Spatially resolved spectroscopy of passive spiral galaxies   总被引：1，自引：0，他引：1  

Miho Ishigaki †  Tomotsugu Goto  Hideo Matsuhara 《Monthly notices of the Royal Astronomical Society》2007,382(1):270-278

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Synoptic weather conditions and aerosol episodes over Indo-Gangetic Plains,India     

D. G. Kaskaoutis  E. E. Houssos  D. Goto  A. Bartzokas  P. T. Nastos  P. R. Sinha  S. K. Kharol  P. G. Kosmopoulos  R. P. Singh  T. Takemura 《Climate Dynamics》2014,43(9-10):2313-2331

The present study focuses on identifying the main atmospheric circulation characteristics associated with aerosol episodes (AEs) over Kanpur, India during the period 2001–2010. In this respect, mean sea level pressure (MSLP) and geopotential height of 700 hPa (Z700) data obtained from the NCEP/NCAR Reanalysis Project were used along with daily Terra-MODIS AOD₅₅₀ data. The analysis identifies 277 AEs [AOD₅₀₀ >  \( \overline{AOD} \) ₅₀₀ + 1STDEV (standard deviation)] over Kanpur corresponding to 13.2 % of the available AERONET dataset, which are seasonally distributed as 12.5, 9.1, 14.7 and 18.6 % for winter (Dec–Feb), pre-monsoon (Mar–May), monsoon (Jun–Sep) and post-monsoon (Oct–Nov), respectively. The post-monsoon and winter AEs are mostly related to anthropogenic emissions, in contrast to pre-monsoon and monsoon episodes when a significant component of dust is found. The multivariate statistical methods Factor and Cluster Analysis are applied on the dataset of the AEs days’ Z700 patterns over south Asia, to group them into discrete clusters. Six clusters are identified and for each of them the composite means for MSLP and Z700 as well as their anomalies from the mean 1981–2010 climatology are studied. Furthermore, the spatial distribution of Terra-MODIS AOD₅₅₀ over Indian sub-continent is examined to identify aerosol hot-spot areas for each cluster, while the SPRINTARS model simulations reveal incapability in reproducing the large anthropogenic AOD, suggesting need of further improvement in model emission inventories. This work is the first performed over India aiming to analyze and group the atmospheric circulation patterns associated with AEs over Indo-Gangetic Plains and to explore the influence of meteorology on the accumulation of aerosols.  相似文献   

The morphology–density relation in the Sloan Digital Sky Survey     

Tomotsugu Goto †  Chisato Yamauchi  Yutaka Fujita  Sadanori Okamura  Maki Sekiguchi  Ian Smail  Mariangela Bernardi  Percy L. Gomez 《Monthly notices of the Royal Astronomical Society》2003,346(2):601-614

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Near-Infrared Colors of the Binary Kuiper Belt Object 1998 WW 31     

Takato  Naruhisa  Fuse  Tetsuharu  Gaessler  Wolfgang  Goto  Miwa  Kanzawa  Tomio  Kobayashi  Naoto  Minowa  Yosuke  Oya  Shin  Pyo  Tae-Soo  Saint-Jacque  D.  Takami  Hideki  Terada  Hiroshi  Hayano  Yutaka  Iye  Masanori  Kamata  Yukiko  Tokunaga  A. T. 《Earth, Moon, and Planets》2003,92(1-4):183-191

We have measured near-infrared colorsof the binary Kuiper Belt object (KBO)1998 WW₃₁ using the Subaru Telescope withadaptive optics. The satellite was detectednear its perigee and apogee(0.18“ and 1.2” apart from the primary).The primary and the satellite have similar H–Kcolors, while the satellite is redder thanthe primary in J–H. Combined with the Rband magnitude previously published byVeillet et al., 2002, the color of the primaryis consistent with that of optically red KBOs. Thesatellite's R-, J-, H-colors suggest thepresence of ～1 μm absorption band dueto rock-forming minerals. If the surface of thesatellite is mainly composed by olivine, thesatellite's albedo is higher value than the canonicallyassumed value of 4%.  相似文献   

Phytoremediation of shallow organically enriched marine sediments using benthic microalgae     

Yamamoto T  Goto I  Kawaguchi O  Minagawa K  Ariyoshi E  Matsuda O 《Marine pollution bulletin》2008,57(1-5):108-115

We examined whether replantation of benthic microalgae (BMA) can remediate shallow organically enriched sediment. Nitzschia sp., the dominant species in the tested area (Hiroshima Bay, Japan), was isolated and mass cultured, then replanted in the same area. Changes in the condition of the sediment were monitored for five months. During the study period, we observed an increase in redox potential (ORP) and a decrease in acid-volatile sulfide (AVS) in the experimental area, indicating that the sediment condition changed from reduced to oxic. Organic matter in the sediment, represented by chemical oxygen demand (COD), ignition loss (IL) and organic nitrogen (ON) decreased significantly, while inorganic nutrients (ammonia and phosphate) increased in the interstitial water. These changes imply that oxygen produced by the replanted BMA may have enhanced aerobic bacterial activity, accelerating the decomposition of organic matter. Thus, replantation of BMA shows potential as a novel and promising "phytoremediation" method for organically enriched sediment.  相似文献   

Using expert knowledge to map the level of risk of shallow landslides in Brazil     

Goto  Erica Akemi  Clarke  Keith 《Natural Hazards》2021,108(2):1701-1729

Shallow landslides are common in Brazil's urban areas. Geomorphology and land use are contributing factors, and rainfall is the triggering one. In these urban areas, anthropogenic activities that increase the level of landslide risk are common, such as cutting and filling or discharging wastewater onto the slopes. The Brazilian Government has developed a methodology to map the risk level in landslide-prone areas. The methodology is based on field observation and divides the risk into four main categories: low, moderate, high, and very high. Technicians in the field decide the sector's landslide risk level based on their professional and personal experiences, but without mathematical calculations or without using specific weights for the contributing factors. This study proposes a method for automatically computing the risk level by involving many experts for deriving each classifier weight, thereby reducing the subjectivity in selecting the final risk level. The weights were calculated using the Analytical Hierarchical Process based on 23 experts on landslides, and the standard deviation was used to define the risk level threshold. We validated the study using a prior risk mapping of São Paulo city. Finally, an application (app) that can be used on a tablet, computer, or smartphone was created to facilitate data collection during fieldwork and to automatically compute the risk level. Risk areas in Brazil are frequently changing as new residents move to the area or changes in the buildings or terrain are made. In addition, mapping the risk areas is expensive and time-demanding for municipalities. Therefore, an application that gathers the data easily and automatically computes the risk level can help municipalities rapidly update their risk sectors, allowing them to use updated risk mapping during the rainy season and be less dependent on rarely available financial resources to hire a risk mapping service.

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Surface lowering rates of uplifted limestone terraces estimated from the height of pedestals on a subtropical island of Japan     

Yukinori Matsukura  Akira Maekado  Hisashi Aoki  Tetsuya Kogure  Yoshihiko Kitano 《地球表面变化过程与地形》2007,32(7):1110-1115

In Kikai‐jima, south‐western Japan, many pedestal rocks have developed on the surface of Holocene raised coral‐reef terraces with known dates of emergence. Pedestals are formed just under boulders, which are considered to have been transported by tsunami and settled on a reef flat before emergence. On the assumption that boulders protect the underlying limestone terrace from rainfall solution, the rate of surface lowering of these limestone terraces was evaluated from the height of pedestals and the period of their formation. The result showed that the mean lowering rate over 6000 years is 205 mm/ky. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Hydraulic and numerical study on the generation of a subaqueous landslide-induced tsunami along the coast   总被引：1，自引：0，他引：1  

Yoshinori Shigihara  Daichi Goto  Fumihiko Imamura  Yuichi Kitamura  Takayuki Matsubara  Kazuaki Takaoka  Kazuhiko Ban 《Natural Hazards》2006,39(2):159-177

By carrying out the hydraulic experiments in a one-dimensional open channel and two-dimensional basin, we clarified the process of how a landslide on a uniform slope causes the generation of a tsunami. The effect of the interactive force that occurs between the debris flow layer and the tsunami is significant in the generation of a tsunami. The continuous flow of the debris into the water makes the wave period of the tsunami short. The present experiments apply numerical simulation using the two-layer model with shear stress models on the bottom and interface, and the results are compared. The simulated debris flow shows good agreement with the measured results and ensures the rushing process into the water. We propose that the model use a Manning coefficient of 0.01 for the smooth slope and 0.015 for the rough slope, and a horizontal viscosity of 0.01 m²/s for the landslide; an interactive force of 0.2 for each layer is recommended. The dispersion effect should be included in the numerical model for the propagation from the shore.  相似文献   

Dynamic source inversion based on stable formulation and on identification of the resolution level via a multiscale approach     

Hiroyuki Goto  Sumio Sawada 《Geophysical Journal International》2006,167(2):779-793

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Occurrence of calcite in Sanbagawa pelitic schists: implications for the formation of garnet, rutile, oligoclase, biotite and hornblende   总被引：2，自引：0，他引：2  

A. Goto  S. Banno  T. Higashino  C. Sakai 《Journal of Metamorphic Geology》2002,20(2):255-262

The frequency of occurrence of minerals in 1876 samples of Sanbagawa pelitic schist in central Shikoku is summarized on the basis of microscopic observation accompanied, in part, by use of an electron microprobe. All samples contain quartz, plagioclase, phengite, chlorite and graphite. More than 90% of samples contain clinozoisite, titanite and apatite. Garnet is present in 95% of samples from the garnet zone, and biotite is present in 64% of samples from the albite‐biotite zone. Calcite is found in about 40% of samples of the pelitic schist collected from outcrop, but occurs in 95% of the pelitic schist from drill cores. Calcite was apparently ubiquitous in the pelitic schist during the Sanbagawa metamorphism, but must have been dissolved recently by the action of surface or ground water. The mineral assemblages of the Sanbagawa pelitic schist have to be analyzed in the system with excess calcite, quartz, albite (or oligoclase), clinozoisite, graphite and fluid that is composed mainly of H₂O, CO₂ and CH₄. In the presence of calcite, reactions that produce garnet, rutile, oligoclase, biotite and hornblende, some of which define isograds of the metamorphic belt, should be written as mixed volatile equilibria that tend to take place at lower temperature than the dehydration reactions that have been proposed. The presence of calcite in pelitic schist suggests that fluid composition is a variable as important in determining mineral assemblages as pressure and temperature. Thus Ca‐bearing phases must be taken into account to analyze the phase relations of calcite‐bearing pelitic schist, even if CaO content of Sanbagawa pelitic schist is low. As calcite is a common phase, the mineral assemblages of the biotite zone pelitic schist may contravene the mineralogical phase rule and warrant further study.  相似文献