著者

Satoshi Iizuka Ryuichi Kawamura Hisashi Nakamura Toru Miyama

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.17A-004, (Released:2020-12-21)

被引用文献数

10

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Typhoon Hagibis (2019) caused widespread flooding and damage over eastern Japan. The associated rainfall maxima were primarily observed on the windward mountain slopes along with the west of the leading edge of a low-level front. Concomitantly, a significant positive value in sea surface temperature anomalies (SSTAs) was observed in association with an ocean eddy over the Oyashio region, together with anomalous warmth over the entire western North Pacific. The present study examines the role of the SSTAs in the rainfall distribution associated with Hagibis, to deepen our understanding of the influence of the midlatitude ocean on tropical cyclones and associated rainfall. Our sensitivity experiments demonstrate that the observed warm SSTAs had the potential to displace the rainfall caused by Hagibis inland and thereby acted to increase precipitation along the Pacific coast of northeastern Japan. Our results suggest that midlatitude SSTAs on ocean-eddy scales can also influence the synoptic-scale atmospheric front and associated heavy rainfall.

著者

Eigo Tochimoto Satoshi Iizuka Tadayasu Ohigashi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.18A, no.Special_Edition, pp.1-7, 2022 (Released:2022-02-11)

参考文献数

24

被引用文献数

5

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The influence of an upper-level trough on a Baiu frontal depression (BFD) that caused a heavy rainfall event in southern Kyushu, Japan, on July 4, 2020, was examined using numerical simulations with and without the upper-level trough. The numerical simulation with the upper-level trough (CNTL) reproduced a reasonable well-developed BFD and heavy rainfall in southern Kyushu. Conversely, the numerical simulation without the upper-level trough (NOUT) produced a weaker BFD and notable southward rainfall shift compared with the situation in the CNTL. The weaker BFD for the NOUT was due to weaker convection than that of the CNTL over mainland China. Thus, strong convection over mainland China was essential for the formation and development of the BFD that caused heavy rainfall in southern Kyushu. Additional sensitivity experiments, in which the strength of the upper-level potential vorticity anomalies was reduced to 75, 50, and 25% of the CNTL, showed that the spatial rainfall distribution shifted southward and resulted in a change in precipitation amounts in southern Kyushu because of the weakening of the BFD.

著者

Eigo Tochimoto Satoshi Iizuka Tadayasu Ohigashi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.18A-001, (Released:2022-01-25)

被引用文献数

5

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The influence of an upper-level trough on a Baiu frontal depression (BFD) that caused a heavy rainfall event in southern Kyushu, Japan, on July 4, 2020, was examined using numerical simulations with and without the upper-level trough. The numerical simulation with the upper-level trough (CNTL) reproduced a reasonable well-developed BFD and heavy rainfall in southern Kyushu. Conversely, the numerical simulation without the upper-level trough (NOUT) produced a weaker BFD and notable southward rainfall shift compared with the situation in the CNTL. The weaker BFD for the NOUT was due to weaker convection than that of the CNTL over mainland China. Thus, strong convection over mainland China was essential for the formation and development of the BFD that caused heavy rainfall in southern Kyushu. Additional sensitivity experiments, in which the strength of the upper-level potential vorticity anomalies was reduced to 75, 50, and 25% of the CNTL, showed that the spatial rainfall distribution shifted southward and resulted in a change in precipitation amounts in southern Kyushu because of the weakening of the BFD.

著者

Satoshi Iizuka Ryuichi Kawamura Hisashi Nakamura Toru Miyama

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.17A, no.Special_Edition, pp.21-28, 2021 (Released:2021-02-23)

参考文献数

19

被引用文献数

10

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Typhoon Hagibis (2019) caused widespread flooding and damage over eastern Japan. The associated rainfall maxima were primarily observed on the windward mountain slopes along with the west of the leading edge of a low-level front. Concomitantly, a significant positive value in sea surface temperature anomalies (SSTAs) was observed in association with an ocean eddy over the Oyashio region, together with anomalous warmth over the entire western North Pacific. The present study examines the role of the SSTAs in the rainfall distribution associated with Hagibis, to deepen our understanding of the influence of the midlatitude ocean on tropical cyclones and associated rainfall. Our sensitivity experiments demonstrate that the observed warm SSTAs had the potential to displace the rainfall caused by Hagibis inland and thereby acted to increase precipitation along the Pacific coast of northeastern Japan. Our results suggest that midlatitude SSTAs on ocean-eddy scales can also influence the synoptic-scale atmospheric front and associated heavy rainfall.

著者

Trismidianto Tri Wahyu Hadi Sachinobu Ishida Qoosaku Moteki Atsuyoshi Manda Satoshi Iizuka

出版者

(公社)日本気象学会

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.12, pp.6-11, 2016 (Released:2016-01-25)

参考文献数

26

被引用文献数

23

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This study analyzed the oceanic convective systems that induced heavy rainfall over the western coast of Sumatra on 28 October 2007. The convective systems that satisfied the definition of a mesoscale convective complex (MCC), as identified by infrared satellite imagery, developed repeatedly for 16 hours over the Indian Ocean near Sumatra. The MCC developed from midnight on 27 October until the early morning of 28 October, and it was intensified by the land breeze from Sumatra. New convective systems around the decaying MCC were generated during the daytime of 28 October, and they propagated to the western coast of Sumatra in the evening because of a divergent outflow from a cold pool. The combination of the land breeze from Sumatra and cold pool outflows from the decaying MCC was a significant factor in the formation of the convective system that induced strong rainfall up to 46 mm h−1 over the western coast of Sumatra.

著者

Yuiko Matsuura Satoshi Iizuka Keisuke Koizumi Keisuke Okuno Koji Kaneoka

出版者

Japan Society of Physical Education, Health and Sport Sciences

雑誌

International Journal of Sport and Health Science (ISSN:13481509)

巻号頁・発行日

pp.201820, (Released:2019-01-31)

参考文献数

13

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Trunk stabilization exercises improve injury prevention and performance, but the effect of deep trunk muscle training for underwater competitive performance and posture has not been clarified. If trunk stability can be obtained immediately after trunk stabilization exercises, such exercises may lead to performance improvements during underwater swimming and improve lumbar lordosis alignment during swim motions. The purpose of this study was to clarify the immediate effects of deep trunk muscle training on lumbar lordosis angle and swimming speed in underwater motion. The trial examined underwater motion before and after two different types and intensities of trunk stabilization exercises (low-intensity and high-intensity). Underwater motion was observed with an underwater high-speed camera placed 7.5 m from the pool wall, while lumbar lordosis angle was measured from the angle formed by markers affixed to the Th12, L3, and S1. During the glide swim, dolphin kick, and flutter kick trials, the maximum lumbar lordosis angle was calculated. Lumbar lordosis angle and swimming speed were calculated before and after two different intensities of trunk exercise interventions. There were significant differences in lumbar lordosis angle after both exercises during all three underwater motions. The high-intensity intervention elicited a significantly lower lumbar lordosis angle during glide swim, dolphin kick, and flutter kick, while swimming velocity was also improved during glide swim and flutter kick (P<0.05). Performing trunk exercise before practice or competition may help improve competition performance by reducing underwater resistance.

著者

Hiroshi Akuzawa Atsushi Imai Satoshi Iizuka Naoto Matsunaga Koji Kaneoka

出版者

The Society of Physical Therapy Science

雑誌

Journal of Physical Therapy Science (ISSN:09155287)

巻号頁・発行日

vol.28, no.12, pp.3458-3462, 2016 (Released:2016-12-27)

参考文献数

19

被引用文献数

4 17

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[Purpose] The purpose of the study was to assess the muscle activity change of the tibialis posterior, flexor digitorum longus, and peroneus longus during gait with orthoses. [Subjects and Methods] Sixteen healthy males participated in this study. Activity of each muscle was measured by using fine-wire and surface electromyography. Gait task was performed by the participants barefoot, with footwear and with orthoses. The electromyography data from a stance phase of each gait trial were used for analysis. The stance phase was divided into contact, midstance, and propulsion phases. The data from ten participants were extracted for final analysis, as electromyography measurements were unsuccessful for the other six. [Results] The results demonstrated that orthoses significantly reduced the tibialis posterior muscle activity in the propulsion phase compared to that in the barefoot condition. Although there was a significant difference in the midstance phase, post hoc analysis did not indicate significant differences among the phases. No significant electromyography amplitude change was detected in flexor digitorum longus and peroneus longus. [Conclusion] Orthothes reduced the tibialis posterior activity level during gait. This result may be beneficial for patients with injuries related to excessive activity of tibialis posterior.

著者

Toshiharu Tsutsui Toshihiro Maemichi Satoshi Iizuka Suguru Torii

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.9, no.1, pp.15-20, 2020-01-25 (Released:2020-01-21)

参考文献数

8

被引用文献数

1

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The purpose of this study was to clarify the development pattern of batting imagery in youth baseball players. One hundred thirty-eight young baseball players (6–14 years old) were divided into 4 age groups. Tee and toss batting with a stationary tee stand and toss machine were used in the batting trials. In addition, the participants did an imagery task of hitting the optimal point of a ball where they wanted to impact it. To clarify the difference between the image trial and actual batting (tee and toss), the absolute error distance (AED) was calculated by subtracting the impact distance of the image trial from that of the actual batting. Two-way analysis of variance (4 age groups × tee and toss images) revealed that the AED was significantly lower in the 11- to 12-year-old players than in the 6- to 8-year-old players (p < 0.001). The relationships between the tee and toss images showed a significant correlation in all 4 groups (6–8 years old: r = 0.445, 9–10 years old: r = 0.495, 11–12 years old: r = 0.589, and 13–14 years old: r = 0.804; all groups: p < 0.001) and that tee and toss batting imagery appears unchanged as age increases. However, batting imagery seems to develop around 11-12 years old, and at the age group of 13-14 years old players are able to impact the same position on the bat regardless of the batting trials.