two extremely moist airflows of tropical origins confluent persistently into western Japan and large-scale ascent along the stationary Baiu front. The heat wave was attributable to the enhanced surface North Pacific Subtropical High and upper-tropospheric Tibetan High, with a prominent barotropic anticyclonic anomaly around the Korean Peninsula. The consecutive occurrence of these extreme events was related to persistent meandering of the upper-level subtropical jet, indicating remote influence from the upstream. The heat wave can also be influenced by enhanced summertime convective activity around the Philippines and possibly by extremely anomalous warmth over the Northern Hemisphere midlatitude in July 2018. The global warming can also influence not only the heat wave but also the rain event, consistent with a long-term increasing trend in intensity of extreme precipitation observed over Japan.

著者

Ryoya Hirata Toshihiko Hirooka Masato Yoshida Masataka Nakazawa

出版者

The Institute of Electronics, Information and Communication Engineers

雑誌

IEICE Electronics Express (ISSN:13492543)

巻号頁・発行日

vol.16, no.23, pp.20190664, 2019 (Released:2019-12-10)

参考文献数

30

被引用文献数

2 5

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We present a wavelength-tunable ultrafast optical switch using a nonlinear optical loop mirror (NOLM), which has a low walk-off characteristic between the signal pulse and the control pulse thanks to the use of a dispersion-flattened highly nonlinear fiber. A 400-fs switching speed and an extinction ratio of >32 dB were obtained from 1528 to 1565 nm. The NOLM was applied to the 320 to 40 Gbaud demultiplexing of DQPSK Nyquist pulse signals, and error-free operation was achieved over the entire C-band.