K. Shibata, M. Deushi, T. Sekiyama, Hiromasa Yoshimura
A three-dimensional chemical transport model(CTM) was developed at the Meteorological Research Institute by coupling a chemical module with the MJ98 general circulation model (dynamical module) for the study of stratospheric chemistry.This model, MJ98-CTM, ran for approximately 15 years and the simulated chemical species were investigated, focusing on the time-mean fields. The chemical module was based on the family method and contains major stratospheric species, i.e., 34 long-lived species including 7 families and 15 short-lived species with 79 gas phase reactions and 34 photodissociations. Two types (I and II) of polar stratospheric clouds (PSCs) and sulfate aerosols were included with six heterogeneous reactions on PSCs and three heterogeneous reactions on sulfate aerosols. MJ98-CTMs of T21L45 and T42L45 versions were integrated using climatological monthly mean values of sea-surface temperature and ozone for the dynamical module, and fixed values at the surface for surface-origin species in the chemical module. Radiatively active gases such as ozone, methane, and nitrous oxide were not treated interactively between the two modules. Horizontal resolutions were 5.6°(∼600 km) for the T21 model and 2.8°(∼300 km) for the T42 model. The vertical resolution L45 had a vertical spacing of about 2 km in the stratosphere with a top at 0.01 hPa (80km). Qualitatively, MJ98-CTM suitably reproduced the temporal and spatial features of observed ozone and other chemical species in the middle atmosphere. However, the lower stratosphere held crucial errors for the distributions of chemical species, particularly ozone, yielding positive errors for column ozone. A major cause of these errors can be ascribed to the errors associated with transport: one based on the wind field bias produced by MJ98, and the other from the coarse vertical resolution.
{"title":"Development of an MRI Chemical Transport Model for the Study of Stratospheric Chemistry","authors":"K. Shibata, M. Deushi, T. Sekiyama, Hiromasa Yoshimura","doi":"10.2467/MRIPAPERS.55.75","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.55.75","url":null,"abstract":"A three-dimensional chemical transport model(CTM) was developed at the Meteorological Research Institute by coupling a chemical module with the MJ98 general circulation model (dynamical module) for the study of stratospheric chemistry.This model, MJ98-CTM, ran for approximately 15 years and the simulated chemical species were investigated, focusing on the time-mean fields. The chemical module was based on the family method and contains major stratospheric species, i.e., 34 long-lived species including 7 families and 15 short-lived species with 79 gas phase reactions and 34 photodissociations. Two types (I and II) of polar stratospheric clouds (PSCs) and sulfate aerosols were included with six heterogeneous reactions on PSCs and three heterogeneous reactions on sulfate aerosols. MJ98-CTMs of T21L45 and T42L45 versions were integrated using climatological monthly mean values of sea-surface temperature and ozone for the dynamical module, and fixed values at the surface for surface-origin species in the chemical module. Radiatively active gases such as ozone, methane, and nitrous oxide were not treated interactively between the two modules. Horizontal resolutions were 5.6°(∼600 km) for the T21 model and 2.8°(∼300 km) for the T42 model. The vertical resolution L45 had a vertical spacing of about 2 km in the stratosphere with a top at 0.01 hPa (80km). Qualitatively, MJ98-CTM suitably reproduced the temporal and spatial features of observed ozone and other chemical species in the middle atmosphere. However, the lower stratosphere held crucial errors for the distributions of chemical species, particularly ozone, yielding positive errors for column ozone. A major cause of these errors can be ascribed to the errors associated with transport: one based on the wind field bias produced by MJ98, and the other from the coarse vertical resolution.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"55 1","pages":"75-119"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69025048","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. Matsueda, Y. Sawa, A. Wada, H. Inoue, K. Suda, Yoshiaki Hirano, K. Tsuboi, S. Nishioka
A calibration system of standard gases for atmospheric methane measurements using a gas chromatograph equipped with a flame ionization detector was developed at the Meteorological Research Institute (MRI) in 1993 and later at the Japan Meteorological Agency (JMA) in 2000. Calibration results for the two systems exhibited good agreement. Although the primary standard gases of the MRI and JMA were prepared independently using the gravimetric method, their methane standard scales were quite similar, (a difference of less than 1 ppb). A comparison of gravimetric standards prepared by several Japanese gas companies showed a methane scale difference within ∼5 ppb relative to the primary standards of the MRI. These gravimetric-scale differences were primarily caused by methane impurities in the diluent air used for standard gas preparation. Long-term storage experiments indicated that the methane contents of standard gases were stable in high-pressure cylinders for 8-9 years. No significant drift of methane was found in any of the standard gases in the MRI; however, to evaluate the stability of the JMA standards, data collected over a longer period of time is required. We evaluated the differences between the methane scales of the MRI and other laboratories based on the previous intercomparison experiments. The differences found in the standard scales used by different laboratories were largely due to the diverse origins of the primary standard gases.
{"title":"Methane standard gases for atmospheric measurements at the MRI and JMA and intercomparison experiments","authors":"H. Matsueda, Y. Sawa, A. Wada, H. Inoue, K. Suda, Yoshiaki Hirano, K. Tsuboi, S. Nishioka","doi":"10.2467/MRIPAPERS.54.91","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.54.91","url":null,"abstract":"A calibration system of standard gases for atmospheric methane measurements using a gas chromatograph equipped with a flame ionization detector was developed at the Meteorological Research Institute (MRI) in 1993 and later at the Japan Meteorological Agency (JMA) in 2000. Calibration results for the two systems exhibited good agreement. Although the primary standard gases of the MRI and JMA were prepared independently using the gravimetric method, their methane standard scales were quite similar, (a difference of less than 1 ppb). A comparison of gravimetric standards prepared by several Japanese gas companies showed a methane scale difference within ∼5 ppb relative to the primary standards of the MRI. These gravimetric-scale differences were primarily caused by methane impurities in the diluent air used for standard gas preparation. Long-term storage experiments indicated that the methane contents of standard gases were stable in high-pressure cylinders for 8-9 years. No significant drift of methane was found in any of the standard gases in the MRI; however, to evaluate the stability of the JMA standards, data collected over a longer period of time is required. We evaluated the differences between the methane scales of the MRI and other laboratories based on the previous intercomparison experiments. The differences found in the standard scales used by different laboratories were largely due to the diverse origins of the primary standard gases.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"54 1","pages":"91-109"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024823","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. Noda, M. Sugi, Y. Kitamura, M. Hosaka, K. Shibata, S. Maeda
{"title":"The New Meteorological Research Institute Coupled GCM ( MRI-CGCM 2 )---Model Climate and Variability","authors":"A. Noda, M. Sugi, Y. Kitamura, M. Hosaka, K. Shibata, S. Maeda","doi":"10.2467/mripapers.51.47","DOIUrl":"https://doi.org/10.2467/mripapers.51.47","url":null,"abstract":"","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2467/mripapers.51.47","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69023910","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 : 2004-01-01DOI: 10.2467/MRIPAPERS.54.111
K. Kodera, Kazutaka Yamada
{"title":"Impact of the SH major stratospheric warming on the Hadley circulation : A case study","authors":"K. Kodera, Kazutaka Yamada","doi":"10.2467/MRIPAPERS.54.111","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.54.111","url":null,"abstract":"","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"54 1","pages":"111-116"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024719","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}
We examined two techniques for eliminating components induced by variations of the geomagnetic field to accurately and quickly detect anomalous changes in the geoelectric field, which would enable us to identify crustal signals,. One method is based on a multiple regression model, where any geoelectric variation is presented as a linear combination of the past, present, and future values of geomagnetic variations. The induced geoelectric variation is estimated as a convolution of the geomagnetic variations and the parameters of the obtained regression model. The other method uses BAYTAP-G, by which the observed geoelectric data are separated into four components: 1) tidal, 2) electromagnetically induced, 3) trend, and 4) irregular components. Signals due to volcanic and/or seismic activity may be detected since the trend and the irregular component indicate variations of the self-potential of the crust and/or noise, provided that the amplitudes exceed that of the typical variation. The geomagnetic field at the Kakioka Magnetic Observatory was used as associated data for both methods. These methods were applied to geoelectric variations in the Numazu group, which are contaminated by artificial noise but show anomalous changes. The multiple regression method can apparently eliminate daily variations and telluric storms and can clarify anomalous changes that are not obvious in the original data. However, the gain and phase characteristics calculated from the estimated parameters of the model do not yield information on the underground resistivity structure since the estimated impulse responses do not correctly reflect relationships between the inducing geomagnetic field and the induced geoelectric field due to the presence of excessive artificial noise. BAYTAP-G separates daily variations due to artificial noise as the tidal component and the responses to geomagnetic variations. Anomalous changes are identified in the trend and the irregular component.We investigated the relationship of the tidal component of geoelectric variations estimated by BAYTAP-G with the tidal current and the tide. The correlation between the tidal component of geoelectric variations and tidal currents could not be clarified since simultaneous data of tidal currents with geoelectric variations were not available. Temporal variations of the amplitudes of geoelectric variations of KSM-MTO and tides at OAR for O1 and M2 constituents were not correlated despite their high coherencies.
{"title":"Application of statistical models to geoelectric variations with a long electrode span to detect anomalous changes","authors":"H. Takayama","doi":"10.2467/MRIPAPERS.54.1","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.54.1","url":null,"abstract":"We examined two techniques for eliminating components induced by variations of the geomagnetic field to accurately and quickly detect anomalous changes in the geoelectric field, which would enable us to identify crustal signals,. One method is based on a multiple regression model, where any geoelectric variation is presented as a linear combination of the past, present, and future values of geomagnetic variations. The induced geoelectric variation is estimated as a convolution of the geomagnetic variations and the parameters of the obtained regression model. The other method uses BAYTAP-G, by which the observed geoelectric data are separated into four components: 1) tidal, 2) electromagnetically induced, 3) trend, and 4) irregular components. Signals due to volcanic and/or seismic activity may be detected since the trend and the irregular component indicate variations of the self-potential of the crust and/or noise, provided that the amplitudes exceed that of the typical variation. The geomagnetic field at the Kakioka Magnetic Observatory was used as associated data for both methods. These methods were applied to geoelectric variations in the Numazu group, which are contaminated by artificial noise but show anomalous changes. The multiple regression method can apparently eliminate daily variations and telluric storms and can clarify anomalous changes that are not obvious in the original data. However, the gain and phase characteristics calculated from the estimated parameters of the model do not yield information on the underground resistivity structure since the estimated impulse responses do not correctly reflect relationships between the inducing geomagnetic field and the induced geoelectric field due to the presence of excessive artificial noise. BAYTAP-G separates daily variations due to artificial noise as the tidal component and the responses to geomagnetic variations. Anomalous changes are identified in the trend and the irregular component.We investigated the relationship of the tidal component of geoelectric variations estimated by BAYTAP-G with the tidal current and the tide. The correlation between the tidal component of geoelectric variations and tidal currents could not be clarified since simultaneous data of tidal currents with geoelectric variations were not available. Temporal variations of the amplitudes of geoelectric variations of KSM-MTO and tides at OAR for O1 and M2 constituents were not correlated despite their high coherencies.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"54 1","pages":"1-45"},"PeriodicalIF":0.0,"publicationDate":"2003-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024694","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}
We propose a time-domain method for estimating the apparent resistivity and phase. The method utilizes a multiple regression model where the order is determined by minimizing the AIC (Akaike Information Criterion). The method is superior to conventional frequency-domain methods based on spectral analysis, since the data length necessary for the latter methods is several times longer than that for the former in estimating the apparent resistivity at the same low frequency. Therefore, applying this method to shorter length data having long wavelengths like those in a magnetic storm, we can estimate apparent resistivities and phases at low frequencies with little effect of the finite wavelength of the inducing geomagnetic field. This method was applied to geoelectric field data observed by means of telegraphic facilities and geomagnetic field data at the Kakioka Magnetic Observatory, which is the standard observatory in Japan, located in the observation network of the geoelectric field. The geoelectric field data are very stable over a long time period because the electrodes are buried to a depth of more than 5 meters and have a contact resistance of less than 2 ohms. Furthermore, the geoelectric data had a high signal-to-noise ratio (signal is induced variations), because the lengths of observation lines ranging from 18.8 to 27.4 km were much longer than that of ordinary observations and the greater part of geoelectric variations were induced by geomagnetic variations. Apparent resistivity and phase in the low-frequency range from 3.3 × 10-5 to 10 × 1.0-3 Hz (corresponding to periods of 512 to 16 minutes) were estimated. Since the time span of the data used in the analysis was within the period of a large-scale magnetic storm, the estimates were unlikely to be affected by the finite wavelength of the inducing geomagnetic field.
{"title":"Estimating apparent resistivity and phase at low frequencies using telegraphic facilities","authors":"H. Takayama","doi":"10.2467/MRIPAPERS.54.47","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.54.47","url":null,"abstract":"We propose a time-domain method for estimating the apparent resistivity and phase. The method utilizes a multiple regression model where the order is determined by minimizing the AIC (Akaike Information Criterion). The method is superior to conventional frequency-domain methods based on spectral analysis, since the data length necessary for the latter methods is several times longer than that for the former in estimating the apparent resistivity at the same low frequency. Therefore, applying this method to shorter length data having long wavelengths like those in a magnetic storm, we can estimate apparent resistivities and phases at low frequencies with little effect of the finite wavelength of the inducing geomagnetic field. This method was applied to geoelectric field data observed by means of telegraphic facilities and geomagnetic field data at the Kakioka Magnetic Observatory, which is the standard observatory in Japan, located in the observation network of the geoelectric field. The geoelectric field data are very stable over a long time period because the electrodes are buried to a depth of more than 5 meters and have a contact resistance of less than 2 ohms. Furthermore, the geoelectric data had a high signal-to-noise ratio (signal is induced variations), because the lengths of observation lines ranging from 18.8 to 27.4 km were much longer than that of ordinary observations and the greater part of geoelectric variations were induced by geomagnetic variations. Apparent resistivity and phase in the low-frequency range from 3.3 × 10-5 to 10 × 1.0-3 Hz (corresponding to periods of 512 to 16 minutes) were estimated. Since the time span of the data used in the analysis was within the period of a large-scale magnetic storm, the estimates were unlikely to be affected by the finite wavelength of the inducing geomagnetic field.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"54 1","pages":"47-58"},"PeriodicalIF":0.0,"publicationDate":"2003-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024759","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 : 2003-03-31DOI: 10.2467/MRIPAPERS.53.109
K. Hirose, 勝己 廣瀬
234Th has been widely applied as a tracer of particulate organic carbon (POC) fluxes in the upper ocean. Fundamental to this approach is the determination of 234Th fluxes from water column measurements of the 234Th-238U disequilibria, and the conversion of 234Th flux to POC export, using the measured POC/234Th ratio on particles. As such, POC/234Th ratios are one of the most critical factors in quantifying the carbon export flux in ocean interior when using this approach. However, the POC/234Th ratios show significant temporal and spatial variations, but cannot be predicted at this time. Therefore, it is important to elucidate factors controlling the variations of the POC/234Th ratios. To achieve this purpose, we should understand the chemical interactions between POC and 234Th. In the open ocean, POC/234Th ratios have been determined together with other oceanographic parameters. We examined here the relationship between POC/234Th and primary production. The POC/234Th ratios were linearly related to logarithmic values of primary production. Taken into account the complexation between surface ligand on particulate organic matter (POM) and 234Th, a complexation model suggests that the size of particles adsorbing 234Th is related to primary production; in the equatorial Pacific, the size of particles adsorbing 234Th apparently decreases with increasing primary production, whereas opposite phenomenon occurs in the North Atlantic. Since the POC/234Th ratios were determined in filtered particulate matter, this finding suggests that aggregation of small particles would be dominant in the equatorial Pacific, which can be explained by a chemical aggregation model.
{"title":"Implication of POC/T[lc]h-234 ratios in oceanic particulate matter: An approach to particle aggregation","authors":"K. Hirose, 勝己 廣瀬","doi":"10.2467/MRIPAPERS.53.109","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.53.109","url":null,"abstract":"234Th has been widely applied as a tracer of particulate organic carbon (POC) fluxes in the upper ocean. Fundamental to this approach is the determination of 234Th fluxes from water column measurements of the 234Th-238U disequilibria, and the conversion of 234Th flux to POC export, using the measured POC/234Th ratio on particles. As such, POC/234Th ratios are one of the most critical factors in quantifying the carbon export flux in ocean interior when using this approach. However, the POC/234Th ratios show significant temporal and spatial variations, but cannot be predicted at this time. Therefore, it is important to elucidate factors controlling the variations of the POC/234Th ratios. To achieve this purpose, we should understand the chemical interactions between POC and 234Th. In the open ocean, POC/234Th ratios have been determined together with other oceanographic parameters. We examined here the relationship between POC/234Th and primary production. The POC/234Th ratios were linearly related to logarithmic values of primary production. Taken into account the complexation between surface ligand on particulate organic matter (POM) and 234Th, a complexation model suggests that the size of particles adsorbing 234Th is related to primary production; in the equatorial Pacific, the size of particles adsorbing 234Th apparently decreases with increasing primary production, whereas opposite phenomenon occurs in the North Atlantic. Since the POC/234Th ratios were determined in filtered particulate matter, this finding suggests that aggregation of small particles would be dominant in the equatorial Pacific, which can be explained by a chemical aggregation model.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"53 1","pages":"109-118"},"PeriodicalIF":0.0,"publicationDate":"2003-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024351","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 : 2003-03-31DOI: 10.2467/mripapers.53.119
Y. Tanaka, Kotaro Orito, T. Sekiyama, K. Shibata, M. Chiba, Hiroshi L. Tanaka, 泰宙 田中, 折戸 光太郎, 剛 関山, 清孝 柴田, 長 千葉, 浩 田中
{"title":"MASINGAR, a global tropospheric aerosol chemical transport model coupled with MRI/JMA98 GCM: Model description","authors":"Y. Tanaka, Kotaro Orito, T. Sekiyama, K. Shibata, M. Chiba, Hiroshi L. Tanaka, 泰宙 田中, 折戸 光太郎, 剛 関山, 清孝 柴田, 長 千葉, 浩 田中","doi":"10.2467/mripapers.53.119","DOIUrl":"https://doi.org/10.2467/mripapers.53.119","url":null,"abstract":"","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"53 1","pages":"119-138"},"PeriodicalIF":0.0,"publicationDate":"2003-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024397","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}
Some tropical cyclones in the western North Pacific have particular characteristics, classified as the SH pattern by the Japan Meteorological Agency (1990). One such cyclone, Tropical Storm Bolaven (0006), which took an irregular track in the East China Sea in midsummer, was examined. It did not attain typhoon intensity, and had associated deep convective clouds only in the south and dry air in the middle and upper troposphere in the north of the cyclone. The northern dry region was warmer than the southern moist region, and therefore the cyclone was associated with baroclinicity in the middle troposphere. However, the surface wind field was similar to that of a typical tropical cyclone. We also examined the relation of the structure of Bolaven and its environment using the objective analysis dataset of JMA. Bolaven was located southeast of a prominent Tibetan high in the early stage of its lifecycle. In the upper troposphere, a strong northerly wind on the eastern fringe of the Tibetan high converged in the north of Bolaven, and an easterly flow diverged in the south of Bolaven. It is inferred that regional differences in the curvature of the geopotential height field associated with the Tibetan high and the cyclone, and the consequent inertial stability, contributed to the flow and the distribution of horizontal divergence. In the middle troposphere, zonal temperature gradients were generated by the warm continental air mass in the western North Pacific, where the circulation of Bolaven generated horizontal temperature advection. These contributed to the asymmetric distribution of the vertical motion near the cyclone and to the irregular movement of the cyclone. In the later stage of its lifecycle, Bolaven had the structure of a meridionally reversed baroclinic disturbance in the middle troposphere, although the large-scale environment changed significantly in the upper troposphere. This suggests that an asymmetric tropical cyclone organized in a particular environment could be maintained by midtropospheric frontogenesis through the tilting effect for some period.
{"title":"Structure of an Atypical Midsummer Tropical Cyclone in the East China Sea and the Environmental Effects on It.","authors":"北畠 尚子","doi":"10.2467/MRIPAPERS.53.59","DOIUrl":"https://doi.org/10.2467/MRIPAPERS.53.59","url":null,"abstract":"Some tropical cyclones in the western North Pacific have particular characteristics, classified as the SH pattern by the Japan Meteorological Agency (1990). One such cyclone, Tropical Storm Bolaven (0006), which took an irregular track in the East China Sea in midsummer, was examined. It did not attain typhoon intensity, and had associated deep convective clouds only in the south and dry air in the middle and upper troposphere in the north of the cyclone. The northern dry region was warmer than the southern moist region, and therefore the cyclone was associated with baroclinicity in the middle troposphere. However, the surface wind field was similar to that of a typical tropical cyclone. We also examined the relation of the structure of Bolaven and its environment using the objective analysis dataset of JMA. Bolaven was located southeast of a prominent Tibetan high in the early stage of its lifecycle. In the upper troposphere, a strong northerly wind on the eastern fringe of the Tibetan high converged in the north of Bolaven, and an easterly flow diverged in the south of Bolaven. It is inferred that regional differences in the curvature of the geopotential height field associated with the Tibetan high and the cyclone, and the consequent inertial stability, contributed to the flow and the distribution of horizontal divergence. In the middle troposphere, zonal temperature gradients were generated by the warm continental air mass in the western North Pacific, where the circulation of Bolaven generated horizontal temperature advection. These contributed to the asymmetric distribution of the vertical motion near the cyclone and to the irregular movement of the cyclone. In the later stage of its lifecycle, Bolaven had the structure of a meridionally reversed baroclinic disturbance in the middle troposphere, although the large-scale environment changed significantly in the upper troposphere. This suggests that an asymmetric tropical cyclone organized in a particular environment could be maintained by midtropospheric frontogenesis through the tilting effect for some period.","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"53 1","pages":"59-73"},"PeriodicalIF":0.0,"publicationDate":"2002-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024463","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":"Fabricating Thermocouple Micro Psychrometers by the Bonding-Cellulose Method.","authors":"Nobuyuki Kinoshita","doi":"10.2467/mripapers.53.85","DOIUrl":"https://doi.org/10.2467/mripapers.53.85","url":null,"abstract":"","PeriodicalId":39821,"journal":{"name":"Papers in Meteorology and Geophysics","volume":"40 1","pages":"85-90"},"PeriodicalIF":0.0,"publicationDate":"2002-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69024536","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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