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21.
Fog and rain water chemistry at Mt. Fuji: A case study during the September 2002 campaign 总被引:2,自引:0,他引:2
Koichi Watanabe Yusaku Takebe Nobuhiro Sode Yasuhito Igarashi Hiroshi Takahashi Yukiko Dokiya 《Atmospheric Research》2006,82(3-4):652
Measurements of fog and rain water chemistry at the summit of Mt. Fuji, the highest peak in Japan, as well as at Tarobo, the ESE slope of Mt. Fuji in September 2002. The pH of fog and rain water sampled at Mt. Fuji varied over a range of 4.0–6.8. Acidic fogs (pH < 5.0) were observed at the summit when the air mass came from the industrial regions on the Asian continent. The ratio of [SO42−]/[NO3−] in the fog water was lower at Tarobo than at the summit. High concentrations of Na+ and Cl− were determined in the rain water sampled at the summit, possibly because of the long-range transport of sea-salt particles raised by a typhoon through the middle troposphere. The vertical transport of sea-salt particles would influence the cloud microphysical properties in the middle troposphere. Significant loss of Mg2+ was seen in the rain water at the summit. The concentrations of peroxides in the fog and rain water were relatively large (10–105 μM). The potential capacity for SO2 oxidation seems to be strong from summer to early autumn at Mt. Fuji. The fog water peroxide concentrations displayed diurnal variability. The peroxide concentrations in the nighttime were significantly higher than those in the daytime. 相似文献
22.
Wataru Ootani Makoto Minowa Takayuki Watanabe Yutaka Ito Yasuhiro Kishimoto Kentaro Miuchi Yoshizumi Inoue Youiti Ootuka 《Astroparticle Physics》1998,9(4):325-329
The performance of a 21-g lithium fluoride bolometer is presented. The background spectrum was measured in the surface laboratory. We derive an exclusion plot for the spin-dependent coupled Weakly Interacting Massive Particles (WIMPs) cross section. 相似文献
23.
An investigation to systematize empirical equations for the shear wave velocity of soils was made in terms of four characteristic indexes. The adopted indexes are the N-value of the Standard Penetration Test, depth where the soil is situated, geological epoch and soil type. As some of these indexes are variates belonging to interval scales while others belong to nominal or ordinal scales, the technique known as a multivariate analysis cannot be employed. A new approach to the theory of quantification, after C. Hayashi, was introduced and developed for solving this difficulty. Fifteen sets of empirical equations to estimate low strain shear wave velocity theoretically may be obtained by combining the above four indexes. All of these sets were derived by use of about 300 data, and their accuracies were evaluated by means of correlation coefficients between the measured and estimated shear wave velocities. The best equation was found to be the one which included all the indexes, and its correlation coefficient was 0.86. The empirical equation relating the standard penetration N-value to the shear wave velocity provided a correlation of only 0.72, and is one of the lowest ranking among the 15 sets of equations. 相似文献
24.
Partitioning of Ni2+, Co2+, Fe2+, Mn2+ and Mg2+ between olivine and silicate melts: compositional dependence of partition coefficient 总被引:1,自引:0,他引:1
Eiichi Takahashi 《Geochimica et cosmochimica acta》1978,42(12):1829-1844
Partitioning of Ni2+, Co2+, Fe2+, Mn2+ and Mg2+ between olivine and silicate melts has been determined near the join (Mg0.5·-Fe0.5)2SiO4-K2O 4SiO2 and for seven different basaltic compositions. The experiments were made at 1 atm total pressure, 1500-1100°C, and under moderate to reducing oxygen fugacities. The concentration factor, defined as KMO = (MO)ol/(MO)liq (molar ratio), increases markedly for all the cations studied as the olivine component of the liquid decreases. Much of the increase in KMO is considered as due to the compositional effect of the coexisting liquid: the temperature effect on KMO is probably opposite to the compositional effect (KMO decreases as temperature decreases).The partition coefficient KMO-MgO = (MO/MgO)ol/(MO/MgO)liq for the reaction, Mol2+ + Mgliq2+ = Mliq2+ + Mgol2+. is relatively constant over a wide range of SiO2 content of the liquid, except in the case of Ni2+. The partition coefficients have similar ranges both in synthetic and natural rock systems: KNiO-MgO = 1.8–3.0, KCoO-MgO = 0.6–0.8, KFeO-MgO = 0.27–0.38, and KMnO-MgO = 0.23–0.32. There is a systematic variation in the partition coefficient KMO-MgO with the composition of liquid; KMO-MgO increases with increasing SiO2 content of melt. The partition coefficients for Co2+, Fe2+ and Mn2+ are useful to test the equilibration of olivine with magma of a wide compositional range. 相似文献
25.
Masayuki Takahashi Isao Koike Takashi Ishimaru Toshiro Saino Ken Furuya Yoshihiko Fujita Akihiko Hattori Shun-ei Ichimura 《Journal of Oceanography》1980,36(4):209-216
Water plumes, 20 km long or less, identified by low temperature, high salinity and high nutrient concentrations, were observed on the eastern side of Izu Islands where the Kuroshio Current or its branch flowed eastward. The T-S diagrams and the vertical profiles of oceanographic variables indicated that the water plumes resulted from the upwelling of subsurface water. A newly formed plume, characterized by a sharp temperature front and high nutrient concentrations, contained less chlorophyll than did old plumes. It is suggested that the upwelling plumes are maintained for a period long enough to allow luxuriant growth of phytoplankton. 相似文献
26.
27.
与季节内振荡-超级云团系统相关的赤道波的识别 总被引:2,自引:0,他引:2
文中重点研究与热带季节内振荡-超级云团系统相关联的赤道波的识别。考虑到赤道波的本质为截获在赤道地区的一般的气候平衡场附近的线性动力过程的固有模态,首先从原理上阐明了POPs分析技术对于分离各类赤道波动的有效性,以后利用这种分析方法对日本静止气象卫星所观测到的黑体红外辐射温度资料进行了POPs分析。结果表明,在热带季节内振荡-超级云团系统中,对应于40d振荡的模态基本表现为Kelvin波的结构;对应于10d左右的模态,亦为Kelvin波,而在2d尺度上,则分别存在经向模态序号n=1和n=2的西进和东进惯性重力波。分析中还发现了西进的混合Rossby重力波的存在。 相似文献
28.
It is widely recognized that the use of Froude similarity for scaling up wave impact pressures recorded during physical model tests may lead to over-estimation of impact maxima. Based on reviewing historical work dating back to the 30s and further developments in the 60s and 80s, a general method is presented that is suitable for scaling up impact pressures and rise times measured during small scale physical model tests. The method accounts for the effect of air leakage and is applicable to most wave impact loads. The model is applied to scale wave impact pressures on vertical walls and similar structures, and consistent correction factors for the Froude scaling law are derived. 相似文献
29.
Seasonal variability regarding the nature of precipitation and the activity of cumulus convection during the 1991 Meiyu season of Changjiang-Huaihe River Basin(Jianghuai)has been investigated by calculating apparent heat source/apparent moisture sink and analyzing TBB(cloud-top blackody radiation temperature)data.It is found that three periods of strong ascending motion during the Meiyu season lead to three episodes of heavy rain,and the latent heat due to the precipitation is of the sole heat source of the atmosphere.The nature of precipitation shows distinct seasonal variability,from frontal precipitation of the first episode to the extremely strong convective precipitation of the third episode.TBB field of East Asia may well reflect not only the intensity of convection and rainfall,but also the movement of rain belt and convection belt.In the whole Meiyu season.convection belt mainly stays in Jianghuai.but may shift within the domain of East Asia.Its locating in Jianghuai or not determines the maintenance or break of Meiyu.In the third episode,the narrow convection belt over Jianghuai is mainly caused by southwest monsoon which takes moist and convective atmosphere from tropical ocean. 相似文献
30.
Ayaka Sakabe Ken Hamotani Yoshiko Kosugi Masahito Ueyama Kenshi Takahashi Akito Kanazawa Masayuki Itoh 《Theoretical and Applied Climatology》2012,109(1-2):39-49
Very few studies have conducted long-term observations of methane (CH4) flux over forest canopies. In this study, we continuously measured CH4 fluxes over an evergreen coniferous (Japanese cypress) forest canopy throughout 1?year, using a micrometeorological relaxed eddy accumulation (REA) system with tuneable diode laser spectroscopy (TDLS) detection. The Japanese cypress forest, which is a common forest type in warm-temperate Asian monsoon regions with a wet summer, switched seasonally between a sink and source of CH4 probably because of competition by methanogens and methanotrophs, which are both influenced by soil conditions (e.g., soil temperature and soil moisture). At hourly to daily timescales, the CH4 fluxes were sensitive to rainfall, probably because CH4 emission increased and/or absorption decreased during and after rainfall. The observed canopy-scale fluxes showed complex behaviours beyond those expected from previous plot-scale measurements and the CH4 fluxes changed from sink to source and vice versa. 相似文献