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101.
Evaluation of ADEOS-II GLI ocean color atmospheric correction using SIMBADA handheld radiometer data
Hajime Fukushima Mitsuhiro Toratani Hiroshi Murakami Pierre-Yves Deschamps Robert Frouin Akihiko Tanaka 《Journal of Oceanography》2007,63(3):533-543
The performance of the “version 2” Global Imager (GLI) standard atmospheric correction algorithm, which includes empirical
absorptive aerosol correction and sun glint correction, was evaluated using data collected with handheld above-water SIMBADA
radiometers during 23 cruises of opportunity (research vessels, merchant ships), mostly in the North Atlantic and European
seas. A number of 100 match-up data sets of GLI-derived and SIMBADA-measured normalized water-leaving radiance (nL
W
) and aerosol optical thickness (AOT) were sorted out, using objective selection criteria, and analyzed. The Root-Mean-Square
(RMS) difference between GLI and SIMBADA nL
W
was about 0.32 μW/cm2/nm/sr for the 412 nm band, showing improvement by 30% in RMS difference with respect to the conventional “version 1” GLI
atmospheric correction algorithm, and the mean difference (or bias) was reduced significantly. For AOT, the RMS difference
was 0.1 between GLI estimates and SIMBADA measurements and the bias was small (a few 0.01), but the ?ngstr?m exponent was
systematically underestimated, by 0.4 on average, suggesting a potential GLI calibration offset in the near infrared. The
nL
W
differences were not correlated to AOT, although performance was best in very clear conditions (AOT less than 0.05 in the
865 nm band). Despite the relatively large scatter between estimated and measured nL
W
, the derived chlorophyll-a concentration estimates, applying the same ratio algorithm (GLI OC4V4) to GLI and SIMBADA, were
consistent and highly correlated in the range of 0.05–2 μg/l. The large variability in chlorophyll-a concentration estimate
for clear clean water areas (e.g. with the concentration range lower than about 0.05 μg/l) turns out to be due to the nature
of the “band ratio” based in-water algorithm. 相似文献
102.
Shota Mochizuki Takuhiko Murakami 《International Journal of Applied Earth Observation and Geoinformation》2011
The aim of this study was to evaluate changes in macaque habitat selection during a 29-year period. We focused on the 1970s, when little crop damage was caused by Japanese macaques (Macaca fuscata), and the 2000s, when the damage became remarkable. Landsat/MSS from 1978 and ALOS/AVNIR-2 from 2007 were employed for land-cover mapping. For the 2007 land-cover classification, we applied an object-oriented image classification and a classification and regression tree. The Kappa coefficient of the 2007 land-cover map was 0.89. For the 1978 land-cover classification, change detection using principal component analysis and object-oriented image classification were applied to reduce resolution difference errors. The Kappa coefficient of the 1978 land-cover map was 0.84. We applied a Random Forest model for machine learning and data mining to predict the habitat selection of macaques. Several important environmental factors were identified for macaque habitat selection: the ratio of coniferous forest to farmland, distance to farmland, and maximum snow depth. The Random Forest model was extrapolated to the 1978 land-cover map. Over the 29-year period, coniferous forest changed to broad-leaved forest and/or mixed forest within the macaque habitat area. Coniferous forests were not selected as food resources by Japanese macaques. Furthermore, large-scale patches of farmland were used as food resources over the 29-year period. These changes indicated that habitat selection by Japanese macaques changed over the study period. The results show that the home range of macaques expanded, and macaques may now be distributed over a wider area as a result of changes in landscape configuration. Thus, forest planning, such as sustainable management of artificial conifer forests, is important for reducing crop damage. 相似文献
103.
104.
Jun-Young Song Kei Nakayama Yasunori Murakami Sung-Ju Jung Myung-Joo Oh Satoru Matsuoka Hidemasa Kawakami Shin-Ichi Kitamura 《Marine pollution bulletin》2008,57(6-12):889
As basic research for the effect of heavy oil on the fish immune system, in this study, the number of leukocyte was counted in Japanese flounder Paralichthys olivaceus, after exposure to heavy oil at a concentration of 30 g/8 L for 3 days. To compare the numbers of bacteria in the skin mucus between oil-exposed and control fish, viable bacteria were enumerated by counting colony forming unit (CFU). Compared with 5.79 ± 1.88 × 107 leukocytes/mL in the controls, the exposed fish demonstrated higher counts, averaging 1.45 ± 0.45 × 108 cells/mL. The bacterial numbers of control fish were 4.27 ± 3.68 × 104 CFU/g, whereas they were 4.58 ± 1.63 × 105 CFU/g in the exposed fish. The results suggest that immune suppression of the fish occurred due to heavy oil stressor, and bacteria could invade in the mucus, resulting in the increasing leukocyte number to prevent infectious disease. 相似文献
105.
Application of an earthquake early warning system and a real-time strong motion monitoring system in emergency response in a high-rise building 总被引:1,自引:0,他引:1
Tomohiro Kubo Yoshiaki Hisada Masahiro Murakami Fusako Kosuge Kohei Hamano 《Soil Dynamics and Earthquake Engineering》2011
We apply a combination of earthquake early warning system (EEWS) and real-time strong motion monitoring system (RSMS) to emergency response for a high-rise building; The Kogakuin University has a 29-story high-rise building in Shinjuku Ward, Tokyo. The proposed strategy is based on the Plan, Do, Check, Action (PDCA) Cycle to brush up the systems and the users: in the “Plan” stage, we apply EEWS and RSMS to the building, where EEWS predicts not only short-period strong ground motions but also long-period ground motions [1]. The system is built into a building announcement system, an emergency elevator control system, and an email message system, which quickly send emails to the emergency response team. Meanwhile, RSMS provides information on seismic intensities at each floor of the building via the web browser in real time using the existing network in the building. In addition, the building response and structural damage can be estimated based on this information. The network system is impervious to the earthquake damage, because the network cable has extra length, there is, however, possible that a network system does not work due to power outage. Thus, we develop the network system that has uninterruptible power-supply system (UPS) and apply it to EEWS and RSMS. The high-rise building has the emergency call units to the security control center in the building on every floor. The emergency call line, however, will be busy promptly, because it is able to use only one line. Therefore, we installed IP telephone which uses the network system on main floors. UPS will work about 30 min after a major earthquake, it is supposed to be enough time for gathering the damage information about the building during initial response. In the “Do” stage, we prepare emergency response instruction manuals and educate the faculty members and students to carry out promptly emergency response. In the “Check” stage, the validity of the proposed systems are verified by carrying out an earthquake drill in an actual high-rise building. The earthquake drill confirmed that our proposed approach is valid. In the final “Action” stage, we improve these systems and emergency response manual and educate people in the building how to use effectively these systems. 相似文献
106.
Analysis of various large-scale disturbances and the associated zonal mean motions in the atmosphere
Takio Murakami 《Pure and Applied Geophysics》1963,54(1):119-165
Summary In this article, we present a scale analysis of planetary waves, extended long waves, and long waves. (We mean the extended long waves to be the disturbances whose east-west length is of order 106 m and north-south extension 107 m). We find for the extended long waves the two terms, the interaction between kinetic and available potential energy of the disturbances, and the interaction between the zonal mean available potential energy, and the eddy available potential energy, are of two orders of magnitude larger than the kinetic energy interaction between the disturbances and the associated zonal mean flow. This theoretical result concerning the relative importance of the various interaction terms may be of use in explaining the observational findings thus far available.It is also shown theoretically that the kinetic energy interaction between the planetary waves, the horizontal size of which is 107 m, and the long waves, whose horizontal size is 106 m, is of the same order as the interaction of kinetic energy between the zonal mean motion and the disturbances. This agrees fairly well with the observational estimates thus far obtained. 相似文献
107.
Monitoring and simulation of water, heat,and CO2 fluxes in terrestrial ecosystems based on the APEIS-FLUX system 总被引:2,自引:0,他引:2
WATANABEMasataka WANGQinxue HAYASHISeiji MURAKAMIShogo LIUJiyuan OUYANGZhu LIYan LIYingnian WANGKelin 《地理学报(英文版)》2005,15(2):131-141
1IntroductionInJune1992,theworldsummitorganizedbytheUnitedNations,withparticipantsincludingnationalleadersfromaroundtheworld,concludedwithAgenda21(UnitedNations,1992),theRioDeclarationonEnvironmentandDevelopment,inRiodeJaneiro.Thedeclarationpromptedcountr… 相似文献
108.
Ichiro Yoshikawa Junya Ono Go Murakami Shingo Kameda 《Planetary and Space Science》2008,56(13):1676-1680
A rare, but normal, astronomical event occurred on November 9th 2006 (JST) as Mercury passed in front of the Sun from the perspective of the Earth. The abundance of the sodium vapor above the planet limb was observed by detecting an excess absorption in the solar sodium line D1 during this event. The observation was performed with a 10-m spectrograph of Czerny-Turnar system at Domeless Solar Tower Telescope at the Hida Observatory in Japan. The excess absorption was red-shifted by 10 pm relative to the solar line, and was measured at the dawnside (eastside) and duskside (westside) of Mercury. Between the dawn and dusksides, an asymmetry of total sodium abundance was clearly identified. At the dawnside, the total sodium column density was 6.1×1010 Na atoms/cm2, while it was 4.1×1010 Na atoms/cm2 at the duskside. The investigation of dawn-dusk asymmetry of the sodium exosphere of Mercury is a clue to understand the release mechanism of sodium from the surface rock. Our result suggests that a thermal desorption is a main source process for sodium vapor in the vicinity of Mercury. 相似文献
109.
Ryosuke Takamatsu Kazunori Fujisawa Kazuyuki Nakahata Akira Murakami 《国际地质力学数值与分析法杂志》2020,44(15):2025-2041
A numerical technique for detecting the number and shape of subsurface cavities is presented, applying the particle filter and the parametric level set method to elastic wave propagation under the ground. When subsurface cavities exist, the elastic wave propagating in the ground is reflected at the boundary faces of the cavities. Observing the velocity of the reflection wave at the surface of a ground that includes multiple cavities and parameterizing the shape of the cavities by the parametric level function, both the number and the shape of the cavities can be identified by the particle filter. Numerical experimentation for detecting multiple cavities is conducted with synthetic observation data. The results show that the proposed technique enables the number of cavities to be identified by the number of peaks in the posterior probabilistic distribution function and solves geometric inverse problems by estimating the shape of the cavities through the parameter identification of the level set function. 相似文献
110.
H. Yoshida R. Metcalfe K. Yamamoto Y. Murakami D. Hoshii A. Kanekiyo T. Naganuma T. Hayashi 《Applied Geochemistry》2008,23(8):2364-2381
Subsurface redox fronts control the mobilization and fixation of many trace elements, including potential pollutants such as certain radionuclides. Any safety assessment for a deep geological repository for radioactive wastes needs to take into account adequately the long-term redox processes in the geosphere surrounding the repository. To build confidence in understanding these processes, a redox front in a reduced siliceous sedimentary rock distributed in an uplifting area in Japan has been studied in detail. Geochemical analyses show increased concentrations of Fe and trace elements, including rare earth elements (REEs), at the redox front, even though concentrations of reduced rock matrix constituents show little change. Detailed SEM observations revealed that fossilized microorganisms composed of amorphous granules made exclusively of Fe and Si occur in the rock’s pore space. Microbial 16S rDNA analysis suggests that there is presently a zonation of different bacterial groups within the redox band, and bacterial zonation played an important role in the concentration of Fe-oxyhydroxides at the redox front. These water–rock–microbe interactions can be considered analogous to the processes occurring in the redox fronts that would develop around geological repositories for radioactive waste. Once formed, the Fe-oxyhydroxides within such a front would be preserved even after reducing conditions resume following repository closure. 相似文献