We estimated an attenuation function of displacement amplitude based on moment magnitude. The function enable us to calculate conventional magnitude that would agree with moment magnitude on the average in all depth ranges. Magnitude calculated with the function is smaller than that calculated with M. Katsumata's formula by about 0.3 for deep-focus earthquakes. The function is applicable to data when the hypocentral distance is from about 30 to 2000 kilometers. The function was estimated based on data from the Japan Meteorological Agency (JMA) between January 1977 and February 1994. Some corrections are provided to apply the function to data from the current JMA seismological network developed in 1994.
{"title":"Attenuation Function of Displacement Amplitude for Magnitude Calculation.","authors":"A. Katsumata","doi":"10.2467/MRIPAPERS.50.1","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.50.1","url":null,"abstract":"We estimated an attenuation function of displacement amplitude based on moment magnitude. The function enable us to calculate conventional magnitude that would agree with moment magnitude on the average in all depth ranges. Magnitude calculated with the function is smaller than that calculated with M. Katsumata's formula by about 0.3 for deep-focus earthquakes. The function is applicable to data when the hypocentral distance is from about 30 to 2000 kilometers. The function was estimated based on data from the Japan Meteorological Agency (JMA) between January 1977 and February 1994. Some corrections are provided to apply the function to data from the current JMA seismological network developed in 1994.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"50 1","pages":"1-14"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023800","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":"Source, path, and site effects estimated from S waves observed in southern Kanto, Japan.","authors":"M. Hoshiba, Y. Yoshida, A. Katsumata, K. Maeda, Y. Ishikawa","doi":"10.2467/MRIPAPERS.49.33","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.49.33","url":null,"abstract":"南関東の4観測点にて得られた S波のスペクトルから震源特性、伝播経路特性、観測点近傍の増幅特性を分離して求めることを試みた。観測される S波のスペクトルは、震源スペクトル、S波の減衰特性 (Qs-1値)、観測点の増幅特性の積で表されると仮定し、S波加速度スペクトルを対数で表現した後、線形インバージョンを行なった。関東平野の縁部に設置された観測点では高周波において大きな増幅特性が得られた。また、Qs-1値は、3-20Hzで、-0.5乗に比例する結果となった。高周波や低周波が卓越する地震を震源スペクトルから定義して、その深さ依存性と地域依存性を調べた。深い地震の方が高周波が卓越するようであり、その傾向は太平洋プレートの地震に限れば顕著に見える。今回解析した地震からは、地域性に関してははっきりした傾向は得られなかった。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"20 1","pages":"33-42"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023421","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}
An unsteady extension of Bernoulli's theorem is presented. For steady flows, the derivative of the Bernoulli function in the normal direction perpendicular both to the streamline and the gradient of potential temperature becomes equal to the product of the flow speed and the binormal component of absolute vorticity. Even for unsteady flows, the same formula holds except that the absolute vorticity is replaced by the sum of the absolute vorticity and the local rotation rate of velocity.
{"title":"An unsteady extension of Bernoulli's theorem.","authors":"H. Kanehisa","doi":"10.2467/MRIPAPERS.49.29","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.49.29","url":null,"abstract":"An unsteady extension of Bernoulli's theorem is presented. For steady flows, the derivative of the Bernoulli function in the normal direction perpendicular both to the streamline and the gradient of potential temperature becomes equal to the product of the flow speed and the binormal component of absolute vorticity. Even for unsteady flows, the same formula holds except that the absolute vorticity is replaced by the sum of the absolute vorticity and the local rotation rate of velocity.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"49 1","pages":"29-32"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023393","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":"Asian Summer Monsoon Viewed from Energy Budget.","authors":"T. Ose","doi":"10.2467/MRIPAPERS.49.75","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.49.75","url":null,"abstract":"","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"49 1","pages":"75-101"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023746","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-Period Seismograph Magnitude of Explosion Earthquakes and B-Type Earthquakes at Sakurajima Volcano.","authors":"T. Sakai, H. Yamasato, K. Uhira","doi":"10.2467/MRIPAPERS.49.59","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.49.59","url":null,"abstract":"長周期の地震波が卓越することの多い桜島火山の爆発地震とB型地震のマグニチュードを求めることを目的として、鹿児島地方気象台の桜島の観測点E点に長周期地震計を設置した。福岡管区気象台で震源要素が決定された一般地震のデータから、この長周期地震計の上下動成分によるマグニチュードMELVの計算式を求めたところ、MELV=logAV+1.37 logΔ+0.69 が得られた。この式は福岡管区気象台で決定されたマグニチュードとの系統的な差がなく、また M4.0 までの火山性地震に対して信頼性があると考えられる。この式を適用することにより、1996年に発生した171個の爆発地震のMELVは1.3∼3.1 に決定された。また、1996年1月に発生した120個のB型地震のMELVは0.7∼1.8に決定された。同じくE点に設置している短周期地震計の上下動成分についても同様にマグニチュード計算式を求め、爆発地震とB型地震のマグニチュードを算出し、MELVと比較したところ、MELVの方が平均してそれぞれ約0.21、約0.14大きくなった。これは、長周期成分が卓趣する爆発地震やB型地震の場合、短周期地震計では本来の振幅が得られないためである。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"13 1","pages":"59-74"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023483","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}
A long-range sulfur transport model consisting of two submodels-a meteorological submodel and a dispersion submodel-has been developed to evaluate the extent of acid deposition in East Asia. The Japan Meteorology Agency's operational weather forecasting model was adopted and improved upon, and employed to predict meteorological variables. A Lagrangian particle method was used as the basis for the dispersion model, and a random walk calculation was used for the diffusion process. Dry deposition, below-cloud scavenging, and chemical transformation processes were also included. A numerical simulation was performed for the transport of sulfur oxides in East Asia in 1985, and the annual deposition was evaluated. The results of the simulation showed that the wet deposition of sulfur oxides originating from the Asian continent was roughly 0.05gS/m2/ year, and the dry deposition 0.02-0.17gS/m2/year. The observed wet deposition was about 1.0gS/m2/year, and although uncertain volcanic influence was included in this observed value, it was about 20 times lower than wet deposition of sulfur values observed in Japan. Calculated wet deposition values at four representative receptors were found to be much lower than observed values. Therefore, it was inferred that the contribution from foreign emission sources was extremely low, on the order of around ten percent. An evaluation of the impact of deposition in Kita-Kyushu (in western Japan) showed that emissions from South Korea, Taiwan and the southeastern region of China affected the Kita-Kyushu values. However, an evaluation of the impact of deposition in Niigata (on the Sea of Japan coast) showed that emissions from China dominated.
{"title":"Transport of Sulfur Oxides over the East Asian Region by the Off-line Coupled Meteorological and Transport Model.","authors":"J. Sato, H. Sasaki, T. Satomura","doi":"10.2467/MRIPAPERS.50.97","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.50.97","url":null,"abstract":"A long-range sulfur transport model consisting of two submodels-a meteorological submodel and a dispersion submodel-has been developed to evaluate the extent of acid deposition in East Asia. The Japan Meteorology Agency's operational weather forecasting model was adopted and improved upon, and employed to predict meteorological variables. A Lagrangian particle method was used as the basis for the dispersion model, and a random walk calculation was used for the diffusion process. Dry deposition, below-cloud scavenging, and chemical transformation processes were also included. A numerical simulation was performed for the transport of sulfur oxides in East Asia in 1985, and the annual deposition was evaluated. The results of the simulation showed that the wet deposition of sulfur oxides originating from the Asian continent was roughly 0.05gS/m2/ year, and the dry deposition 0.02-0.17gS/m2/year. The observed wet deposition was about 1.0gS/m2/year, and although uncertain volcanic influence was included in this observed value, it was about 20 times lower than wet deposition of sulfur values observed in Japan. Calculated wet deposition values at four representative receptors were found to be much lower than observed values. Therefore, it was inferred that the contribution from foreign emission sources was extremely low, on the order of around ten percent. An evaluation of the impact of deposition in Kita-Kyushu (in western Japan) showed that emissions from South Korea, Taiwan and the southeastern region of China affected the Kita-Kyushu values. However, an evaluation of the impact of deposition in Niigata (on the Sea of Japan coast) showed that emissions from China dominated.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"50 1","pages":"97-111"},"PeriodicalIF":0.0,"publicationDate":"1999-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023714","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}
In a vertically 2-dimensional steady adiabatic fluid system, there exists a vorticity-like conserved quantity, which is a function of the stream function. In Smith (1985)'s original model of downslope windstorm, this function is assumed to be linear, and the proportionality constant to be negative. However, the possibility of its positiveness can not be excluded. In this note, the case for the constant to be positive is examined, and the followings are shown. Also in this case, there exist solutions representing downslope windstorms. The unnatural upper bound for the atmospheric height in Smith (1985)'s solution does not emerge, and the solution may exist for any large value of the atmospheric height. The ratio of the mountain height to the atmospheric height is somewhat greater than that of Smith (1985)'s solution.
{"title":"Another Type of Downslope Windstorm in Smith's Model.","authors":"H. Kanehisa","doi":"10.2467/MRIPAPERS.49.1","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.49.1","url":null,"abstract":"In a vertically 2-dimensional steady adiabatic fluid system, there exists a vorticity-like conserved quantity, which is a function of the stream function. In Smith (1985)'s original model of downslope windstorm, this function is assumed to be linear, and the proportionality constant to be negative. However, the possibility of its positiveness can not be excluded. In this note, the case for the constant to be positive is examined, and the followings are shown. Also in this case, there exist solutions representing downslope windstorms. The unnatural upper bound for the atmospheric height in Smith (1985)'s solution does not emerge, and the solution may exist for any large value of the atmospheric height. The ratio of the mountain height to the atmospheric height is somewhat greater than that of Smith (1985)'s solution.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"464 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023334","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}
A brief comparison between the Deutscher Wetterdienst's next generation nonhydrostatic regional forecast model (the Local-Modell of DWD) and the Meteorological Research Institute mesoscale nonhydrostatic model (MRI-NHM) is performed by computing the numerical solutions of the 3-dimensional mountain waves over an isolated circular mountain. For linear cases with a free-slip lower boundary condition, both models well reproduce the characteristics of the Smith's (1980) analytic solutions for the 3-dimensional nonhydrostatic mountain waves. Analysis of the CPU time of the two models with the CRAY C-98 of DWD shows the tendency that the Local-Modell (time-splitting, horizontally explicit model) is relatively efficient in lower horizontal resolution while MRI-NHM (3D-implicit model) becomes more efficient at higher horizontal resolution. This is because the number of small time step integrations of the horizontally explicit model increases when the horizontal resolution becomes higher. The CPU time for one iterative procedure in the direct method for the three dimensional elliptic pressure equation in MRI-NHM is 2.1∼2.6 times of that for one small time step integration in the Lokal-Modell. A rough yardstick which determines the comparative efficiency of the two models is given by the relative magnitude between the Courant-number for sound wave speed and the number of iterative procedures in the elliptic pressure equation solver in the 3D implicit model.
通过计算孤立圆形山上三维山波的数值解，对Deutscher weterdienst的新一代非流体静力区域预报模式(local - model of DWD)和气象研究所的中尺度非流体静力模式(MRI-NHM)进行了简要比较。对于具有自由滑移下边界条件的线性情况，两个模型都很好地再现了三维非静力山波的Smith(1980)解析解的特征。用DWD的CRAY C-98对两种模型的CPU时间进行分析，发现local - model(时间分裂、水平显式模型)在较低水平分辨率下效率相对较高，而MRI-NHM (3d隐式模型)在较高水平分辨率下效率更高。这是因为水平显式模型的小时间步长积分次数随着水平分辨率的提高而增加。MRI-NHM中三维椭圆压力方程的直接法一次迭代过程的CPU时间是local - model中一次小时间步积分的2.1 ~ 2.6倍。在三维隐式模型中，声速柯朗数与椭圆压力方程求解器的迭代次数之间的相对大小，给出了两种模型比较效率的粗略尺度。
{"title":"3-D Mountain Waves by the Lokal-Modell of DWD and the MRI Mesoscale Nonhydrostatic Model.","authors":"Kazuo Saito, G. Doms, U. Schaettler, J. Steppeler","doi":"10.2467/MRIPAPERS.49.7","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.49.7","url":null,"abstract":"A brief comparison between the Deutscher Wetterdienst's next generation nonhydrostatic regional forecast model (the Local-Modell of DWD) and the Meteorological Research Institute mesoscale nonhydrostatic model (MRI-NHM) is performed by computing the numerical solutions of the 3-dimensional mountain waves over an isolated circular mountain. For linear cases with a free-slip lower boundary condition, both models well reproduce the characteristics of the Smith's (1980) analytic solutions for the 3-dimensional nonhydrostatic mountain waves. Analysis of the CPU time of the two models with the CRAY C-98 of DWD shows the tendency that the Local-Modell (time-splitting, horizontally explicit model) is relatively efficient in lower horizontal resolution while MRI-NHM (3D-implicit model) becomes more efficient at higher horizontal resolution. This is because the number of small time step integrations of the horizontally explicit model increases when the horizontal resolution becomes higher. The CPU time for one iterative procedure in the direct method for the three dimensional elliptic pressure equation in MRI-NHM is 2.1∼2.6 times of that for one small time step integration in the Lokal-Modell. A rough yardstick which determines the comparative efficiency of the two models is given by the relative magnitude between the Courant-number for sound wave speed and the number of iterative procedures in the elliptic pressure equation solver in the 3D implicit model.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"49 1","pages":"7-19"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023553","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}
Wehave done several three−dimensional numerical stomsurge simulationsusingtheterrain− following Princeton oceanmode1（POM）withhorizontallyuniformstratification inthe area ofTosa Bay（maximum depth二4，800m）．Results show slightly larger peak surges wi蜘finer vertical resolution or stronger stratification．We report the effects of the vertical mixing fom on the SimUlated Sea leVel． The balance of forces in momentum equations are studied in some detaiL A simple explanation is proposed as to expla圭n why larger peak surges are found as vertical resolution becomes finer．
{"title":"Storm Surge Simulation using POM and a Revisitation of Dynamics of Sea Surface Elevation Short-Term Variation.","authors":"Shinya Minato","doi":"10.2467/MRIPAPERS.48.79","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.48.79","url":null,"abstract":"Wehave done several three−dimensional numerical stomsurge simulationsusingtheterrain− following Princeton oceanmode1（POM）withhorizontallyuniformstratification inthe area ofTosa Bay（maximum depth二4，800m）．Results show slightly larger peak surges wi蜘finer vertical resolution or stronger stratification．We report the effects of the vertical mixing fom on the SimUlated Sea leVel． The balance of forces in momentum equations are studied in some detaiL A simple explanation is proposed as to expla圭n why larger peak surges are found as vertical resolution becomes finer．","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"48 1","pages":"79-88"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2467/MRIPAPERS.48.79","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023269","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":"Crustal deformation due to a pressure source with directivity.","authors":"T. Tsukakoshi, T. Odaka","doi":"10.2467/MRIPAPERS.48.101","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.48.101","url":null,"abstract":"近年の伊豆半島における地殻の上下変動の図を参照すると、(1) 隆起の中心が移動すること、(2) 目玉状の振幅の大きな隆起域に隣接して小振幅の沈降域があること、など幾つか特徴的な現象が見受けられる。 本研究では、指向性を有する圧力源モデルを新たに導入して、三次元有限要素法による数値解析等を行い、これらの地殻変動現象がこのモデル、あるいは球状均等圧力源モデルによって定性的に説明可能であるかの考察を行った。 その結果、(1) については複数の分布した均等圧力源あるいは指向性圧力源により説明可能である。(2) についても同様である。しかし、均等圧力源モデルでは沈降域の目玉の真下に圧力源 (減圧) が存在しなければならないが、ある特定の期間に典型的に見られた上下変動パターンの場合、沈降域の目玉の付近に圧力源となる火山などは分布せず、均等圧力源では説明困難であり、指向性圧力源で説明できる可能性があることがわかった。その他、指向性圧力源は、開口断層に比べて、隆起域に隣接して生じる沈降域をより効率的に生じ得ることを示した。 また、球状均等圧力源モデルに対して計算を行い、本稿で用いた数値解法の妥当性を確認するとともに、低速度表層の存在がそれの無い場合に比べて水平変位を1.3倍程増大させることなどを示した。","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"48 1","pages":"101-113"},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023505","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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