著者

北畠 尚子 津口 裕茂

出版者

Japan Meteorological Agency / Meteorological Research Institute

雑誌

Papers in Meteorology and Geophysics (ISSN:0031126X)

巻号頁・発行日

vol.68, pp.1-19, 2020 (Released:2020-10-16)

参考文献数

17

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本研究では、2016年8月31日に日本海で974 hPaまで深まった低気圧について、JRA-55再解析データを用いて解析を行う。この低気圧は台風第10号(T1610、アジア名Lionrock)を吸収して発達したように見えた。この日本海の低気圧の深まりは、比較的弱い傾圧帯で生じ、上部対流圏の高渦位空気が傾斜した等温位面上を南東・下方へ移動してきたのに伴っていた。対流圏の中・下層の昇温も地上低気圧の深まりに寄与していた。低気圧の発達の最終段階には、上層トラフとT1610とのカップリングが生じた。T1610は、日本海の低気圧の発達初期にも、台風とその北の高気圧との間の南東風で下層湿潤空気を日本海へ輸送することで、低気圧発達に寄与した。日本海における潜熱解放は、その北東側の上層リッジを強化することでその後面のトラフとの間の渦度移流を強化することでも、日本海の低気圧の発達に寄与したと考えられる。

著者

K. Saruhashi

出版者

Japan Meteorological Agency / Meteorological Research Institute

雑誌

Papers in Meteorology and Geophysics (ISSN:0031126X)

巻号頁・発行日

vol.6, no.1, pp.38-55, 1955-08-30 (Released:2012-12-11)

参考文献数

10

被引用文献数

16 29

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It is of importance to study the behaviour of carbonic acid substances dissolved in natural water in order to know the chemical properties of the water. Acidity or alkalinity method has been generally used for this purpose for a long time. But this method often leads to erroneous results.The present auth or proposed that a better way is to determine first the amount of total carbonic acid, pH and temperature, and then to calculate theoretically the amount of H2CO3, HCO3- and CO3- using equilibrium constants between them.However, such a calculation is too laborious for every analyst, and therefore the author completed tables convenient for use containing calculated values of molar fractions of each carbonic acid substance for different temperature and pH in fresh water and sea water. In these tables, one can find any necessary values of molar fraction when the total amount of carbonic acid, temperature and pH of waters are given. By the use of this method, exact determination of the amount of each carbonic acid substance in water is made possible.

著者

T. Kizawa

出版者

Japan Meteorological Agency / Meteorological Research Institute

雑誌

Papers in Meteorology and Geophysics (ISSN:0031126X)

巻号頁・発行日

vol.8, no.2, pp.150-169, 1957-11-30 (Released:2012-12-11)

参考文献数

33

被引用文献数

3 3

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Showa-Shinzan, one of th e Belonite-Volcanoes, born (1943-1945)in the eastern part of the Volcano Usu (in the South-western part of Hokkaido, Japan) is famous in the history of volcanoes in the world.This volcano erupted in a farm-land and further developed a lava dome (Spine) in the central part. It is a Pelée-type one, and its developing process was clearly observed for the whole period.Some remarkable earthquake swarms occurred during the volcanic activity, and the major ones among them were recorded by seismographs even at a station about 800 km apart from the volcano.The author investigated the relations betwee n the occurrence of earthquakes and the formation of Showa-Shinzan and tried to find some clues to the volcanic mechanism. In this first paper, after an investigation of the characteristics of earthquake swarms recorded on the seismographs in Muroran, Mori and Sapporo (epicentral distance: 25-69 km) and the relation of the volcanic activity therewith, some interesting results were obtained:1) Daily earthquake frequency diagram for the whole period of twenty three months were prepared for the first time.2) These earthquakes were clearly divided into the following three stages:( i ) Pre-volcanic stage: In this stage there was no eruption, and remarkable earthquakes occurred around Volcano Usu frequently. The relation between the maximum amplitude (A) in these earthquake swarms and their frequency (N) was expressed byNAm = const.where m is about 1.8, similar to that of the tectonic earthquake. Moreover, the migration of the hypocentres of these earthquakes showed an intimate connection with the course of the magma intrusion.(ii) Stage of eruptive activity: A violent eruption occurred in the central part of the rising area. The extremely shallow earthquakes during the period of six months including just before and through the eruptive activity were proved to have been originated at the area adjacent to the newly formed crater.(iii) Birth and developmen t of lava dome (spine): The lava dome grew and developed without eruption, accompanied with numerous earthquakes. The earthquakes, which differed greatly from those at the former two stages, began to occur almost simultaneously with the end of the eruption and the frequencies of the earthquakes during the following twelve months corresponded closely to the speed of the development of the lava dome. The value of m in this case was 3.5.3) Process of magma intrusion, increase of magma viscosity a n d their relationship with the feature change of earthquake swarms were investigated. The possibility of predicting volcanic activity Volcano Usu by seismograph at stations up to approximately sixty or seventy kilometers from the volcano is suggested.

著者

小林 昭夫

出版者

Japan Meteorological Agency / Meteorological Research Institute

雑誌

Papers in Meteorology and Geophysics (ISSN:0031126X)

巻号頁・発行日

vol.69, pp.1-14, 2021 (Released:2021-01-21)

参考文献数

31

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Kobayashi(2017)は、GNSSデータの共通ノイズを低減し、1年間の傾斜期間を持つランプ関数との相関を取ることにより、南海トラフ沿い長期的スロースリップの客観検出を行った。ここではこの手法を応用し、南海トラフ沿い短期的スロースリップの客観的な検出を行った。GNSS日値および6時間値について長期トレンドを除き、1週間の傾斜期間を持つランプ関数との相関を取った。本手法により検出された時空間分布は、深部低周波地震の活発化とよく一致していた。また、Kobayashi(2017)は長期的スロースリップに伴う変位を検出したが、ここではその手法を応用して検出された長期的スロースリップの規模推定を行い、先行研究とほぼ一致した結果が得られた。

著者

角村 悟 西橋 政秀 楠 研一

出版者

Japan Meteorological Agency / Meteorological Research Institute

雑誌

Papers in Meteorology and Geophysics (ISSN:0031126X)

巻号頁・発行日

vol.66, pp.25-37, 2016 (Released:2016-07-04)

参考文献数

34

被引用文献数

2

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落雷に係る電荷について、東北地方庄内地域での地上電場観測に基づき調査した。最初、理論値を観測値に最小二乗法であわせるため要求される細かさについて議論した。高度0.1 km毎の電荷による理論的な電場を与え、適切な解を得るため必要となる水平方向の分解能を提案した。提案された空間分解能により2012年の暖・寒候期に庄内で発生した19の落雷に係る地上の電場により電荷の位置と量を推定した。推定された負極性落雷の電荷の推定位置の2事例を大気温度、ドップラーレーダーおよびVHF帯雷標定システムで検知された電磁波放射源の分布と比較した。1つの事例では、推定された電荷は落雷を引き起こす負電荷の性質を表していた。他方では、電荷が低高度に求まり、通常の負極性落雷モデルでは説明できなかった。本研究で記された数値的電荷推定の議論は、少ない地上電場観測を元にした落雷に関係する電荷の今後の研究にとって有効な情報になると考えられる。

著者

H. Arakawa

出版者

Japan Meteorological Agency / Meteorological Research Institute

雑誌

Papers in Meteorology and Geophysics (ISSN:0031126X)

巻号頁・発行日

vol.5, no.2, pp.114-123, 1954-11-05 (Released:2012-12-11)

参考文献数

5

被引用文献数

3 11

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Pyramidal waves in the “ eye ” of typhoons are described in many meteorological texts. Numerous exmples are given indicating that the most dangerous, pyramidal, mountainous and confused seas are those found in the right or dangerous semi-circle of typhoons and not those found in the calm center.