HS 1216+5032: a physical quasar pair with one radio-loud broad absorption line quasar     

P. J. Green  Thomas L. Aldcroft  Warren R. Brown  Olga Kuhn  Abhijit Saha 《Monthly notices of the Royal Astronomical Society》2004,349(4):1261-1266

  相似文献   

Lessons from JI and GIS for post-2012 carbon finance mechanisms in Russia and Ukraine     

Anna Korppoo  Olga Gassan-Zade 《Climate Policy》2013,13(2):224-241

The main incentives for Russia's and Ukraine's participation in the first commitment period of the Kyoto Protocol were its mechanisms. The opportunities that the anticipated post-2012 mechanisms will offer Russia and Ukraine are explored in light of the lessons from Joint Implementation (JI) and the Green Investment Scheme (GIS) during this first period. Four key factors that explain the success of these mechanisms are identified: the design of the mechanisms, the role of the private sector in their implementation, the coordination required, and the political will gained. Even though a weak rule of law, problems with policy implementation, and the ambiguous role of private-sector actors are not ‘make or break’ issues, they are likely to defer future mechanisms. Success and failure will, rather, hinge on the priority these factors are accorded by the top leadership. It is likely that simple mechanisms that only involve a few actors will be less complicated to set up and run than, for instance, emissions trading schemes (which require domestic burden sharing). Project-based options in which domestic actors have gained experience may be better suited. However, any lessons prior to the new mechanisms taking a clearer shape must be considered as preliminary.

Policy relevance

The Kyoto Protocol mechanisms, despite their problems, provided Russia and Ukraine with their main incentives for participation in the Protocol's first commitment period. As the chances that these countries will participate in the second commitment period seem slim, the opportunities that the anticipated post-2012 mechanisms will offer Russia and Ukraine are explored in light of the lessons from JI and GIS. The key factors that have determined the success and failure of these mechanisms are likely to be of relevance to future mechanisms. It is argued that – of the post-2012 options available – simple mechanisms with few actors involved should be chosen. Project-based options rather than emissions trading schemes may be more likely to succeed due to experience gained by domestic actors.  相似文献   

Observations and Analysis of the Non-Radial Propagation of Coronal Mass Ejections Near the Sun     

Paulett Liewer  Olga Panasenco  Angelos Vourlidas  Robin Colaninno 《Solar physics》2015,290(11):3343-3364

  相似文献   

Lichenometry in the Cordillera Blanca, Peru: “Little Ice Age” moraine chronology   总被引：1，自引：1，他引：0  

Olga Solomina  Vincent Jomelli  Georg Kaser  Alcides Ames  Bernhard Berger  Bernard Pouyaud 《Global and Planetary Change》2007,59(1-4):225

This paper is a comparison and compilation of lichenometric and geomorphic studies performed by two independent teams in the Cordillera Blanca, Peru, in 1996 and 2002 on 66 “Little Ice Age” moraines of 14 glaciers. Using eleven new control points, we recalibrated the initial rapid growth phase of the previously established Rhizocarpon subgenus Rhizocarpon growth curve. This curve was then used to estimate the age of “Little Ice Age” moraines. The time of deposition of the most prominent and numerous terminal and lateral moraines on the Pacific-facing side of the Cordillera Blanca (between AD 1590 and AD 1720) corresponds to the coldest and wettest phase in the tropical Andes as revealed by ice-core data. Less prominent advances occurred between AD 1780 and 1880.  相似文献   

The Source Regions of Impulsive Solar Electron Events   总被引：1，自引：0，他引：1  

Benz  Arnold O.  Lin  Robert P.  Sheiner  Olga A.  Krucker  Säm  Fainberg  Joe 《Solar physics》2001,203(1):131-144

Low-energy (2–19 keV) impulsive electron events observed in interplanetary space have been traced back to the Sun, using their interplanetary type III radiation and metric/decimetric radio-spectrograms. For the first time we are able to study the highest frequencies and thus the radio signatures closest to the source region. All the selected impulsive solar electron events have been found to be associated with an interplanetary type III burst. This allows to time the particle events at the 2 MHz plasma level and identify the associated coronal radio emissions. Except for 5 out of 27 cases, the electron events were found to be associated with a coronal type III burst in the metric wavelength range. The start frequency yields a lower limit to the density in the acceleration region. We also search for narrow-band spikes at the start of the type III bursts. In about half of the observed cases we find metric spikes or enhancements of type I bursts associated with the start of the electron event. If interpreted as the plasma emission of the acceleration process, the observed average frequency of spikes suggests a source density of the order of 3×10⁸ cm^–3 consistent with the energy cut-off observed.  相似文献   

Mirror instability upstream of the termination shock (TS) and in the heliosheath   总被引：1，自引：0，他引：1  

Bruce T. Tsurutani  Ezequiel Echer  Olga P. Verkhoglyadova  Gurbax S. Lakhina  F.L. Guarnieri 《Journal of Atmospheric and Solar》2011,73(11-12):1398-1404

We experimentally identify mirror mode (MM) structures in the Voyager 1 heliosheath data for the first time. This is done using the magnetic field data alone. The heliosheath MM structures are found to have the following characteristics: (1) quasiperiodic spacings with a typical scale size of ～57 ρ_p, (2) little or no angular changes across the structures (～3° longitude and ～3° latitude), and (3) a lack of sharp boundaries at the magnetic dip edges. It is demonstrated that the pickup of interstellar neutrals in the upstream region of the termination shock (TS) and quasiperpendicular TS plasma compression are the causes of MM instability during intervals when the IMF is nearly orthogonal to the solar wind flow direction. Concomitant additional injection of pickup ions (PUIs) throughout the heliosheath will lead to further MM amplification. MM structures in planetary magnetosheaths and interplanetary sheaths are discussed for comparative purposes. Multiple sources of free energy are often involved.  相似文献   

Petrogenesis of Na-rich paralava formed by methane flares associated with mud volcanism, Altyn-Emel National Park, Kazakhstan     

Rodney Grapes  Ella Sokol  Svetlana Kokh  Olga Kozmenko  Ilia Fishman 《Contributions to Mineralogy and Petrology》2013,165(4):781-803

High-Na slag-like rocks (paralava) with 4.5–11 % Na₂O from the Altyn-Emel mud volcanic field, Kazakhstan, are the products of melting of sediment + salt mixtures by methane flares associated with mud extrusion. The main minerals of the paralavas are diopside and wollastonite which have quench morphologies. Other high-temperature phases (crystallizing from melt and vapour phase) are tridymite, cristobalite, chlorapatite, alkali feldspar, pyrrhotite, native iron and silicon, iron phosphides, titanite, rutile, and carbon. The paralavas lack the Na–Ca silicates devitrite and combeite, but have high-Na and Na–K glasses that have not been homogenized despite low viscosities of <10^?3.5 Pa s. The large number of ignition foci in the Altyn-Emel mud volcano field indicates gas venting from small, shallow reservoirs. The methane flares are inferred to have been small and the fire events short-lived. Fires were extinguished once overpressure released during eruption, methane venting stopped and melted rocks rapidly quenched. The periodicity of eruptions and methane flaring most likely depends on the recurrence of earthquakes (M < 5) which are frequent in this tectonically active area.  相似文献   

Initial Fe/O Enhancements in Large, Gradual, Solar Energetic Particle Events: Observations from Wind and Ulysses     

Allan J. Tylka  Olga E. Malandraki  Gareth Dorrian  Yuan-Kuen Ko  Richard G. Marsden  Chee K. Ng  Cecil Tranquille 《Solar physics》2013,285(1-2):251-267

Shocks driven by fast coronal mass ejections (CMEs) are the dominant particle accelerators in large, “gradual” solar energetic particle (SEP) events. In these events, the event-integrated value of the iron-to-oxygen ratio (Fe/O) is typically ～?0.1, at least at energies of a few MeV/nucleon. However, at the start of some gradual events, when intensities are low and growing, initially Fe/O is ～?1. This value is also characteristic of small, “impulsive” SEP events, in which particle acceleration is due to magnetic reconnection. These observations suggested that SEPs in gradual events also include a direct contribution from the flare that accompanied the CME launch. If correct, this interpretation is of critical importance: it indicates a clear path to interplanetary space for particles from the reconnection region beneath the CME. A key issue for the flare origin is “magnetic connectedness”, i.e., proximity of the flare site to the solar footpoint of the observer’s magnetic field line. We present two large gradual events observed in 2001 by Wind at L1 and by Ulysses, when it was located at >?60^° heliolatitude and beyond 1.6 AU. In these events, transient Fe/O enhancements at 5?–?10 MeV/nucleon were seen at both spacecraft, even though one or both is not “well-connected” to the flare. These observations demonstrate that an initial Fe/O enhancement cannot be cited as evidence for a direct flare component. Instead, initial Fe/O enhancements are better understood as a transport effect, driven by the different mass-to-charge ratios of Fe and O. We further demonstrate that the time-constant of the roughly exponential decay of the Fe/O ratio scales as R ², where R is the observer’s radial distance from the Sun. This behavior is consistent with radial diffusion. These observations thus also provide a potential constraint on models in which SEPs reach high heliolatitudes by cross-field diffusion.  相似文献   

Magnetic Flux Changes and Cancellation Associated with X-Class and M-Class Flares     

Olga Burtseva  Gordon Petrie 《Solar physics》2013,283(2):429-452

We perform a statistical study of permanent changes in longitudinal fields associated with solar flares by tracking magnetic features. The YAFTA feature tracking algorithm is applied to GONG++ 1-minute magnetograms for 77 X-class and M-class flares to analyze the evolution and interaction of the magnetic features and to estimate the amount of canceled magnetic flux. We find that significantly more magnetic flux decreases than increases occurred during the flares, consistent with a model of collapsing loop structure for flares. Correlations between both total (unsigned) and net (signed) flux changes and the GOES peak X-ray flux are dominated by X-class flares at limb locations. The flux changes were accompanied in most cases by significant cancellation, most of which occurred during the flares. We find that the field strength and complexity near the polarity inversion line are approximately equally important in the flux cancellation processes that accompany the flares. We do not find a correlation between the flux cancellation events and the stepwise changes in the magnetic flux in the region.  相似文献   

Identifying factors of influence in the spatial distribution of domestic fires     

Olga Špatenková  Alfred Stein 《International journal of geographical information science》2013,27(6):841-858

Domestic fires at the city level, being causes for casualties and causing significant material damages, are stored as a point pattern in a GIS. In this paper we apply a statistical point pattern analysis to derive major causes from related layers of information. We fit a G-function to analyse neighbourhood relations and a Strauss process for inferring causal relations. Using open-source software we find significant differences in patterns and explaining factors between the different parts of the day, in particular for different building types and income groups. We conclude that a quantitative spatial model can be fitted and that this provides a useful opportunity for fire brigades to improve planning their efforts.  相似文献