The Early Summer Seasonal Change of Large－scale Circulation over East Asia and Its Relation to Change of The Frontal Features and Frontal Rainfall Environment During 1991 Summer

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An emission pathway for stabilization at 6?Wm?2 radiative forcing

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.     

Numerical simulations of pulsationally unstable accretion disks around supermassive black holes

The innermost region of slim accretion disks with standard viscosity is unstable against axisymmetric radial inertial acoustic perturbations under certain conditions. Numerical simulations are performed in order to demonstrate behaviors of such unstable disks. It is shown that oscillations with the period of 10^–3 (M _BH/M ) s can be excited near the inner edge of the disks, whereM _BH is the mass of the central object. This kind of unstable disks is a possible origin of the periodic X-ray time variabilities with period of 10⁴s observed in a Seyfert galaxy NGC 6814.     

Experimental investigation of the α-β transformation of San Carlos olivine single crystal

Single crystalline San Carlos olivine (1 mm cube) was transformed to (Mg,Fe)₂SiO₄β-phase at 13.5–15 GPa, 1030–1330 °C for 0–600 min using a multi-anvil high pressure apparatus. The α-β transformation occurred by incoherent surface nucleation and interface-controlled growth and recovered partially transformed samples showed sharply defined reaction rim. The growth rate of the β-phase rim significantly decreased with time and the growth eventually ceased. TEM observations revealed that many dislocations were created in both the relict olivine just near the α-β interface and the β-phase in the rim, which show evidence for deformation caused by interfacial stresses associated with the misfit elastic strain of the transformation. The observed tangled dislocation texture in β-phase suggested that the β-phase rim was hardened and relaxation of the interfacial stress was retarded. This probably caused a localized pressure drop in the relict olivine and decreased the growth rate. Time-dependent growth rates of β-phase is possibly controlled by the rheology of β-phase, which must be considered for the prediction of the olivine metastability in the subducting slabs. Received: 24 January 1997 / Revised, accepted: 24 July 1998     

Geotraverse across the Sikhote Alin — The Sea of Japan — The Honshu Island — The Pacific

The paper presents the results of geological-geophysical research carried out during the Soviet-Japanese cooperative study of the structure and dynamics of the Earth's crust and upper mantle in the transition zone from the Pacific Ocean to the Asian continent. The 300 km deep geological-geophysical section of the tectonosphere (geotraverse) has been compiled on the basis of combined interpretations of seismic, geological, petrographic, gravimetric, magnetometric, electromagnetic and heat flow measurements. Estimates were made of deep temperatures along the geotraverse and of the depths of the partial melting level that can be identified with the upper boundary of the asthenosphere.     

Giant Megamullion in the Parece Vela Backarc Basin

We present results of high-resolution bathymetric studies of the extinct intermediate-spreading Parece Vela Basin in the northwestern Pacific, where we have identified an extremely large mullion structure, here termed a giant megamullion. We find that the giant megamullion is nearly an order of magnitude larger than the similar structures in the slow-spreading Mid-Atlantic Ridge (`megamullions'). The giant megamullion has slightly elevated mantle Bouguer anomaly, and yields serpentinized peridotites and gabbros, suggesting that they are exposing oceanic crust and upper mantle. An off-axis rugged `chaotic terrain' was also identified in the Parece Vela Basin. The terrain consists of isolated and elevated blocks capped by corrugated axis-normal lineations, and associated deeps. We thus interpret it as analogues to the Mid-Atlantic Ridge megamullions. We propose that amagmatic tectonics producing the giant megamullion and the chaotic terrain occupied a significant part in crustal construction in the Parece Vela Basin evolution.     

How do “numbers” construct social reality in disaster-stricken areas?: a case of the 2008 Wenchuan earthquake in Sichuan,China

This article focuses on the dynamics of using numbers to construct an image of social reality in disaster areas. Numbers are neither objective nor value-neutral but are rather generated, transmitted and shared with social signification. In other words, numbers can be thought of as simply socially constructed information. Statistics and other numbers usually work in positive ways. However, it is also possible that using numbers in the media can lead to unintended messages that could produce negative consequences. We conducted field studies in disaster-stricken areas of the 2008 Wenchuan earthquake in China and compared findings to the case of the 1995 Kobe earthquake in Japan in order to examine how numbers—in terms of the amount of donations, the timeline of reconstruction projects and casualty figures—construct social reality and cause a variety of social dysfunctions.     

Coronal Magnetic Field Context of Simple CMEs Inferred from Global Potential Field Models

Most work on coronal mass ejection (CME) interpretation focuses on the involved active region rather than on the large-scale coronal context. In this paper a global potential-field source-surface model of the coronal magnetic field is used to evaluate the sensitivity of the coronal field configuration to the location, orientation, and strength of a bipolar active region relative to a background polar field distribution. The results suggest that the introduction of antiparallel components between the field of the active region and the background field can cause significant topological changes in the large-scale coronal magnetic field resembling observations during some simple CMEs. Antiparallel components can be introduced in the real corona by the diffusion and convection of photospheric fields, flux emergence, or erupted or shear-induced twist of active-region fields. Global MHD models with time-dependent boundary conditions could easily test the stability of such configurations and the nature of any related transients.     

Non-intrusive measurements of crater growth

An experimental technique to measure crater growth is presented whereby a high speed video captures profiles of a crater forming after impact obtained using a vertical laser sheet centered on the impact point. Unlike previous so called “quarter-space experiments,” where projectiles were launched along a transparent Plexiglas sheet so that growth of half a crater could be viewed, the use of the laser sheet permits viewing changes in crater shape without any physical interference to the cratering process. This technique indicates that for low velocity impacts (<300 m/s) into 220 μm glass beads that are without cohesion and where the projectile is not disrupted, craters initially grow somewhat proportionally, but that later their depths remain essentially constant while their diameters continue to expand. In addition, these experiments indicate that as the impact velocity increases, the rate of growth and the transient depth to diameter ratio at the end of ejecta excavation decreases. These last two observations are probably due to the large time of penetration of the projectile, which becomes a significant fraction of the time of crater formation. This is contrary to the expectations for the scaling rules, which assumes a point source. Very high curtain angles (>45°) are also seen, and could be due to the low friction angle of the target. Significant crater modification, which is rarely seen in “quarter-space experiments,” is also observed and appears to be controlled by the dynamic angle of repose of the target. These latter observations indicate that differences in target friction angles may need to be considered when determining near rim ejecta-mass distributions and large-scale crater modification processes on the planets.