Climate change,income and happiness: An empirical study for Barcelona   总被引：1，自引：0，他引：1  

Filka Sekulova  Jeroen C.J.M. van den Bergh 《Global Environmental Change》2013,23(6):1467-1475

The present article builds upon the results of an empirical study exploring key factors which determine life satisfaction in Barcelona. Based on a sample of 840 individuals we first look at the way changes in income, notably income reductions, associated with the current economic situation in Spain, affect subjective well-being. Income decreases which occur with respect to one year ago have a negative effect on happiness when specified in logarithmic terms, and a positive one when specified as a dummy variable (and percentage change). The divergence in results is discussed and various explanations are put forward. Both effects are however temporary and do not hold for a period longer than a year, probably for reasons of adaptation and a downward adjustment of reference consumption and income levels. Next, we examine the implications of experiencing forest fires and find a lasting negative effect on life satisfaction. Our results suggest that climate policy need not reduce happiness in the long run, even when it reduces income and carbon-intensive consumption. Climate policy may even raise life well-being, if accompanied by compensatory measures that decrease formal working hours and reference consumption standards, while maintaining employment security.  相似文献   

The abundance and radial distribution of satellite galaxies     

Frank C. van den Bosch  Xiaohu Yang  H. J. Mo  Peder Norberg 《Monthly notices of the Royal Astronomical Society》2005,356(4):1233-1248

Using detailed mock galaxy redshift surveys (MGRSs) we investigate the abundance and radial distribution of satellite galaxies. The mock surveys are constructed using large numerical simulations and the conditional luminosity function (CLF), and are compared against data from the Two Degree Field Galaxy Redshift Survey (2dFGRS). We use Monte Carlo Markov chains to explore the full posterior distribution of the CLF parameter space, and show that the average relation between light and mass is tightly constrained and in excellent agreement with our previous models and with that of Vale & Ostriker. The radial number density distribution of satellite galaxies in the 2dFGRS reveals a pronounced absence of satellites at small projected separations from their host galaxies. This is (at least partly) owing to the overlap and merging of galaxy images in the 2dFGRS parent catalogue. Owing to the resulting close-pair incompleteness we are unfortunately unable to put meaningful constraints on the radial distribution of satellite galaxies; the data are consistent with a radial number density distribution that follows that of the dark matter particles, but we cannot rule out alternatives with a constant number density core. Marginalizing over the full CLF parameter space, we show that in a ΛCDM concordance cosmology the observed abundances of host and satellite galaxies in the 2dFGRS indicate a power spectrum normalization of  σ₈≃ 0.7  . The same cosmology but with  σ₈= 0.9  is unable to match simultaneously the abundances of host and satellite galaxies. This confirms our previous conclusions based on the pairwise peculiar velocity dispersions and the group multiplicity function.  相似文献   

Pre-heating by pre-virialization and its impact on galaxy formation     

H. J. Mo  Xiaohu Yang  Frank C. van den Bosch  Neal Katz 《Monthly notices of the Royal Astronomical Society》2005,363(4):1155-1166

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The angular momentum content of dwarf galaxies: new challenges for the theory of galaxy formation     

Frank C. van den Bosch  reas Burkert  Rob A. Swaters 《Monthly notices of the Royal Astronomical Society》2001,326(3):1205-1215

We compute the specific angular momentum distributions for a sample of low-mass disc galaxies observed by Swaters. We compare these distributions to those of dark matter haloes obtained by Bullock et al. from high-resolution N -body simulations of structure formation in a ΛCDM universe. We find that although the disc mass fractions are significantly smaller than the universal baryon fraction, the total specific angular momenta of the discs are in good agreement with those of dark matter haloes. This suggests that discs form out of only a small fraction of the available baryons, but yet manage to draw most of the available angular momentum. In addition we find that the angular momentum distributions of discs are clearly distinct from those of the dark matter; discs lack predominantly both low and high specific angular momenta. Understanding these findings in terms of a coherent picture for disc formation is challenging. Cooling, feedback and stripping, which are the main mechanisms to explain the small disc mass fractions found, seem unable to simultaneously explain the angular momentum distributions of the discs. In fact, it seems that the baryons that make up the discs must have been born out of angular momentum distributions that are clearly distinct from those of ΛCDM haloes. However, the dark and baryonic mass components experience the same tidal forces, and it is therefore expected that they should have similar angular momentum distributions. Therefore, understanding the angular momentum content of disc galaxies remains an important challenge for our picture of galaxy formation.  相似文献   

Short time-scale variability in the Faint Sky Variability Survey     

L. Morales-Rueda  P. J. Groot  T. Augusteijn  G. Nelemans  P. M. Vreeswijk  E. J. M. van den Besselaar 《Monthly notices of the Royal Astronomical Society》2006,371(4):1681-1692

We present the V -band variability analysis of the point sources in the Faint Sky Variability Survey on time-scales from 24 min to tens of days. We find that about one per cent of the point sources down to   V = 24  are variables. We discuss the variability-detection probabilities for each field depending on field sampling, amplitude and time-scale of the variability. The combination of colour and variability information allows us to explore the fraction of variable sources for different spectral types. We find that about 50 per cent of the variables show variability time-scales shorter than 6 h. The total number of variables is dominated by main-sequence sources. The distribution of variables with spectral type is fairly constant along the main sequence, with 1 per cent of the sources being variable, except at the blue end of the main sequence, between spectral types F0 and F5, where the fraction of variable sources increases to about 2 per cent. For bluer sources, above the main sequence, this percentage increases to about 3.5. We find that the combination of the sampling and the number of observations allows us to determine the variability time-scales and amplitudes for a maximum of 40 per cent of the variables found. About a third of the total number of short time-scale variables found in the survey were not detected in either B or/and I band. These show a similar variability time-scale distribution to that found for the variables detected in all three bands.  相似文献   

A hybrid solution for wave propagation problems in regular media with bounded irregular inclusions     

A. P. van den  Berg 《Geophysical Journal International》1984,79(1):3-10

Summary. This paper describes a method that enables one to calculate the effects of localized heterogeneities on the wavefield in an otherwise regular medium. It does so by connecting a finite element solution for a heterogeneous inclusion to any type of solution for the regular medium, e.g. a reflectivity solution for a layered medium or an analytical solution for a simple half-space. Once the Green's functions for the regular medium are determined, the method reduces to a coupled set of algebraic equations for the wavefield, with the incident field and/or body forces as known variables. An efficient numerical scheme is derived for the solution of these equations.  相似文献   

The origin of cosmic gamma-ray bursts     

Sidney van den Bergh 《Astrophysics and Space Science》1983,97(2):385-388

The positions of 46 γ-ray burst sources on the sky are used to show that the majority of these objects either originate in very distant regions with redshifts ?30000 km s^?1 or within ?0.5β of the Sun; where β is the scale-height of the parent population perpendicular to the galactic disc. An origin of the majority of γ-ray bursts in the more distant parts of the galactic disc, the galactic nuclear bulge, the Virgo supercluster, in galaxies withm _pg<18 and rich in Abell clusters of distance classes 0 to 4 is excluded by the data.  相似文献   

The Summer Surface Energy Balance of the High Antarctic Plateau   总被引：1，自引：0，他引：1  

Dirk?van?AsEmail author  Michiel?van?den?Broeke  Carleen?Reijmer  Roderik?van?de?Wal 《Boundary-Layer Meteorology》2005,115(2):289-317

The summertime surface energy balance (SEB) at Kohnen station, situated on the high Antarctic plateau (75°00′ S, 0°04′ E, 2892m above sea level) is presented for the period of 8 January to 9 February 2002. Shortwave and longwave radiation fluxes were measured directly; the former was corrected for problems associated with the cosine response of the instrument. Sensible and latent heat fluxes were calculated using the bulk method, and eddy-correlation measurements and the modified Bowen ratio method were used to verify these calculated fluxes. The calculated sub-surface heat flux was checked by comparing calculated to measured snow temperatures. Uncertainties in the measurements and energy-balance calculations are discussed. The general meteorological conditions were not extraordinary during the period of the experiment, with a mean 2-m air temperature of −27.5°C, specific humidity of 0.52×10⁻³kg kg⁻¹ and wind speed of 4.1ms⁻¹. The experiment covered the transition period from Antarctic summer (positive net radiation) to winter (negative net radiation), and as a result the period mean net radiation, sensible heat, latent heat and sub-surface heat fluxes were small with values of −1.1, 0.0, −1.0 and 0.7 Wm⁻², respectively. Daily mean net radiation peaked on cloudy days (16 Wm⁻²) and was negative on clear-sky days (minimum of −19 W m⁻²). Daily mean sensible heat flux ranged from −8 to +10 Wm⁻², latent heat flux from −4 to 0 Wm⁻² and sub-surface heat flux from −8 to +7 Wm⁻².  相似文献   

Models for the formation of binary and millisecond radio pulsars     

Edward P. J. Van den Heuvel 《Journal of Astrophysics and Astronomy》1984,5(3):209-233

The peculiar combination of a relatively short pulse period and a relatively weak surface dipole magnetic field strength of binary radio pulsars finds a consistent explanation in terms of (i) decay of the surface dipole component of neutron-star magnetic fields on a timescale of (2–5) × 10⁶ yr, in combination with (ii) spin-up of the rotation of the neutron star during a subsequent mass-transfer phase. The four known binary radio pulsars appear to fall into two different categories. Two of them, PSR 0655 + 64 and PSR 1913 + 16, have short orbital periods (<25 h) and high mass functions, indicating companion masses 0.7M⊙ (∼1 (± 0.3) M⊙ and 1.4 M⊙, respectively). The other two, PSR 0820 + 02 and PSR 1953 + 29, have long orbital periods (117d), nearly circular orbits, and low, almost identical mass functions of about 3×10^-3 M⊙, suggesting companion masses of about 0.3M⊙. It is pointed out that these two classes of systems are expected to be formed by the later evolution of binaries consisting of a neutron star and a normal companion star, in which the companion was (considerably) more massive than the neutron star, or less massive than the neutron star, respectively. In the first case the companion of the neutron star in the final system will be a massive white dwarf, in a circular orbit, or a neutron star in an eccentric orbit. In the second case the final companion to the neutron star will be a low-mass (∼ 0.3 M⊙) helium white dwarf in a wide and nearly circular orbit. In systems of the second type the neutron star was most probably formed by the accretion-induced collapse of a white dwarf. This explains in a natural way why PSR 1953 + 29 has a millisecond rotation period and PSR 0820 + 02 has not. Among the binary models proposed for the formation of the 1.5-millisecond pulsar, the only ones that appear to be viable are those in which the companion disappeared by coalescence with the neutron star. In such models the companion may have been a red dwarf of mass 0.03M⊙, a neutron star, or a massive (>0.7M⊙) white dwarf. Only in the last-mentioned case is a position of the pulsar close to the galactic plane a natural consequence. In the first-mentioned case the progenitor system most probably was a cataclysmic-variable binary in which the white dwarf collapsed by accretion.  相似文献   

Spatially-Averaged Temperature Structure Parameter Over a Heterogeneous Surface Measured by an Unmanned Aerial Vehicle   总被引：1，自引：1，他引：0  

A. C. van den Kroonenberg  S. Martin  F. Beyrich  J. Bange 《Boundary-Layer Meteorology》2012,142(1):55-77

The structure parameter of temperature, \({C_{T}^{2}}\) , in the lower convective boundary layer was measured using the unmanned mini aerial vehicle M²AV. The measurements were carried out on two hot summer days in July 2010 over a heterogeneous land surface around the boundary-layer field site of the Lindenberg Meteorological Observatory—Richard-Aßmann-Observatory of the German Meteorological Service. The spatial series of \({C_{T}^{2}}\) showed considerable variability along the flight path that was caused by both temporal variations and surface heterogeneity. Comparison of the aircraft data with \({C_{T}^{2}}\) values derived from tower-based in situ turbulence measurements showed good agreement with respect to the diurnal variability. The decrease of \({C_{T}^{2}}\) with height as predicted by free-convection scaling could be confirmed for the morning and afternoon flights while the flights around noon suggest a different behaviour.  相似文献