Search Results 1-20 of 252

  • Prediction of Large Forecast Error of Solar Irradiance by Variation of Forecast Weather Parameters using WRF Models with Different Physical Schemes  [in Japanese]

    舟見 翔太 , 今中 政輝 , 栗本 宗明 , 杉本 重幸 , 加藤 丈佳 , 宇野 史睦

    電気学会研究会資料. FTE = The papers of Technical Meeting on "Frontier Technology and Engineering", IEE Japan 2021(1-8), 39-46, 2021-03-05

  • Predictability of the July 2018 Heavy Rain Event in Japan Associated with Typhoon Prapiroon and Southern Convective Disturbances

    Honda Takumi , Miyoshi Takemasa

    … This study investigated the predictability of this precipitation event using a regional ensemble data assimilation system. … A series of daily ensemble forecast experiments showed that the forecast ensemble spread during the heavy precipitation event increased in the forecasts initialized on July 1 and July 3. …

    SOLA, 2021

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  • Factors for an Abrupt Increase in Track Forecast Error of Typhoon Hagibis (2019)

    Nakashita Saori , Enomoto Takeshi

    … <p>The predictability of Typhoon Hagibis in October 2019 is examined with ensemble forecasts from four major operational numerical weather prediction centers. … From six to four days before the landfall, the forecast from the Japan Meteorological Agency was the best among the four centers. … The ensemble sensitivity analysis for the landing region indicates a large sensitivity to a ridge located to the southeast of the typhoon. …

    SOLA 17A(Special_Edition), 33-37, 2021

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  • Predictability of Enhanced Monsoon Trough Related to the Meandered Asian Jet and Consequent Rossby Wave Breaking in Late August 2016

    TAKEMURA Kazuto , ENOMOTO Takeshi , MUKOUGAWA Hitoshi

    <p> 2016年8月下旬に日本の南海上の対流圏下層で発達した、大規模な低気圧を伴うモンスーントラフの予測可能性を調べた。このモンスーントラフはアジアジェットの蛇行、及びそれに伴う日本の東海上でのロスビー波の砕波と関連する上層での高渦位大気の南西方向への侵入によって強化されたことが分かった。気象庁現業1か月アンサンブル予報は、予測初期1週間においてロスビー波の砕波の強度を過小に予測し、 …

    Journal of the Meteorological Society of Japan. Ser. II 99(2), 339-356, 2021

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  • Relaxation Experiments for Predictability Assessment of Enhanced Monsoon Trough in Late August 2016

    TAKEMURA Kazuto , MUKOUGAWA Hitoshi

    <p> 2016年8月後半に、ユーラシア大陸上でのロスビー波束伝播及びそれに伴う日本の東海上における高気圧性のロスビー波の砕波に伴って、モンスーントラフが日本の南海上で強化した。本研究では、このモンスーントラフ強化の予測可能性を、大気大循環モデルを用いた緩和予報実験の手法により評価した。緩和予報実験では、日本の東海上の砕波域、ユーラシア大陸上の波束伝播域、及び両領域の計3つの領域におけ …

    Journal of the Meteorological Society of Japan. Ser. II 99(2), 459-472, 2021

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  • Use of Meso-ensemble Prediction System for Renewable Power Forecast and its Future Task  [in Japanese]

    Ohtake Hideaki

    … <p>Solar power and wind power forecast include prediction uncertainty. … Recently, the Japan Meteorological Agency (JMA) developed meso-ensemble prediction system (MEPS) and has been operated the MEPS since June 2019. … This paper explains an ensemble forecast and describe the future use of the MEPS data in an energy management system with the renewable energy fields (e.g., solar power and wind power).</p> …

    IEEJ Transactions on Power and Energy 141(4), 287-290, 2021

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  • Forecasts of the July 2020 Kyushu Heavy Rain Using a 1000-Member Ensemble Kalman Filter

    Duc Le , Kawabata Takuya , Saito Kazuo , Oizumi Tsutao

    … <p>Forecast performances of the July 2020 Kyushu heavy rain have been revisited with the aim of improving the forecasts for this event. … While the Japan Meteorological Agency's (JMA) deterministic forecasts were relatively good, the JMA's ensemble forecasts somehow missed this event. …

    SOLA 17(0), 41-47, 2021

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  • Dam Flood Control Operation Based on Ensemble Rainfall Forecast  [in Japanese]

    INOMATA Hironori , KAWASAKI Masaki , KUDO Shun

    <p> 洪水時のダム操作において利用される予測雨量は,一つの初期条件・境界条件等に基づく確定的な予測雨量が従来から用いられてきている.予測雨量の精度は予測技術の進展に伴い向上してきており,これからも向上することが期待される.しかしその一方で,予測誤差を完全に無くすことは難しく不確実性が不可避であると考えられるため,洪水時ダム操作における予測雨量の活用においても,従来の確定的な予測雨量に …

    JOURNAL OF JAPAN SOCIETY OF HYDROLOGY AND WATER RESOURCES 34(1), 24-53, 2021

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  • Factors for an Abrupt Increase in Track Forecast Error of Hagibis 2019  [in Japanese]

    中下 早織 , 榎本 剛

    … We have investigated the quality of track forecast for Typhoon Hagibis 2019 using ensemble forecast data from four major operational numerical weather forecast centers, ECMWF, NCEP, UKMO, and JMA. … From six to four days before the landfall, the JMA forecast was the best among other centers, but the error increased sharply three days before the landfall. …

    京都大学防災研究所年報. B = Disaster Prevention Research Institute Annuals. B 63(B), 227-232, 2020-12

    IR 

  • A candidate secular variation model for IGRF-13 based on MHD dynamo simulation and 4DEnVar data assimilation

    Minami Takuto , Nakano Shin'ya , Lesur Vincent , Takahashi Futoshi , Matsushima Masaki , Shimizu Hisayoshi , Nakashima Ryosuke , Taniguchi Hinami , Toh Hiroaki

    … We adopt an ensemble-based assimilation scheme, called four-dimensional ensemble-based variational method (4DEnVar), which linearizes outputs of MHD dynamo simulation with respect to the deviation from a dynamo state vector at an initial condition. … For SV prediction, we first generate an ensemble of dynamo simulation results from a free dynamo run. …

    Earth, Planets and Space 72(1), 136, 2020-09-21

    IR 

  • Ensemble flood simulation for a small dam catchment in Japan using nonhydrostatic model rainfalls - Part 2: Flood forecasting using 1600-member 4D-EnVar-predicted rainfalls

    Kobayashi Kenichiro , Duc Le , Apip , Oizumi Tsutao , Saito Kazuo

    … This paper is a continuation of the authors' previous paper (Part 1) on the feasibility of ensemble flood forecasting for a small dam catchment (Kasahori dam; … approx. 70 km(2)) in Niigata, Japan, using a distributed rainfall-runoff model and rainfall ensemble forecasts. … The ensemble forecasts were given by an advanced four-dimensional, variational-ensemble assimilation system using the Japan Meteorological Agency nonhydrostatic model (4D-EnVar-NHM). …

    Natural Hazards and Earth System Sciences 20(3), 755-770, 2020-03-23

    IR 

  • Impact of Satellite Observations on Forecasting Sudden Stratospheric Warmings

    Noguchi S. , Kuroda Y. , Mukougawa H. , Mizuta R. , Kobayashi C.

    … The observational impacts of satellite data assimilation on extended‐range forecasts of sudden stratospheric warmings (SSWs) are investigated by conducting ensemble forecast experiments. … A comparative examination on the reproducibility for SSWs between the two ensemble forecasts reveals that the impact of satellite observations is significant for forecasts starting 5 days before the SSW onset, with 20% less accuracy in the JRA‐55C forecasts. …

    Geophysical Research Letters 47(5), 2020-03-16

    IR 

  • Does Ensemble Learning Always Lead to Better Forecasts?

    Hamori Hitoshi , Hamori Shigeyuki

    Ensemble learning is a common machine learning technique applied to business and economic analysis in which several classifiers are combined using majority voting for better forecasts as compared to those of individual classifier. … This study presents a counterexample, which demonstrates that ensemble learning leads to worse classifications than those from individual classifiers, using two events and three classifiers. …

    Applied Economics and Finance 7(2), 51-56, 2020-03

    IR 

  • Evaluation and uncertainty investigation of the NO2, CO and NH3 modeling over China under the framework of MICS-Asia III

    Kong Lei , Tang Xiao , Zhu Jiang , Wang Zifa , Fu Joshua S. , Wang Xuemei , Itahashi Syuichi , Yamaji Kazuyo , Nagashima Tatsuya , Lee Hyo-Jung , Kim Cheol-Hee , Lin Chuan-Yao , Chen Lei , Zhang Meigen , Tao Zhining , Li Jie , Kajino Mizuo , Liao Hong , Wang Zhe , Sudo Kengo , Wang Yuesi , Pan Yuepeng , Tang Guiqian , Li Meng , Wu Qizhong , Ge Baozhu , Carmichael Gregory R.

    … All models significantly underpredicted CO concentrations in both the NCP and PRD regions, with annual mean concentrations that were 65.4 % and 61.4 % underestimated by the ensemble mean. … This suggests that for some highly active and/or short-lived primary pollutants, like NH3, model uncertainty can also take a great part in the forecast uncertainty in addition to the emission uncertainty. …

    Atmospheric Chemistry and Physics 20(1), 181-202, 2020-01-06

    IR 

  • Forecasting technology of surface solar irradiance and photovoltaics power generation for smart grid : Utilization forecasting probability information using ensemble forecast  [in Japanese]

    宇野 史睦

    スマートグリッド : 技術雑誌 = Smart grid : technical journal 10(1), 54-58, 2020-01

  • STORM SURGE PREDICTION WITH ENSEMBLE WEATHER FORECAST  [in Japanese]

    園田 彩乃 , 宇都宮 好博 , 松藤 絵理子 , 鈴木 隆宏 , 内田 洋平 , 鈴木 善光 , 内田 裕之

    海洋開発シンポジウム講演集 45, 6p, 2020

  • APPLICABILITY OF ECMWF MEDIUM-RANGE ENSEMBLE RAINFALL FORECAST TO PRIOR RELEASE OPERATION OF A HYDROPOWER DAM  [in Japanese]

    野原 大督 , 木谷 和大 , 道広 有理 , 角 哲也

    水工学論文集 Annual journal of Hydraulic Engineering, JSCE 65, Ⅰ_829-834, 2020

  • FLOOD RISK ANALYSIS OF THE ARA RIVER DURING THE TYPHOON NO.19 IN 2019 BASED ON HINDCAST AND ENSEMBLE FORECAST RAINFALL DATA  [in Japanese]

    伊藤 毅彦 , 尾形 勇紀 , 佐山 敬洋 , 片岡 智哉 , 小野村 史穂 , 二瓶 泰雄

    水工学論文集 Annual journal of Hydraulic Engineering, JSCE 65, Ⅰ_769-774, 2020

  • EVALUATION OF HEAVY RAINFALL RISK OF TYPHOON HAGIBIS ASSOCIATED WITH TYPHOON TRACK  [in Japanese]

    HOSHINO Tsuyoshi , OKACHI Hiroki , TAKEHARA Yui , YAMADA Tomohito J.

    <p> 本研究は甚大な被害を引き起こした令和元年台風19号(令和元年東日本台風,以下,台風19号)の降雨の特徴を台風の経路と降雨量の関係から分析した.過去の台風,台風19号のアンサンブル予報実験,大量アンサンブル気候データを用いた分析を実施し,それぞれ台風の経路と降雨量の関係,数日スケールの予測からの台風19号の潜在的な降雨量,降雨量の温暖化の進行の影響を評価した.過去の台風事例を用い …

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 76(1), 414-423, 2020

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  • RESERVOIR OPERATION AGAINST FLOODS DUE TO TYPHOON HAGIBIS AND APPLICABILITY OF ENSEMBLE FORECAST TO PRIOR RELEASE  [in Japanese]

    NOHARA Daisuke , SUMI Tetsuya

    <p> 2019年10月12日に伊豆半島に上陸した令和元年台風第19号は,東日本を中心とした広い範囲に豪雨をもたらし,各地でダムの洪水調節操作が実施された.本稿では,当該出水における東日本のダム洪水調節操作の状況について概観し,大規模出水時におけるダム洪水調節の効果や課題について検討する.次に,記録的な豪雨となった相模川水系のダム洪水調節の状況と効果について詳しく分析する.さらに,大規 …

    Journal of Japan Society of Civil Engineers, Ser. B1 (Hydraulic Engineering) 76(1), 212-222, 2020

    J-STAGE 

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