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51.
52.
High resolution regional climate model simulations for Germany: Part II—projected climate changes 总被引:1,自引:1,他引:0
The projected climate change signals of a five-member high resolution ensemble, based on two global climate models (GCMs: ECHAM5 and CCCma3) and two regional climate models (RCMs: CLM and WRF) are analysed in this paper (Part II of a two part paper). In Part I the performance of the models for the control period are presented. The RCMs use a two nest procedure over Europe and Germany with a final spatial resolution of 7 km to downscale the GCM simulations for the present (1971–2000) and future A1B scenario (2021–2050) time periods. The ensemble was extended by earlier simulations with the RCM REMO (driven by ECHAM5, two realisations) at a slightly coarser resolution. The climate change signals are evaluated and tested for significance for mean values and the seasonal cycles of temperature and precipitation, as well as for the intensity distribution of precipitation and the numbers of dry days and dry periods. All GCMs project a significant warming over Europe on seasonal and annual scales and the projected warming of the GCMs is retained in both nests of the RCMs, however, with added small variations. The mean warming over Germany of all ensemble members for the fine nest is in the range of 0.8 and 1.3 K with an average of 1.1 K. For mean annual precipitation the climate change signal varies in the range of ?2 to 9 % over Germany within the ensemble. Changes in the number of wet days are projected in the range of ±4 % on the annual scale for the future time period. For the probability distribution of precipitation intensity, a decrease of lower intensities and an increase of moderate and higher intensities is projected by most ensemble members. For the mean values, the results indicate that the projected temperature change signal is caused mainly by the GCM and its initial condition (realisation), with little impact from the RCM. For precipitation, in addition, the RCM affects the climate change signal significantly. 相似文献
53.
Emily Tyler Anya Boyd Kim Coetzee Marta Torres Gunfaus Harald Winkler 《Climate Policy》2013,13(6):770-776
The MAPS programme, which seeks to deepen mitigation ambition in developing countries, is engaged in exploring the concepts of Nationally Appropriate Mitigation Actions (NAMAs) and Low Carbon Development Strategies (LCDS) from a developing country perspective. Here, climate mitigation practitioners in six developing countries were surveyed for their understanding of these concepts (anonymous, personal communications with climate mitigation practitioners in Argentina, Brazil, Chile, Colombia, India, and South Africa). It is found that there is much scope for clarity and conceptual elaboration in this policy space. NAMAs are largely interpreted as mitigation activities packaged for submission to the United Nations Framework Convention on Climate Change (UNFCCC) registry, but are not held to constitute the full set of mitigation activity in a developing country. New terminology may be needed to describe this broader set. A tighter interpretation of LCDS to distinguish between a strategic or coordinating policy action may be useful. Other themes arising include the way ‘national appropriateness’ is reflected in the concepts, and the role of international policy in deepening mitigation action in developing countries. 相似文献
54.
It is shown that there are MRV-related activities underway in South Africa, particularly focusing on measuring electricity consumption and monitoring GHG emissions. Yet currently many of these activities happen in parallel systems within multi-polar governance structures. A bottom-up perspective of MRV in South Africa, informed by interviews, workshops, desktop research, and stakeholder consultations, is provided and the systems, data, methodologies, and the institutional environment relevant to a South African MRV system are examined. The development of the local monitoring and evaluation system, and its relevance within the international MRV context, is also discussed. Some recommendations are made: most importantly, there is a need for a coherent approach to be developed, one that is coordinated by government and built on existing MRV systems. 相似文献
55.
Mark A. Norris Ray M. Sharples Harald Kuntschner 《Monthly notices of the Royal Astronomical Society》2006,367(2):815-824
We present Gemini Multi-Object Spectrograph longslit spectroscopy of the isolated S0 galaxy NGC 3115. We have determined kinematical data and Lick/IDS absorption line-strength indices for the major axis out to around 9 kpc and for the minor axis out to around 5 kpc (around 2R e ). Using stellar population models which include the effects of variable [α/Fe] ratios, we derive metallicities, abundance ratios and ages for the stellar population of NGC 3115. We find that [α/Fe] remains fairly constant with increasing radius at around [α/Fe]= 0.17 for the major axis but increases rapidly for the minor axis to around [α/Fe]= 0.3 . We also find that to first order, this behaviour can be explained by a simple spheroid + disc model, where the spheroid has [α/Fe]= 0.3 and the disc shows close to solar abundance ratios. The disc also appears considerably younger than the spheroid, having an age of around 6 Gyr compared to 12 Gyr for the spheroid. We compare these results to those previously presented for the globular cluster system of NGC 3115. 相似文献
56.
Michael B. Pracy Warrick J. Couch Chris Blake Kenji Bekki Craig Harrison Matthew Colless Harald Kuntschner Roberto de Propris 《Monthly notices of the Royal Astronomical Society》2005,359(4):1421-1432
We present spatially resolved intermediate-resolution spectroscopy of a sample of 12 E+A galaxies in the z = 0.32 rich galaxy cluster AC 114, obtained with the FLAMES multi-integral field unit system on the Very Large Telescope (VLT) of the European Southern Observatory. Previous integrated spectroscopy of all these galaxies by Couch & Sharples had shown them to have strong Balmer line absorption and an absence of [O ii ]λ3727 emission – the defining characteristics of the 'E+A' spectral signature, indicative of an abrupt halt to a recent episode of quite vigorous star formation. We have used our spectral data to determine the radial variation in the strength of Hδ absorption in these galaxies and hence map out the distribution of this recently formed stellar population. Such information provides important clues as to what physical event might have been responsible for this quite dramatic change in star formation activity in the recent past of these galaxies. We find a diversity of behaviour amongst these galaxies in terms of the radial variation in Hδ absorption: four galaxies show little Hδ absorption across their entire extent; it would appear they were misidentified as E+A galaxies in the earlier integrated spectroscopic studies. The remainder show strong Hδ absorption, with a gradient that is either negative (Hδ equivalent width decreasing with radius), flat or positive . By comparison with numerical simulations we suggest that the first of these different types of radial behaviour provides evidence for a merger/interaction origin, whereas the latter two types of behaviour are more consistent with the truncation of star formation in normal disc galaxies with the Hδ gradient becoming increasingly positive with time after truncation. It would seem therefore that more than one physical mechanism is responsible for E+A formation in the same environment. 相似文献
57.
58.
59.
Niranjan Thatte Reinhard Genzel Harald Kroker Alfred Krabbe Lowell E. Tacconi-Garman Roberto Maiolino Matthias Tecza 《Astrophysics and Space Science》1997,248(1-2):225-234
We present new near-infrared integral field spectroscopy and adaptive optics imaging of the nucleus of NGC 1068. Using the
stellar CO absorption features in the H and K bands, we have identified a moderately extincted stellar core centered on the
nuclear position and of intrinsic size ~50 pc. We show that this nuclear stellar core is probably 5-16 × 108 years in age
and contributes at least 7% of the total nuclear luminosity of ~1 × 1011 L⊙.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
60.
A total of 150 samples were collected at a 10-days' anchor station in the Bornholm basin (55° 31.1′N, 15° 32.1′E) and analyzed for dissolved (< 0.4 μm) and particulate trace metals. For dissolved Mn, large gradients have been found in the vertical distribution with minimum concentrations (< 0.2 μgl?1) in the halocline zone and considerably higher values in the deep waters (up to 50 μgl?1). Ultrafiltration studies indicate that dissolved Mn is probably present as Mn2+ in the oxygenated bottom layer. The primary production process was not evident in the particulate Mn profile; the suspended particulate material (SPM), however, shows a considerable enrichment with depth, apparently due to Mn-oxide precipitation.The distribution of dissolved Fe was rather homogeneous, with average concentrations throughout the water column between 0.86 and 1.1 μgl?1, indicating that the oxidation of Fe2+ ions released from the sediments must already be complete in the very near oxidation boundary layer. Relatively high concentrations of particulate Fe were actually measured in the bottom layer, with the maximum mean of 11.2 μgl?1 at 72 m. Similarly to Mn, the profile of particulate Fe does not reflect the SPM curve of the eutrophic layer. On average, about 70% of the total Fe in surface waters was found to be particulate.The average concentrations of dissolved Zn, Cd and Cu were found to be rather homogeneous in the water column but showed a relatively high variability with time. A simplified model on trace-metal uptake by phytoplankton indicates no significant change in dissolved metal concentrations during the period of investigation. On average, only 1.7% Zn, 3.3% Cd and 9.8% Cu of the total metal concentrations were found in particulate form. SPM analyses showed significant correlations of Zn, Cd and Cu with Fe, indicating that particulate iron is an important carrier for particulate trace metals in Baltic waters. 相似文献