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Temperature response to future urbanization and climate change 总被引：2，自引：0，他引：2
Daniel Argüeso Jason P. Evans Lluís Fita Kathryn J. Bormann 《Climate Dynamics》2014,42(7-8):2183-2199
This study examines the impact of future urban expansion on local near-surface temperature for Sydney (Australia) using a future climate scenario (A2). The Weather Research and Forecasting model was used to simulate the present (1990–2009) and future (2040–2059) climates of the region at 2-km spatial resolution. The standard land use of the model was replaced with a more accurate dataset that covers the Sydney area. The future simulation incorporates the projected changes in the urban area of Sydney to account for the expected urban expansion. A comparison between areas with projected land use changes and their surroundings was conducted to evaluate how urbanization and global warming will act together and to ascertain their combined effect on the local climate. The analysis of the temperature changes revealed that future urbanization will strongly affect minimum temperature, whereas little impact was detected for maximum temperature. The minimum temperature changes will be noticeable throughout the year. However, during winter and spring these differences will be particularly large and the increases could be double the increase due to global warming alone at 2050. Results indicated that the changes were mostly due to increased heat capacity of urban structures and reduced evaporation in the city environment. 相似文献
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G.L. Argüello R. Dohrmann J.A. Sanabria E. Zahn 《Journal of South American Earth Sciences》2010,29(3):642-649
This paper deals with a loess profile located southeast of Córdoba (64° 05′ 30 W to 31°30′ S) that was dated in Beijing University using the OSL method according to Simple Aliquot Regeneration Protocol. This study provides some inferences regarding climatic and environmental features, such as transport agents and probable sources of the materials.The profile, located inside Llanura Pampeana, is approximately 6.80 m in depth and comprises ages between 22.4 ± 3.2 and 9.9 ± 0.3 ka. Throughout the profile, and for all grain sizes, major minerals are quartz and feldspar, with micas, and opaques as subordinates. Illite and chlorite appear as traces, though the last one was not confirmed in the finest fraction analysis. Calcite is abundant in the uppermost sample and decreases downwards. In the base of the profile, and in the clay fraction, XRD showed illite, swellable clay minerals (smectite + mixed layers) and kaolinite traces. It was concluded that the profile would have been derived from the accumulation of sediments, along several events very similar in transport conditions, even though there are some indications that about 21 ka BP, water availability was slightly smaller than for the rest of the profile. This change was also established in some other places, allowing some regional correlations. According to the analyzed data, about 19 ka BP, water availability again increased. 相似文献
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In Argentina, loess/palaeosol sequences were studied from the two sections at Monte Ralo and Corralito, located near to the city of Córdoba in the east of the Pampean ranges. Infrared optically stimulated luminescence (IRSL) and thermoluminescence (TL) dating techniques were applied to set up a more reliable chronological framework for the Upper Pleistocene loess record. IRSL ages increase with depth and are stratigraphically consistent. The oldest loess exposed correlates at least to the penultimate glaciation. The luminescence dating study gives evidence for humid climate conditions with soil formation during the last interglacial period and the middle pleniglacial correlating to Marine Isotope Stage (MIS) 5 and 3, respectively. Three extended periods of soil formation are recorded in the loess/palaeosol sequences at the Corralito section. These buried soils most likely correlate with the last interglacial and early last glacial period. During the Middle Pleniglacial, two palaeosols are intercalated in the loess successions. In the Córdoba area, the periods of increased loess accumulation and deposition of loessic sediments correlate with more arid and glacial periods during the Early Pleniglacial, the Middle Pleniglacial and the Late Glacial. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Stergios Arg. Pirintsos Luca Paoli Stefano Loppi Kiriakos Kotzabasis 《Climatic change》2011,107(3-4):305-328
A climatic change was simulated transplanting samples of the lichens Evernia prunastri (L.) Ach. and Pseudevernia furfuracea (L.) Zopf v. furfuracea along a 1,400 m altitudinal gradient in the northern side of the island of Crete (Greece). The working hypothesis was that the photosynthetic performance (i.e. pigment content, chlorophyll degradation and photosynthetic efficiency) of transplanted lichens varies along the altitudinal gradient. The overall effect observed was a general depression of the photosynthetic performance along the gradient. Concentrations of chlorophyll a, chlorophyll b and carotenoids decreased with decreasing elevation and along with the hottest and driest months of the year, with chlorophyll b being the most sensitive parameter to dry conditions. Chlorophyll degradation decreased with increasing elevation. The exposure period was the main factor affecting photosynthetic efficiency, with lower values during summer months. We argued that the water content of lichen thalli is the most important factor determining differences in photosynthesis under the experimental conditions. This allowed to suggest that the lichen photosynthetic performance deserves further investigation as early biological indicator of atmospheric stress induced by dry conditions and, to a greater extent, for the assessment of the desertification risk in the arid Mediterranean environment. 相似文献
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Robert S. French Mark R. Showalter Rafael Sfair Carlos A. Argüelles Myriam Pajuelo Patricio Becerra Matthew M. Hedman Philip D. Nicholson 《Icarus》2012,219(1):181-193
Image photometry reveals that the F ring is approximately twice as bright during the Cassini tour as it was during the Voyager flybys of 1980 and 1981. It is also three times as wide and has a higher integrated optical depth. We have performed photometric measurements of more than 4800 images of Saturn’s F ring taken over a 5-year period with Cassini’s Narrow Angle Camera. We show that the ring is not optically thin in many observing geometries and apply a photometric model based on single-scattering in the presence of shadowing and obscuration, deriving a mean effective optical depth τ ≈ 0.033. Stellar occultation data from Voyager PPS and Cassini VIMS validate both the optical depth and the width measurements. In contrast to this decades-scale change, the baseline properties of the F ring have not changed significantly from 2004 to 2009. However, we have investigated one major, bright feature that appeared in the ring in late 2006. This transient feature increased the ring’s overall mean brightness by 84% and decayed with a half-life of 91 days. 相似文献
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A. Gil de Paz J. Gallego J. Zamorano A. Alonso-Herrero A. Argón-Salamanca 《Astrophysics and Space Science》1998,261(1-4):147-150
We present results from a spectroscopic survey of Paβ & Brγ emission in a sample of T Tauri stars, mostly in the Taurus-Auriga
complex. Velocity resolved spectra (Δv ∼ 15 km s-1) show that, of the 41 stars observed in Paβ emission, 34% display IPC redshifted absorptions, while, of the 29 stars observed
in Brγ emission, 21% display IPC redshifted absorptions. The lines are broad (FWHM ∼ 200 km s-1) and lack blueshifted absorptions. These observations are consistent with the near infrared hydrogen lines forming predominantly
in infalling material, as suggested by magnetospheric accretion column models. Radiative transfer calculations of the Paβ
and Brγ line profiles in a very simplified, spherically symmetric situation are discussed.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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A. Argüelles S. A. Khainakov J. Rodríguez-Fernández M. Leoni J. A. Blanco C. Marcos 《Physics and Chemistry of Minerals》2011,38(7):569-580
Herein we report on synthetic iron-intercalated vermiculites prepared from a Mg-vermiculite mineral from Santa Olalla, Huelva, Spain, by means of an ion exchange process from aqueous solutions of FeCl2 and FeCl3. Thermogravimetric, X-ray diffraction, magnetic susceptibility and Mössbauer spectral studies have been used to characterize the synthetic iron-intercalated vermiculites. The results suggest that the intercalation process employed induces modifications in both the interlayer spacing and in the octahedral sheet; the disordered structure of the Mg-vermiculite mineral is not altered. The presence of solvated Fe(H2O) n 2+ ions has been shown by the Mössbauer spectroscopy. No magnetic order has been observed between 2 and 300 K neither in the Mg-vermiculite mineral nor in the two synthetic iron-intercalated vermiculites. 相似文献