Influence of Changes in Solar Radiation on Changes of Surface Temperature in China          下载免费PDF全文

ZHANG Hu  YIN Qing  Teruyuki NAKAJIMA  Nakata Mukai MAKIKO  LU Peng  HE Jinhai 《Acta Meteorologica Sinica》2013,27(1):87-97

The long-term trends of total surface solar radiation(SSR),surface diffuse radiation,and surface air temperature were analyzed in this study based on updated 48-yr data from 55 observational stations in China,and then the correlation between SSR and the diurnal temperature range(DTR) was studied.The effect of total solar radiation on surface air temperature in China was investigated on the basis of the above analyses.A strong correlation between SSR and DTR was found for the period 1961-2008 in China.The highest correlation and steepest regression line slope occurred in winter,indicating that the solar radiation effect on DTR was the largest in this season.Clouds and water vapor have strong influences on both SSR and DTR,and hence on their relationship.The largest correlations between SSR and DTR occurred in wintertime in northern China,regardless of all-day(including clear days and cloudy days) or clear-day cases.Our results also showed that radiation arriving at the surface in China decreased significantly during 1961-1989(dimming period),but began to increase during 1990-2008(brightening period),in agreement with previous global studies.The reduction of total SSR offset partially the greenhouse warming during 1961-1989.However,with the increase of SSR after 1990,this offsetting effect vanished;on the contrary,it even made a contribution to the accelerated warming.Nonetheless,the greenhouse warming still played a controlling role because of the increasing of minimum and mean surface temperatures in the whole study period of 1961-2008.We estimated that the greenhouse gases alone may have caused surface temperatures to rise by 0.31-0.46℃(10 yr) 1 during 1961-2008,which is higher than previously estimated.Analysis of the corresponding changes in total solar radiation,diffuse radiation,and total cloud cover indicated that the dimming and brightening phenomena in China were likely attributable to increases in absorptive and scattering aerosols in the atmosphere,respectively.  相似文献   

XMM–Newton observations of UW CrB: detection of X-ray bursts and evidence for accretion disc evolution     

Pasi Hakala  Gavin Ramsay  Panu Muhli  Phil Charles  Diana Hannikainen  Koji Mukai  Osmi Vilhu 《Monthly notices of the Royal Astronomical Society》2005,356(3):1133-1138

UW CrB (MS 1603+2600) is a peculiar short-period X-ray binary that exhibits extraordinary optical behaviour. The shape of the optical light curve of the system changes drastically from night to night, without any changes in overall brightness. Here we report X-ray observations of UW CrB obtained with XMM–Newton . We find evidence for several X-ray bursts, confirming a neutron star primary. This considerably strengthens the case that UW CrB is an accretion disc corona system located at a distance of at least 5–7 kpc (3–5 kpc above the Galactic plane). The X-ray and Optical Monitor (ultraviolet–optical) light curves show remarkable shape variation from one observing run to another, which we suggest are due to large-scale variations in the accretion disc shape resulting from a warp that periodically obscures the optical and soft X-ray emission. This is also supported by the changes in phase-resolved X-ray spectra.  相似文献   

Multiple scattering in the atmosphere with a rough surface     

Sonoyo Mukai 《Astrophysics and Space Science》1977,51(1):165-172

In the present paper, the intensity of radiation emergent from the atmosphere bounded by a rough surface is discussed with the aid of the superposition method derived by Mukai (1973). The merit of this method is to express the laws of diffuse reflection and transmission for the planetary problem with a rough surface in terms of a scattering and a transmission function for the standard problem.Here the bottom surface is assumed to reflect light in accordance with the slope distribution given by Cox and Munk (1954a, b). The results are discussed in terms of the optical properties and roughness of the bottom surface.  相似文献   

X-ray observations of 4 Draconis: symbiotic binary or cataclysmic triple?     

Peter J. Wheatley  Koji Mukai †  Domitilla de Martino 《Monthly notices of the Royal Astronomical Society》2003,346(3):855-860

We present the first X-ray observations of the 4 Draconis system, consisting of an M3 III giant with a hot ultraviolet companion. It has been claimed that the companion is itself an AM Her-type binary system, an identification that places strong constraints on the evolution of cataclysmic variables. We find that the X-ray properties of 4 Draconis are consistent with the presence of an accreting white dwarf, but not consistent with the presence of an AM Her system. We conclude that 4 Draconis is therefore most likely a symbiotic binary containing a white dwarf accreting material from the wind of the red giant.
The X-ray spectrum of 4 Draconis is sometimes dominated by partially ionized photoelectric absorption, presumably due to the wind of the red giant. We note that X-ray monitoring of such systems would provide a powerful probe of the wind and mass-loss rate of the giant, and would allow a detailed test of wind accretion models.  相似文献   

Substorm observations in the early morning sector with Equator-S and Geotail     

R. Nakamura  G. Haerendel  W. Baumjohann  A. Vaivads  H. Kucharek  B. Klecker  E. Georgescu  J. Birn  L. M. Kistler  T. Mukai  S. Kokubun  P. Eglitis  L. A. Frank  J. B. Sigwarth 《Annales Geophysicae》1999,17(12):1602-1610

Data from Equator-S and Geotail are used to study the dynamics of the plasma sheet observed during a substorm with multiple intensifications on 25 April 1998, when both spacecraft were located in the early morning sector (03–04 MLT) at a radial distance of 10–11 R_E. In association with the onset of a poleward expansion of the aurora and the westward electrojet in the premidnight and midnight sector, both satellites in the morning sector observed plasma sheet thinning and changes toward a more tail-like field configuration. During the subsequent poleward expansion in a wider local time sector (20−04 MLT), on the other hand, the magnetic field configuration at both satellites changed into a more dipolar configuration and both satellites encountered again the hot plasma sheet. High-speed plasma flows with velocities of up to 600 km/s and lasting 2–5 min were observed in the plasma sheet and near its boundary during this plasma sheet expansion. These high-speed flows included significant dawn-dusk flows and had a shear structure. They may have been produced by an induced electric field at the local dipolarization region and/or by an enhanced pressure gradient associated with the injection in the midnight plasma sheet.  相似文献   

Effective force testing using a robust loop shaping controller     

Narutoshi Nakata 《地震工程与结构动力学》2013,42(2):261-275

Effective force testing (EFT) is one of the force‐based experimental methods used for performance evaluation of structures that incorporate dynamic force control using hydraulic actuators. Although previous studies have shown successful implementations of force control, controllable frequency ranges are limited to low frequencies (10 Hz). This study presents the EFT method using a robust loop shaping force feedback controller that can extend the frequency range up to 25 Hz or even higher. Unlike the conventional PID controllers, loop shaping controllers can provide robustness for a high level of force measurement noise. This study investigates the dynamic properties of hydraulic actuators and the design of a loop shaping controller that compensates for control–structure interaction and suppresses the effect of oil‐column resonance. The designed loop shaping controller was successfully implemented into an EFT setup at the Johns Hopkins University. An experimental investigation of the loop shaping controller was performed under step, random, and earthquake force loadings. Experimental results showed that the loop shaping controller provided excellent force tracking performance and robustness for dynamic force loadings. It was also shown that the loop shaping controller had the gain margin of 9.54 dB at the frequency of 28 Hz. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Multidegrees‐of‐freedom effective force testing: a feasibility study and robust stability assessment     

Narutoshi Nakata  Erin Krug 《地震工程与结构动力学》2013,42(13):1985-2002

This paper presents a feasibility study of multidegrees‐of‐freedom effective force testing (MDOF‐EFT). The study is intended to facilitate the development of a force feedback controller and investigation of performance as well as robustness of MDOF‐EFT. First, the dynamics of MDOF‐EFT systems are analytically investigated. Analytical transfer functions of the control plant, the valve‐to‐force relations, showed that the plant is dynamically coupled and the natural frequencies of test structures are the transmission zeros of the plant. Using a set of model parameters from a previous study, a case study that includes controller design, numerical simulations and robust stability assessment is performed. A decoupling loop shaping (DLS) controller consisting of a pseudo inverse of the plant and second‐order loop shaping controllers is adopted as the force feedback controller. It is shown that the DLS controller provides a stable control system while successfully decoupling the control loops and compensating the control‐structure interaction. Numerical simulations demonstrate that the DLS controller enables tracking of static and dynamic forces for multiple actuators. Robust stability of MDOF‐EFT with the DLS controller is assessed using Monte Carlo simulation. The stochastic simulation results show that the DLS controller is stable and robust, providing sufficient stability margins for uncertain models with maximum 50% errors in the estimated system parameters. This paper demonstrates that MDOF‐EFT is feasible with the DLS controller and can be implemented in experimental laboratories. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

Distribution of local Cs anomalies on the seafloor near the Fukushima Dai-ichi Nuclear Power Plant     

Blair Thornton  Seiki Ohnishi  Tamaki Ura  Naoteru Odano  Shun Sasaki  Tsuneo Fujita  Tomowo Watanabe  Kaoru Nakata  Tsuneo Ono  Daisuke Ambe 《Marine pollution bulletin》2013

An estimated 3.5 ± 0.7 × 10¹⁵ Bq of ¹³⁷Cs is thought to have been discharged into the ocean following the melt down at Fukushima Dai-ichi Nuclear Power Plant (F1NPP). While efforts have been made to monitor seafloor radiation levels, the sampling techniques used cannot capture the continuous distribution of radionuclides. In this work, we apply in situ measurement techniques using a towed gamma ray spectrometer to map the continuous distribution of ¹³⁷Cs on the seafloor within 20 km of the F1NPP. The results reveal the existence of local ¹³⁷Cs anomalies, with levels of ¹³⁷Cs an order of magnitude higher than the surrounding seafloors. The sizes of the anomalies mapped in this work range from a few meters to a few hundreds of meters in length, and it is demonstrated that the distribution of these anomalies is strongly influenced by meter scale features of the terrain.  相似文献   

Stable carbon isotope behaviour of natural seepage of deep underground C-rich methane detected along a fault zone and adsorbed in mudstone: Tokyo Bay area,Japan     

E. Nakata  S. Tanaka  H. Suenaga  Y. Mahara  T. Nakamura  K. Nakagawa  T. Ohta 《Applied Geochemistry》2012

Gas was sampled regionally, including by drilling into faults, in the South Kanto gas-field around Tokyo Bay, Japan. Gas samples were collected from cores in a gas sampling container immediately after drilling. A value of δ¹³C₁ = −44.3‰ was obtained for gas in the container and δ¹³C₁ = −36.3‰ for seeping gas in a fault zone. However, typical CH₄ in this dissolved-in-water gas-field is mainly depleted in ¹³C, and δ¹³C₁ values range from −66‰ to −68‰ owing to microbial degradation of organic material. ¹³C-rich CH₄ is so far uncommon in the South Kanto gas-field. Seepages were observed from the surface along the north–south fault zone. The natural gas is stored below the sandstone layer by impermeable mudstone underlying the boundary at a depth of 30 m. Gas seepages were not observed below a depth of 40 m. Gas rises along the fault zone dissolved-in-groundwater up to the shallow region and then separates from the groundwater. ¹³C-rich CH₄ (adsorbed CH₄) was found to have desorbed from drilled mudstone core samples taken at depths of 1400–1900 m in the main gas-production strata. Similarly, ¹³C-rich CH₄ was found in black shale overlying the oceanic crust forming part of a sedimentary accretionary prism underling the Tokyo region. It also appears in the spring-water of spa wells, originating at a depth of 1200–1500 m along a tectonic line. Methane generated by microbial degradation of organic material through CO₂ reduction in the South Kanto gas-field mainly originates as biogenic gas mixed with a small amount of ¹³C-rich CH₄, derived from thermogenic gas without oil components in strata. It is assumed that ¹²C-rich CH₄ is easily detached from core or pore water through gas production, whereas ¹³C-rich CH₄ is strongly adsorbed on the surfaces of particles. The ¹³C-rich CH₄ rises along the major tectonic line or up the 50 m wide normal fault zone from relatively deep sources in the Kanto region.  相似文献   

Trans-boundary and in-country transport of air pollutants observed in Kobe,Japan by high frequent filter pack sampling method     

Masahide Aikawa  Takatoshi Hiraki  Yosuke Horie  Ryouhei Nakatsubo  Chisato Matsumura  Hitoshi Mukai 《Journal of Atmospheric Chemistry》2017,74(4):505-518

The seasonal intensive sampling of gases and particulate matter in ambient air was conducted at the site established in urban area of Japan to study the seasonal difference of the temporal variation of gases and particulate matter concentrations in urban atmosphere as well as to illustrate the different transport regimes that impacts air pollutants. The sample was collected by the four-stage filter-pack method with 6-h interval for one week in four seasons (spring, summer, autumn and winter). The trans-boundary transport of air pollutants with high concentration was characteristically observed in the spring sampling. On the other hand, we could successfully detect the in-country transports of air pollutants in the summer sampling. Four-season’s intensive survey considered, we could show the characteristic transport of air pollutants to provide the episodic high concentration for ambient air in the urban area of Japan, and successfully illustrate the seasonal-dependent transport regimes to impact on air pollutants.  相似文献