Simulating the carbon balance of a temperate larch forest under various meteorological conditions     

Motomu Toda  Masayuki Yokozawa  Akihiro Sumida  Tsutomu Watanabe  Toshihiko Hara 《Carbon balance and management》2007,2(1):1-18

This editorial provides a subject index from published articles, active researchers, and published papers in the field of carbon balance and management.  相似文献   

End wall effects in experiments on water intrusion along the interface between two homogeneous layers     

Izumi Toda  Yutaka Nagata 《Journal of Oceanography》1980,36(1):15-22

End wall effect puts an inherent limitation on tank experiments, especially when the problems in a stratified fluid are dealt with. During experiments involving horizontal intrusion along the interface between two homogeneous layers, a curious phenomenon was found, i.e., the tip of the intruding water wedge continues to extend for a short time after supply is stopped, but then it begins to retreat in the cases of relatively high Reynolds numbers. The cause of this retreat of the wedge was investigated and was shown to be attributable to the initial disturbance generated near the mouth of the feeder at the start of water supply which propagates along the interface layer and reflects at the end of the tank as a bulge of the interface layer. The retreat of the intruding wedge would not occur in a sufficiently long tank, and so the cause of the retreat can be considered as one kind of end wall effect in a tank.  相似文献   

A fault scarp in an urban area identified by LiDAR survey: A Case study on the Itoigawa–Shizuoka Tectonic Line, central Japan   总被引：2，自引：2，他引：0  

H. Kondo  S. Toda  K. Okumura  K. Takada  T. Chiba 《Geomorphology》2008,101(4):731-739

A light detection and ranging (LiDAR) survey was conducted in a densely built-up area to generate a high-resolution digital elevation model (DEM) to look for active faults. The urban district of Matsumoto City in central Japan is located in a 3-km² basin along the Itoigawa–Shizuoka Tectonic Line active fault system, one of Japanese onshore fault systems with the highest earthquake probability. A high-resolution DEM at a 0.5-m-grid interval was obtained after removing the effects of laser returns from buildings, clouds and vegetation. It revealed a continuous scarp, up to ~ 2 m in height. Borehole data and archaeological studies indicate the scarp was formed during the most recent faulting event associated with historical earthquakes. In addition, the fault scarp strongly supports that the urban district is in a pull-apart basin related to a fault step-over between two left-lateral strike-slip faults. Consequently, accurate interpretation of fault geometry is crucial to provide estimates of future surface deformation and to allow modeling of basin structure and strong ground motion. Thus, the LiDAR mapping survey in urban districts is effective for detailed active fault mapping in order to constrain basin structure and to forecast the exact location of surface rupturing associated with large earthquakes.  相似文献   

Regional-Scale Excess Ar wave in a Barrovian type metamorphic belt, eastern Tibetan Plateau     

Tetsumaru  Itaya  Hironobu  Hyodo  Tatsuki  Tsujimori  Simon  Wallis  Mutsuki  Aoya  Tetsuo  Kawakami  Chitaro  Gouzu 《Island Arc》2009,18(2):293-305

Laser step heating ⁴⁰Ar/³⁹Ar analysis of biotite and muscovite single crystals from a Barrovian type metamorphic belt in the eastern Tibetan plateau yielded consistent cooling ages of ca. 40 Ma in the sillimanite zone with peak metamorphic temperatures higher than 600°C and discordant ages from 46 to 197 Ma in the zones with lower peak temperatures. Chemical Th‐U‐Total Pb Isochron Method (CHIME) monazite (65 Ma) and sensitive high mass‐resolution ion microprobe (SHRIMP) apatite (67 Ma) dating give the age of peak metamorphism in the sillimanite zone. Moderate amounts of excess Ar shown by biotite grains with ages of 46 to 94 Ma at metamorphic grades up to the high‐grade part of the kyanite zone probably represent incomplete degassing during metamorphism. In contrast, the high‐grade part of the kyanite zone yields biotite ages of 130 to 197 Ma. The spatial distribution of these older ages in the kyanite zone along the sillimanite zone boundary suggests they reflect trapped excess argon that migrated from higher‐grade regions. The most likely source is muscovite that decomposed to form sillimanite. The zone with extreme amounts of excess argon preserves trapped remnants of an ‘excess argon wave’. We suggest this corresponds to the area where biotite cooled below its closure temperature in the presence of an elevated Ar wave. Extreme excess Ar is not recognized in muscovite suggesting that the entrapment of the argon wave by biotite took place when the rocks had cooled down to temperatures lower than the closure temperature of muscovite. The breakdown of phengite during ultrahigh‐pressure (UHP) metamorphism may be a key factor in accounting for the very old apparent ages seen in many UHP metamorphic regions. This is the first documentation of a regional Ar‐wave spatially associated with regional metamorphism. This study also implies that resetting of the Ar isotopic systems in micas can require temperatures up to 600°C; much higher than generally thought.  相似文献   

Variability in the Relative Penetration of Ultraviolet Radiation to Photosynthetically Available Radiation in Temperate Coastal Waters, Japan   总被引：1，自引：0，他引：1  

Victor S. Kuwahara  Tatsuki Toda  Koji Hamasaki  Tomohiko Kikuchi  Satoru Taguchi 《Journal of Oceanography》2000,56(4):399-408

UVR and PAR wavelengths are attenuated to different extents within the water column, causing variations in spectral composition with depth. The present investigation (a) describes the variability of UVR and PAR penetration at a station in the temperate coastal waters of Sagami Bay and determines (b) the characteristics of relative UVR penetration to the euphotic zone. Examination of the seasonal irradiance profile measurements indicated eight measurements displaying two distinct attenuation coefficients (K _d) for specific UVR wavelengths and PAR. The two attenuation coefficients observed from specific wavelengths in the water column may be caused not only by chlorophyll pigments, but also by dissolved organic material in the upper layer. The 1% depth of surface UVR at 305, 320, 340, and 380 nm averaged 10.8 ± 5.7, 14.9 ± 9.5, 19.8 ± 12.1, and 30.4 ± 17.6 m, respectively. The depth of euphotic layer displayed less variability averaging 62 ± 15 m throughout the entire study. Relative UVR penetration within the euphotic zone averaged 17.8 ± 8.1, 22.9 ± 10, 30.5 ± 13.8, and 46 ± 46.9% for 305, 320, 340, and 380 nm, respectively. A large variation of the relative transmission of UVR within the euphotic zone was found although the spectral composition was relatively stable in the air throughout the study.  相似文献   

Blueschist-facies metamorphism during Paleozoic orogeny in southwestern Japan: Phengite K–Ar ages of blueschist-facies tectonic blocks in a serpentinite melange beneath early Paleozoic Oeyama ophiolite     

Tatsuki Tsujimori  & Tetsumaru Itaya 《Island Arc》1999,8(2):190-205

Blueschist-bearing Osayama serpentinite melange develops beneath a peridotite body of the Oeyama ophiolite which occupies the highest position structurally in the central Chugoku Mountains. The blueschist-facies tectonic blocks within the serpentinite melange are divided into the lawsonite–pumpellyite grade, lower epidote grade and higher epidote grade by the mineral assemblages of basic schists. The higher epidote-grade block is a garnet–glaucophane schist including eclogite-facies relic minerals and retrogressive lawsonite–pumpellyite-grade minerals. Gabbroic blocks derived from the Oeyama ophiolite are also enclosed as tectonic blocks in the serpentinite matrix and have experienced a blueschist metamorphism together with the other blueschist blocks. The mineralogic and paragenetic features of the Osayama blueschists are compatible with a hypothesis that they were derived from a coherent blueschist-facies metamorphic sequence, formed in a subduction zone with a low geothermal gradient (~ 10°C/km). Phengite K–Ar ages of 16 pelitic and one basic schists yield 289–327 Ma and concentrate around 320 Ma regardless of protolith and metamorphic grade, suggesting quick exhumation of the schists at ca 320 Ma. These petrologic and geochronologic features suggest that the Osayama blueschists comprise a low-grade portion of the Carboniferous Renge metamorphic belt. The Osayama blueschists indicate that the 'cold' subduction type (Franciscan type) metamorphism to reach eclogite-facies and subsequent quick exhumation took place in the northwestern Pacific margin in Carboniferous time, like some other circum-Pacific orogenic belts (western USA and eastern Australia), where such subduction metamorphism already started as early as the Ordovician.  相似文献   

Simultaneous MITSuME g'R_CI_C monitoring of S5 0716+714     

C. S. Stalin  Koji. S. Kawabata  Makoto Uemura  Michitoshi Yoshida  Nobuyuki Kawai  Kenshi Yanagisawa  Yasuhiro Shimizu  Daisuke Kuroda  Shogo Nagayama  Hiroyuki Toda 《Monthly notices of the Royal Astronomical Society》2009,399(3):1357-1366

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Mechanisms of enhanced ocean surface warming in the Kuroshio region for 1951–2010     

Toda  Masaki  Watanabe  Masahiro 《Climate Dynamics》2020,54(9):4129-4145

Climate Dynamics - Since the early twentieth century, observations have shown that the ocean surface has warmed almost globally, but the rate of sea surface temperature (SST) rise in the Kuroshio...  相似文献   

Convergent plate margin processes and their rock record     

John Wakabayashi  Tatsuki Tsujimori  Yujiro Ogawa  John Shervais 《International Geology Review》2015,57(5-8):v-ix

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http://www.sciencedirect.com/science/article/pii/S1674987114000280     

Yoshiaki Ishihara  Masaki Kanao  Masa-yuki Yamamoto  Shigeru Toda  Takeshi Matsushima  Takahiko Murayama 《地学前缘(英文版)》2015,6(2)

Characteristic infrasound waves observed at Antarctic stations demonstrate physical interaction involving environmental changes in the Antarctic continent and the surrounding oceans.A Chaparraltype infrasound sensor was installed at Syowa Station(SYO;39°E,69°S),East Antarctica,as one of the projects of the International Polar Year(IPY2007—2008).Data continuously recorded during the three seasons in 2008—2010 clearly indicate a contamination of the background oceanic signals(microbaroms)with peaks between 4 and 10 s observed during a whole season.The peak amplitudes of the microbaroms have relatively lower values during austral winters,caused by a larger amount of sea-ice extending around the L(u|")tzow-Holm Bay near SYO,with decreasing ocean wave loading effects.Microbaroms measurements are useful tool for characterizing ocean wave climate,complementing other oceanographic and geophysical data.A continuous monitoring by infrasound sensors in the Antarctic firmly contributes to the Comprehensive Nuclear-Test-Ban Treaty(CTBT) in the southern high latitude,together with the Pan-Antarctic Observations System(PAntOS) under the Scientific Committee on Antarctic Research(SCAR).Detailed measurements of the infrasound waves in Antarctica,consequently,could be a new proxy for monitoring regional environmental change as well as the temporal climate variations in the polar regions.  相似文献