{"title":"Fabrication of an Infrared Hygrometer Using an Optical Beam Splitter","authors":"S. Onogi, Akihiro Hori","doi":"10.2467/MRIPAPERS.58.95","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.95","url":null,"abstract":"近年、チューナブル・ダイオード・レーザーやLEDなどの半導体光源が赤外線吸収湿度計に使用され始めているが、これらの半導体光源を使用した赤外線湿度計は１波長方式であり、雲生成実験槽内に氷晶やエーロゾルが存在した状態では湿度を正常に測定することができない。このような状態でも湿度を測定可能とする方法として、赤外線領域での吸収波長と、その近傍の非吸収波長をリファレンスとして利用することにより、チリなどの浮遊粒子による測定誤差を補正できる２波長方式があるが、この方式は２つの波長で同一の測定体積を測定する必要がある。半導体光源を使用して２波長方式の赤外線湿度計を製作するには、それぞれ異なる半導体から射出された２つの波長の光束を合成して１本の光束とする必要があり、これは製作上の困難を伴う。これに対して白熱灯光源は１つの光源で２波長方式に必要な２つの波長の光を含んでいるので、このような困難は伴わない。 そこで、氷晶やエーロゾルが存在した状態でも雲生成実験槽内の湿度を測定できる２波長方式の赤外線湿度計の開発を目的とし、今回はそのプロトタイプとして、室内環境において湿度測定が可能であり、白熱灯を光源とし、２つの波長の測定部にビームスプリッタを使用し、測定パスが可変の赤外線湿度計を製作した。使用波長は水蒸気によって吸収される波長として1.9μm、水蒸気に吸収されないリファレンス用の波長として1.6μmとした。 約700mmから約4000mmの３つの測定パスについて、恒湿槽にて校正を行ったが、周囲の温度変動が±2℃程度と小さい状態においては、製作した湿度計が相対湿度として誤差±5％以内の精度を持つことが確認できた。 今後は、雲生成実験槽内の低温低圧の状態でも湿度が測定できるよう高性能化を進めるとともに、実験槽への取付方法についても検討する必要がある。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"392 1","pages":"95-101"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Occurrence order simulation of the Tonankai and the Nankai earthquakes using a plate-subduction model with two asperities","authors":"H. Takayama, H. Kuroki, K. Maeda","doi":"10.2467/MRIPAPERS.58.127","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.127","url":null,"abstract":"すべり速度・状態依存摩擦構成則を平面および３次元の形状をしたプレート境界面に適用し，東南海および南海地震の発生順序に関するシミュレーションを行った。平面のプレート境界では，プレートの形状の影響がないので，東南海・南海地震のそれぞれのアスペリティの大きさおよび摩擦係数（a-b）の大きさの影響を調べた。アスペリティの大きさおよびa-bの絶対値が同じ場合（基本モデル）は，どちらかが先に起こる傾向は見られないことがわかった。アスペリティの大きさまたはa-bの絶対値が異なる場合は，いずれも小さい方が先に起きた。前者は応力の集中の早さの違いに起因し，後者は応力降下量の大きさの違いに起因する。プレート境界を３次元の形状にした場合についてもシミュレーションを行った。東南海と南海のアスペリティの大きさとa-bの大きさを同じにし，両アスペリティのa-bの絶対値を基本モデルと同じにした場合は東南海から先に起き，10%小さくすると南海から先に起こるようになった。これは東南海の東端からの応力の集中の早さと紀伊半島沖の安定すべりによる南海側での応力集中の早さの関係がa-bの値の大小で入れ替わるためと考えられる。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"58 1","pages":"127-134"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Tanimoto, Y. Sawa, H. Matsueda, S. Yonemura, A. Wada, H. Mukai, Tao Wang, S. Poon, Anson Wong, Gangwoong Lee, Jin-young Jung, Kyung-Ryul Kim, Meehye Lee, N. Lin, Jia‐Lin Wang, C. Ou-Yang, Chuann-Fang Wu
An international exercise to directly assess the consistency of standards and methods for measuring carbon monoxide (CO) was conducted as part of the East Asian Regional Experiment 2005 (EAREX 2005) in the framework of the Atmospheric Brown Clouds (ABC) project. Four groups representing Japan, Korea, Hong Kong, and Taiwan made comparisons at the Gosan super-site on Jeju Island, Korea, in March 2005, by setting up individual instruments with gas standards which are commonly used in ground-based monitoring programs in Asia. Intensive comparisons between two Japanese groups showed that a non-dispersive infrared absorption (NDIR) instrument agreed fairly well with a gas chromatograph / reduction gas detector (GC/RGD) with 1-h time resolution, confirming that NDIR methods are useful for monitoring, in particular, large temporal variations of CO in ambient air. Although international comparison of ambient measurements by NDIR indicated general agreement, comparison of gas standards revealed difficulties in preparing accurate and stable standard gases for monitoring CO at ambient levels.
{"title":"Evaluation of standards and methods for continuous measurements of carbon monoxide at ground-based sites in Asia","authors":"H. Tanimoto, Y. Sawa, H. Matsueda, S. Yonemura, A. Wada, H. Mukai, Tao Wang, S. Poon, Anson Wong, Gangwoong Lee, Jin-young Jung, Kyung-Ryul Kim, Meehye Lee, N. Lin, Jia‐Lin Wang, C. Ou-Yang, Chuann-Fang Wu","doi":"10.2467/MRIPAPERS.58.85","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.85","url":null,"abstract":"An international exercise to directly assess the consistency of standards and methods for measuring carbon monoxide (CO) was conducted as part of the East Asian Regional Experiment 2005 (EAREX 2005) in the framework of the Atmospheric Brown Clouds (ABC) project. Four groups representing Japan, Korea, Hong Kong, and Taiwan made comparisons at the Gosan super-site on Jeju Island, Korea, in March 2005, by setting up individual instruments with gas standards which are commonly used in ground-based monitoring programs in Asia. Intensive comparisons between two Japanese groups showed that a non-dispersive infrared absorption (NDIR) instrument agreed fairly well with a gas chromatograph / reduction gas detector (GC/RGD) with 1-h time resolution, confirming that NDIR methods are useful for monitoring, in particular, large temporal variations of CO in ambient air. Although international comparison of ambient measurements by NDIR indicated general agreement, comparison of gas standards revealed difficulties in preparing accurate and stable standard gases for monitoring CO at ambient levels.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"58 1","pages":"85-93"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2467/MRIPAPERS.58.85","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Evaluation of Seasonal Cycles of Hydrological Processes in Japan Meteorological Agency Land Data Analysis","authors":"T. Nakaegawa, Takayuki Tokuhiro, Akira Itoh, M. Hosaka","doi":"10.2467/MRIPAPERS.58.73","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.73","url":null,"abstract":"本研究では、気象庁陸面解析システムと河川モデルからなるシステム(LDAG)により得られる、3つの水文量、土壌水分量、河川流量、陸水総貯留量の季節変化の気候値を観測値と比較して、その再現性を評価した。LDAGの土壌水分量は観測値に対して殆どの地点で高い相関を示した。しかし、中緯度東ユーラシア大陸では、負の相関も見られた。降水量の再現性は高いので、他の強制力、観測地点と異なる植生種類の使用などが原因と考えられる。河川流量は、多くの流域で20%以上の振幅の違いがあり、特に、北極海に注ぐ河川の多くでは、振幅が半分程度しかなかった。対象とした70河川中、過半数の河川で相関係数が0.5以上となった。多くの流域で位相差は±1ヶ月程度で、良く合っていた。観測に対して位相が遅い流域は6つだけで、位相が早い系統誤差がみられた。LDAGの再現性は小さくいないものの、類似のモデルと同程度の定性的な再現性を有していることが確認された。陸水総貯留量については、大流域河川のうち、アマゾン河、ミシシッピー河、レナ河では振幅の誤差は±10%以下であり良く再現している。一方、季節変化の相関係数は、熱帯やアジアモンスーン地域に位置する河川を中心に相関係数が高い流域が見られるが、総じて低い。これは、上述の人為的影響の他に、湖沼による滞留効果等が影響していると考えられる。位相差は、河川流量と同じく、観測に対して位相が遅い流域は4つに過ぎなく、それ以外の多くの流域で位相が早くなっている。特にコンゴ河と北極海に注ぐ河川で位相が3ヶ月も早くなっている。以上から、LDAGの水文量の季節変化は、観測気候値の基本的な特徴をかなり再現している。ただし、上に述べたように、問題点もあるので、それらを認識した上で、LDAGの水文量を、全球モデルの陸面初期値として利用したり、水文過程の研究に活用したりすることは許容されるであろう。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"58 1","pages":"73-83"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Establishment of Precision of Calculation for Volcanic Crustal Deformation by FEM","authors":"T. Sakai, Tetsuya Yamamoto, K. Fukui, Kenji Fujiwara, A. Takagi, M. Churei","doi":"10.2467/MRIPAPERS.58.1","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.1","url":null,"abstract":"火山における地殻変動を解釈する場合、半無限均質弾性体内の充分小さな球圧力源による地表面変位を表す山川（1955）による解析解など、非常に単純化された状況から導出された解析解が用いられている。しかしながら、現実の火山においては、地表面上に突出する火山地形の存在や、球形以外の圧力源形状、あるいは不均質な地下構造などのため、そのような解析解は厳密には成り立たない。そこで我々は、現実の火山における地殻変動の様子をより詳しく知るため、有限要素法（FEM）を用いて数値モデルを作成し、計算を進めている。その際、モデル領域の大きさや境界条件の設定などが火山性地殻変動の計算精度に影響を及ぼすことが予想される。そこで、本研究では、茂木-山川モデルをFEモデルで再現し、モデル領域の大きさや境界条件が火山性地殻変動の計算精度に及ぼす影響について定量的に評価した。その結果、以下のような知見が得られた。モデル領域を大きくするほど、FE解析結果は山川の解に近付き、火山性地殻変動の計算精度を高めることができる。しかしながら、モデル領域を大きくするほど一般に節点数が多くなり、計算時間が加速度的に増大することから、必要な計算精度が確保される範囲内でなるべく小さなモデル領域を設定するのが良い。境界条件については、計算精度の距離変化の様子が上下変位と水平変位で最も類似することから、モデル領域の底面と外周面を完全固定するのが最も良いと考えられる。モデル領域の深さ方向の大きさは上下変位の計算精度に、また、モデル領域の水平方向の大きさは水平変位の計算精度に大きな影響を及ぼす。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"58 1","pages":"1-15"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2007-01-01DOI: 10.2467/MRIPAPERS.58.103
A. Wada
When tropical cyclone (TC) intensity is predicted using a sophisticated numerical model under a given initial condition with a typhoon bogus, numerical problems, particularly associated with the tendency errors, arise as well as problems related to the intensity limitation due to relatively coarse horizontal resolution. In order to investigate the problems, numerical experiments are performed for nine TCs in the western North Pacific from 2000 to 2002 using the typhoon model (TYM) and typhoon-ocean coupled model (CTYM). CTYM reduces the overdevelopment that occurs in the later integration predicted by TYM due to local sea surface cooling caused by the passage of TCs. However, CTYM hardly improves the tendency errors that occur in the early integration. The errors are found in all predictions using CTYM with each of the three physical schemes and have different characteristics for typhoons Bilis (2000), Wutip (2001), and Phanfone (2002). The TC thermodynamic structures of Wutip also differ from the three predictions using CTYM with each of the three schemes even at almost the same integration time and central pressure. Under the steady-state assumption, we estimate the maximum potential intensity (MPI) for three schemes and two TCs from the two-dimensional axisymmetrical mean structure. Assuming that the MPI is estimated from the net gain energy through the isothermal process scale-analyzed from the Colioris force and adiabatic process from the centrifugal force, it is found that predominance of convective available potential energy due to the adiabatic process leads to the underdevelopment of TCs. The improvement of physical schemes in CTYM is planned for the underdevelopment: revising a surface boundary formulation or introducing a sophisticated planetary boundary formulation contributes to increasing the energy caused by the isothermal process, while revising the precipitation or cumulus parameterization contributes to reducing the energy caused by the adiabatic process.
{"title":"Numerical Problems Associated with Tropical Cyclone Intensity Prediction Using a Sophisticated Coupled Typhoon-Ocean Model","authors":"A. Wada","doi":"10.2467/MRIPAPERS.58.103","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.103","url":null,"abstract":"When tropical cyclone (TC) intensity is predicted using a sophisticated numerical model under a given initial condition with a typhoon bogus, numerical problems, particularly associated with the tendency errors, arise as well as problems related to the intensity limitation due to relatively coarse horizontal resolution. In order to investigate the problems, numerical experiments are performed for nine TCs in the western North Pacific from 2000 to 2002 using the typhoon model (TYM) and typhoon-ocean coupled model (CTYM). CTYM reduces the overdevelopment that occurs in the later integration predicted by TYM due to local sea surface cooling caused by the passage of TCs. However, CTYM hardly improves the tendency errors that occur in the early integration. The errors are found in all predictions using CTYM with each of the three physical schemes and have different characteristics for typhoons Bilis (2000), Wutip (2001), and Phanfone (2002). The TC thermodynamic structures of Wutip also differ from the three predictions using CTYM with each of the three schemes even at almost the same integration time and central pressure. Under the steady-state assumption, we estimate the maximum potential intensity (MPI) for three schemes and two TCs from the two-dimensional axisymmetrical mean structure. Assuming that the MPI is estimated from the net gain energy through the isothermal process scale-analyzed from the Colioris force and adiabatic process from the centrifugal force, it is found that predominance of convective available potential energy due to the adiabatic process leads to the underdevelopment of TCs. The improvement of physical schemes in CTYM is planned for the underdevelopment: revising a surface boundary formulation or introducing a sophisticated planetary boundary formulation contributes to increasing the energy caused by the isothermal process, while revising the precipitation or cumulus parameterization contributes to reducing the energy caused by the adiabatic process.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"30 1","pages":"103-126"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multidecadal Variability of the Upper Ocean Heat Content Anomaly Field in the North Pacific and its Relationship to the Aleutian Low and the Kuroshio Transport","authors":"T. Hasegawa, T. Yasuda, K. Hanawa","doi":"10.2467/MRIPAPERS.58.155","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.155","url":null,"abstract":"北太平洋において、数十年スケールの海洋表層貯熱量の変動特性とアリューシャン低気圧、黒潮流量、北太平洋亜熱帯モード水のコア水温、海面水温、海面気圧との関係について調べた。その結果、表層貯熱量偏差は北太平洋中緯度において時計回りに伝播していることがわかった。また、この伝播が1980年以降においてアリューシャン低気圧、黒潮流量、北太平洋亜熱帯モード水のコア水温と連動して変化することが示された。すなわち、アリューシャン低気圧が強化した約5年後に黒潮流量が増加し、さらに数年後に、北太平洋亜熱帯モード水のコア水温および日本の南東海域における海洋表層貯熱量偏差が増加する。このような関係は、過去の研究で指摘された20年スケールにおける関係と類似する。また、海洋表層貯熱量の伝播経路上において、表層貯熱量偏差、海面水温偏差、海面気圧偏差が同期する領域は、日本の南東海域と太平洋中央部を含む黒潮続流域の東方海域のみであることが明らかになった。さらに、表層貯熱量の伝播特性がこの領域で強化されることが明らかになった。本研究の結果から、北太平洋の数十年スケールにおける海洋表層貯熱量の時間空間変動特性や、それと関係する大気海洋偏差場との関連について新しい知見が得られた。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"43 1","pages":"155-166"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Long-term changes of temperature extremes and day-to-day variability in Japan","authors":"F. Fujibe, Nobuo Yamazaki, Kenji Kobayashi, H. Nakamigawa","doi":"10.2467/MRIPAPERS.58.63","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.58.63","url":null,"abstract":"日本における極端な高低温の長期・短期変動を，75 年間（1931～2005）の17 地点の日最高・最低気温と45 年間（1961～2005）の12 地点の850hPa 気温データを使って調べた。解析では平年値からの偏差について，月間最高値・最低値・平均値と日々変動幅（月内標準偏差）を扱った。また，標準偏差の2 倍以上の偏差が現れる頻度も調べた。その結果，日最高気温については月間最高値・最低値・平均値がほぼ並行して上昇していること，上昇率は近年ほど大きいこと，日々変動幅にはほとんど長期変化がないことが見出された。ほぼ同じことは850hPa 気温にも当てはまる。一方，日最低気温は月間最低値の上昇率が大きく，日々変動幅は減少している。また，極端な高低温には短期的な変動があり，それは平均値と日々変動幅の双方の変動と対応している。ラグ相関解析と主成分分析の結果によると，日々変動幅の偏差は数ヶ月～1 年程度の継続性があり，南北温度傾度の変動と対応関係がある。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"58 1","pages":"63-72"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study addresses the changes in the probability density function (PDF) of the 500-hPa geopotential heights during El Nino and La Nina events using the dynamical seasonal hindcasts made at the National Center for Environmental Prediction. First, two-way layout analysis of variance (ANOVA) is applied to the hindcasts to assess the effects of lead time on the simulated climatological mean and variance. Results demonstrate that there is no statistically significant effect of lead time in DJF. However, there is a significant effect of lead time on the climatological mean for JJA over northeastern China, due to the initial soil wetness. This effect on anomalies can be eliminated by using the climatological mean with different lead times. Based on this analysis, we combined four 10-member ensembles with different lead times to increase the ensemble members to 40, which allows us to examine the statistical significance of the change in the PDF. We applied non-parametric Kolmogorov-Smirnov tests to the changes for the El Nino and La Nina events. Results indicate that the changes in the PDF are significant during these events over most of the globe and have unique features for each event, but the major factor is the change in the mean.
{"title":"Changes in the probability density function of 500-hPa geopotential heights during El Nino and La Nina events","authors":"敏之 仲江川, 正郎 金光","doi":"10.2467/MRIPAPERS.56.25","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.56.25","url":null,"abstract":"This study addresses the changes in the probability density function (PDF) of the 500-hPa geopotential heights during El Nino and La Nina events using the dynamical seasonal hindcasts made at the National Center for Environmental Prediction. First, two-way layout analysis of variance (ANOVA) is applied to the hindcasts to assess the effects of lead time on the simulated climatological mean and variance. Results demonstrate that there is no statistically significant effect of lead time in DJF. However, there is a significant effect of lead time on the climatological mean for JJA over northeastern China, due to the initial soil wetness. This effect on anomalies can be eliminated by using the climatological mean with different lead times. Based on this analysis, we combined four 10-member ensembles with different lead times to increase the ensemble members to 40, which allows us to examine the statistical significance of the change in the PDF. We applied non-parametric Kolmogorov-Smirnov tests to the changes for the El Nino and La Nina events. Results indicate that the changes in the PDF are significant during these events over most of the globe and have unique features for each event, but the major factor is the change in the mean.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"1 1","pages":"25-33"},"PeriodicalIF":0.0,"publicationDate":"2006-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Experiments related to twentieth century historical climate changes and the twenty-first century scenario are performed with the latest version of the MRI climate model, MRI-CGCM2.3. The model reproduces globally averaged surface air temperature (SAT) variations in the twentieth century with satisfactory agreement with interdecadal changes of the observed trend, as well as with the overall SAT increase of 0.5°C at the present-day compared to the pre-industrial level. The globally averaged SAT rises 2.4°C in the late twenty-first century in the experiment for scenario A1B of the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The spatial structures of the simulated trends for the late twentieth century are validated in various atmospheric fields through comparisons with observed data, which indicate that the model demonstrates reasonable agreement with the observed trend in each field. Most of the simulated changes for the twenty-first century reveal spatial patterns similar to those in the trends that appeared in the late twentieth century. The simulated trend patterns of the sea-level pressure (SLP) in both hemispheres bear a resemblance to the observed trends, with each spatial structure reminiscent of the annular modes in the northern and southern hemispheres (NAM and SAM). These SLP trend patterns are consistent with the trends in the SAT, precipitation, and zonal mean zonal wind fields, as in the NAM and SAM. The coherent trend structures of these fields are projected to be enhanced in twenty-first century climate changes. Changes of ocean and sea-ice in association with these atmospheric changes are also described.
{"title":"Climate changes of the twentieth through twenty-first centuries simulated by the MRI-CGCM2.3","authors":"誠史 行本, 彰子 野田, 貴雄 内山, 昌司 楠, 昭雄 鬼頭","doi":"10.2467/MRIPAPERS.56.9","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.56.9","url":null,"abstract":"Experiments related to twentieth century historical climate changes and the twenty-first century scenario are performed with the latest version of the MRI climate model, MRI-CGCM2.3. The model reproduces globally averaged surface air temperature (SAT) variations in the twentieth century with satisfactory agreement with interdecadal changes of the observed trend, as well as with the overall SAT increase of 0.5°C at the present-day compared to the pre-industrial level. The globally averaged SAT rises 2.4°C in the late twenty-first century in the experiment for scenario A1B of the Special Report on Emissions Scenarios (SRES) by the Intergovernmental Panel on Climate Change (IPCC). The spatial structures of the simulated trends for the late twentieth century are validated in various atmospheric fields through comparisons with observed data, which indicate that the model demonstrates reasonable agreement with the observed trend in each field. Most of the simulated changes for the twenty-first century reveal spatial patterns similar to those in the trends that appeared in the late twentieth century. The simulated trend patterns of the sea-level pressure (SLP) in both hemispheres bear a resemblance to the observed trends, with each spatial structure reminiscent of the annular modes in the northern and southern hemispheres (NAM and SAM). These SLP trend patterns are consistent with the trends in the SAT, precipitation, and zonal mean zonal wind fields, as in the NAM and SAM. The coherent trend structures of these fields are projected to be enhanced in twenty-first century climate changes. Changes of ocean and sea-ice in association with these atmospheric changes are also described.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"56 1","pages":"9-24"},"PeriodicalIF":0.0,"publicationDate":"2006-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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