An emission pathway for stabilization at 6?Wm?2 radiative forcing   总被引：1，自引：0，他引：1  

Toshihiko Masui  Kenichi Matsumoto  Yasuaki Hijioka  Tsuguki Kinoshita  Toru Nozawa  Sawako Ishiwatari  Etsushi Kato  P. R. Shukla  Yoshiki Yamagata  Mikiko Kainuma 《Climatic change》2011,109(1-2):59-76

Representative Concentration Pathway 6.0 (RCP6) is a pathway that describes trends in long-term, global emissions of greenhouse gases (GHGs), short-lived species, and land-use/land-cover change leading to a stabilisation of radiative forcing at 6.0 Watts per square meter (Wm^?2) in the year 2100 without exceeding that value in prior years. Simulated with the Asia-Pacific Integrated Model (AIM), GHG emissions of RCP6 peak around 2060 and then decline through the rest of the century. The energy intensity improvement rates changes from 0.9% per year to 1.5% per year around 2060. Emissions are assumed to be reduced cost-effectively in any period through a global market for emissions permits. The exchange of CO₂ between the atmosphere and terrestrial ecosystem through photosynthesis and respiration are estimated with the ecosystem model. The regional emissions, except CO₂ and N₂O, are downscaled to facilitate transfer to climate models.  相似文献   

Intraseasonal variability in the far-east pacific: investigation of the role of air�Csea coupling in a regional coupled model     

R. Justin Small  Shang-Ping Xie  Eric D. Maloney  Simon P. de Szoeke  Toru Miyama 《Climate Dynamics》2011,36(5-6):867-890

Intraseasonal variability in the eastern Pacific warm pool in summer is studied, using a regional ocean?Catmosphere model, a linear baroclinic model (LBM), and satellite observations. The atmospheric component of the model is forced by lateral boundary conditions from reanalysis data. The aim is to quantify the importance to atmospheric deep convection of local air?Csea coupling. In particular, the effect of sea surface temperature (SST) anomalies on surface heat fluxes is examined. Intraseasonal (20?C90?day) east Pacific warm-pool zonal wind and outgoing longwave radiation (OLR) variability in the regional coupled model are correlated at 0.8 and 0.6 with observations, respectively, significant at the 99% confidence level. The strength of the intraseasonal variability in the coupled model, as measured by the variance of outgoing longwave radiation, is close in magnitude to that observed, but with a maximum located about 10° further west. East Pacific warm pool intraseasonal convection and winds agree in phase with those from observations, suggesting that remote forcing at the boundaries associated with the Madden?CJulian oscillation determines the phase of intraseasonal convection in the east Pacific warm pool. When the ocean model component is replaced by weekly reanalysis SST in an atmosphere-only experiment, there is a slight improvement in the location of the highest OLR variance. Further sensitivity experiments with the regional atmosphere-only model in which intraseasonal SST variability is removed indicate that convective variability has only a weak dependence on the SST variability, but a stronger dependence on the climatological mean SST distribution. A scaling analysis confirms that wind speed anomalies give a much larger contribution to the intraseasonal evaporation signal than SST anomalies, in both model and observations. A LBM is used to show that local feedbacks would serve to amplify intraseasonal convection and the large-scale circulation. Further, Hovm?ller diagrams reveal that whereas a significant dynamic intraseasonal signal enters the model domain from the west, the strong deep convection mostly arises within the domain. Taken together, the regional and linear model results suggest that in this region remote forcing and local convection?Ccirculation feedbacks are both important to the intraseasonal variability, but ocean?Catmosphere coupling has only a small effect. Possible mechanisms of remote forcing are discussed.  相似文献   

Geological and Hydrodynamical Examination of the Bathyal Tsunamigenic Origin of Miocene Conglomerates in Chita Peninsula, Central Japan     

Toru Tachibana  Yoshinobu Tsuji 《Pure and Applied Geophysics》2011,168(6-7):997-1014

A conglomerate appears on a rocky coast called ??Tsubutega-ura Coast??, located on the southwestern coast near the southern tip of the Chita Peninsula, Aichi Prefecture, central Japan. The conglomerate belongs to Miocene sedimentary rocks termed the Morozaki Group. The conglomerate includes meter-scale boulders, indicating that it was formed by an extraordinary event. In the geological investigation, we observed that the conglomerate shows alternate changes of paleocurrent directions between seaward and landward. This feature is supposed to be formed by tsunami currents. In the hydrodynamical investigation, we obtained following results: (1) the lowest limit of a current velocity to move a boulder of about 3?m in diameter would be about 2?C3?m/s, (2) the speed of tsunami currents reproduced by tsunami simulation exceeds 3?m/s at 300?m in depth when the tsunami is generated by a gigantic earthquake with magnitude 9.0 or more, (3) the transport distance of the boulder would be several hundred?meters to several kilometers by one tsunami event caused by a gigantic earthquake. We conclude that tsunamis best explain the formation of the conglomerate deposited in upper bathyal environments about 200?C400?m depth, both from geological and hydrodynamical viewpoints.  相似文献   

Hydrothermal alteration and K–Ar ages of Neogene‐Quaternary magmatic‐hydrothermal systems at Toyoha‐Muine area in southwest Hokkaido,Japan     

Toru SHIMIZU  Masahiro AOKI 《Resource Geology》2011,61(2):192-209

This paper presents a review of hydrothermal alteration and K–Ar age data from the Toyoha‐Muine area (TMA), where the Toyoha polymetallic (Ag–Pb–Zn–Cu–In) deposit is located near the Pliocene andesitic volcano that formed Mt Muine. Systematic prospect‐scale mapping, sampling, X‐ray analysis and microscopic observation show that hydrothermal alteration is divided into two groups: acid‐pH and neutral‐pH alteration types. The former is further divided into mineral assemblages I, II and III, while the latter into mineral assemblages IV and V. Different mineralogical features in five mineral assemblages are summarized as follows: (I) Quartz (silicified rock); (II) Pyrophyllite or dickite; (III) Kaolinite or halloysite ± alunite; (IV) Sericite or K‐feldspar; and (V) Interstratified minerals (illite/smectite and chlorite/smectite) and/or smectite. K–Ar radiometric ages determined on twenty‐eight K‐bearing samples (whole volcanic rocks and separated hydrothermal minerals) mainly fall into one of three periods: Early Miocene (24.6–21.4 Ma), Middle–Late Miocene (12.5–8.4 Ma) and Pliocene–Pleistocene (3.2–0 Ma). These three periods are characterized as follows. Early Miocene: A minor hydrothermal activity, which might be genetically related to the intermediate or felsic magmatic activities, formed mineral assemblage IV at 24.6 Ma in the northern part of the TMA. Middle to Late Miocene: The basaltic intrusion, andesitic eruption, and granodiorite intrusions induced hydrothermal activities between 12.5 and 8.4 Ma, resulting in the formation of a mineral assemblage IV with some base metal mineralization. Pliocene–Pleistocene: An andesitic eruption formed Mt Muine between 3.2 and 2.9 Ma. The andesitic activity was associated with acid‐pH mineral assemblages I, II and III locally around the volcano. Latent magmatic intrusions subsequent to the andesitic eruption generated hydrothermal activities that formed mineral assemblages IV and V between 1.9 and 0 Ma in the southern and southeastern parts of Toyoha deposit at depth, overprinting the Middle to Late Miocene alteration. The hydrothermal activities also formed mineral assemblages I, II and III along the Yunosawa fault (east of the Toyoha deposit) and assemblage III in the south and southeast of the Toyoha deposit near the surface.  相似文献   

Characteristics of the ratio of dissolved cadmium to phosphate in subtropical coastal waters of Ishigaki Island,Okinawa, Japan     

Kazuo Abe  Kouki Fukuoka  Toru Shimoda 《Journal of Oceanography》2011,67(2):241-248

The ratio of dissolved cadmium (Cd) to phosphate (PO₄) in the subtropical coastal area of Ishigaki Island, Okinawa, Japan, was investigated. Twenty vertical seawater samplings were carried out once a month from May 2008 to January 2010. In order to examine how the Cd/PO₄ ratio in seawater varies with the oceanographic conditions (i.e., the water temperature–salinity characteristics), the water masses at the study sites were classified into two types: group 1 with a water temperature of >25°C and a salinity range of 34.0–34.4, and group 2 with a water temperature of <25°C and a salinity of >34.4. A different phytoplankton assemblage was observed in each water mass defined. Different Cd/PO₄ ratios were obtained for the two water mass types, due to the differences between the types in terms of the environmental conditions such as the water temperature–salinity (T–S) characteristics and phytoplankton assemblages, as well as possible variations in the concentrations of dissolved iron, zinc, manganese, and CO₂ in seawater in each water mass.  相似文献   

Hayabusa‐returned sample curation in the Planetary Material Sample Curation Facility of JAXA     

Toru YADA  Akio FUJIMURA  Masanao ABE  Tomoki NAKAMURA  Takaaki NOGUCHI  Ryuji OKAZAKI  Keisuke NAGAO  Yukihiro ISHIBASHI  Kei SHIRAI  Michael E. ZOLENSKY  Scott SANDFORD  Tatsuaki OKADA  Masayuki UESUGI  Yuzuru KAROUJI  Maho OGAWA  Shogo YAKAME  Munetaka UENO  Toshifumi MUKAI  Makoto YOSHIKAWA  Junichiro KAWAGUCHI 《Meteoritics & planetary science》2014,49(2):135-153

Abstract– The Planetary Material Sample Curation Facility of JAXA (PMSCF/JAXA) was established in Sagamihara, Kanagawa, Japan, to curate planetary material samples returned from space in conditions of minimum terrestrial contaminants. The performances for the curation of Hayabusa‐returned samples had been checked with a series of comprehensive tests and rehearsals. After the Hayabusa spacecraft had accomplished a round‐trip flight to asteroid 25143 Itokawa and returned its reentry capsule to the Earth in June 2010, the reentry capsule was brought back to the PMSCF/JAXA and was put to a series of processes to extract recovered samples from Itokawa. The particles recovered from the sample catcher were analyzed by electron microscope, given their ID, grouped into four categories, and preserved in dimples on quartz slide glasses. Some fraction of them has been distributed for initial analyses at NASA, and will be distributed for international announcement of opportunity (AO), but a certain fraction of them will be preserved in vacuum for future analyses.  相似文献   

Investigation of cutting methods for small samples of Hayabusa and future sample return missions     

Masayuki Uesugi  Ryo Noguchi  Tooru Matsumoto  Junya Matsuno  Takashi Nagano  Akira Tsuchiyama  Shigenori Harada  Kaori Yokoyama  Yoshiaki Yodo  Noboru Takeda  Toru Yada  Shogo Yakame  Yuzuru Karouji  Yukihiro Ishibashi  Masanao Abe  Tatsuaki Okada  Akio Fujimura  Mitsuru Ebihara  Fumio Kitajima  Keisuke Nagao  Tomoki Nakamura  Hiroshi Naraoka  Takaaki Noguchi  Ryuji Okazaki  Hisayoshi Yurimoto 《Meteoritics & planetary science》2014,49(7):1186-1201

We report the investigation of cutting methods for Hayabusa samples. The purpose of our study is to explore the possibility of applying multiple analyses to a single particle effectively. We investigated the cutting performance of a blade dicing saw, laser, focused ion beam (FIB), and physical breaking by microindenter. Cutting performance was examined by estimating the aspect ratio of the cut slit, i.e., depth over width of the slit. We also investigated the possible contamination and sample damage by cutting. The result of the investigation shows that we can cut the samples from <50 μm to 500 μm using those methods with aspect ratios from 10 to 20, although they would introduce some contamination or damage to the samples. Our investigations also provide an important basis for the analysis of samples obtained by future sample return missions.  相似文献   

Three‐dimensional microstructure of samples recovered from asteroid 25143 Itokawa: Comparison with LL5 and LL6 chondrite particles     

Akira Tsuchiyama  Masayuki Uesugi  Kentaro Uesugi  Tsukasa Nakano  Ryo Noguchi  Toru Matsumoto  Junya Matsuno  Takashi Nagano  Yuta Imai  Akira Shimada  Akihisa Takeuchi  Yoshio Suzuki  Tomoki Nakamura  Takaaki Noguchi  Masanao Abe  Toru Yada  Akio Fujimura 《Meteoritics & planetary science》2014,49(2):172-187

In this study, the three‐dimensional (3‐D) microstructure of 48 Itokawa regolith particles was examined by synchrotron microtomography at SPring‐8 during the preliminary examination of Hayabusa samples. Moreover, the 3‐D microstructure of particles collected from two LL6 chondrites (Ensisheim and Kilabo meteorites) and an LL5 chondrite (Tuxtuac meteorite) was investigated by the same method for comparison. The modal abundances of minerals, especially olivine, bulk density, porosity, and grain size are similar in all samples, including voids and cracks. These results show that the Itokawa particles, which are surface materials from the S‐type asteroid Itokawa, are consistent with the LL chondrite materials in terms of not only elemental and isotopic composition of the minerals but also 3‐D microstructure. However, we could not determine whether the Itokawa particles are purely LL5, LL6, or a mixture of the two. No difference between the particles collected from Rooms A and B of the sample chamber, corresponding to the sampling sequence of the spacecraft's second and first touchdowns, respectively, was detected because of the statistically small amount of particles from Room B.  相似文献   

Crystallization temperature determination of Itokawa particles by plagioclase thermometry with X‐ray diffraction data obtained by a high‐resolution synchrotron Gandolfi camera     

Masahiko Tanaka  Tomoki Nakamura  Takaaki Noguchi  Aiko Nakato  Hatsumi Ishida  Toru Yada  Kei Shirai  Akio Fujimura  Yukihiro Ishibashi  Masanao Abe  Tatsuaki Okada  Munetaka Ueno  Toshifumi Mukai 《Meteoritics & planetary science》2014,49(2):237-244

The crystallization temperatures of Itokawa surface particles recovered by the space probe Hayabusa were estimated by a plagioclase geothermometer using sodic plagioclase triclinicity. The Δ131‐index required for the thermometer, which is the difference in X‐ray diffraction peak positions between the 131 and 11 reflections of plagioclase, was obtained by a high‐resolution synchrotron Gandolfi camera developed for the third generation synchrotron radiation beamline, BL15XU at SPring‐8. Crystallization temperatures were successfully determined from the Δ131‐indices for four particles. The observed plagioclase crystallization temperatures were in a range from 655 to 660 °C. The temperatures indicate crystallization temperatures of plagioclases in the process of prograde metamorphism before the peak metamorphic stage.  相似文献   

Hα and HeI emission in the jets of pre-main sequence stars – implications for the heating mechanisms     

M. Takami  A. Chrysostomou  J. Bailey  T.M. Gledhill  M. Tamura  H. Terada 《Astrophysics and Space Science》2003,287(1-4):143-146

Jets and winds in pre-main sequence (PMS) stars are often heated and ionized, and understanding their heating mechanism is desired to compare UV-to-IR spectral signatures with models and thus investigate their driving mechanism. We review our results of long-slit spectroscopy and spectro-astrometry for He I 1.083 μm and Hα emission, and investigate the heating mechanisms in the jet in the outer (>10 AU) and inner (<10 AU) regions, respectively.  相似文献