On bandwidth selection for nonparametric estimation in flood frequency analysis     

A. Quintela‐del‐Río 《水文研究》2011,25(5):671-678

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Observations of a Radio-Quiet Solar Preflare     

Arnold O. Benz  Marina Battaglia  Manuel Güdel 《Solar physics》2017,292(10):151

The preflare phase of the flare SOL2011-08-09T03:52 is unique in its long duration, in that it was covered by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Nobeyama Radioheliograph, and because it showed three well-developed soft X-ray (SXR) peaks. No hard X-rays (HXR) are observed in the preflare phase. Here we report that no associated radio emission at 17 GHz was found either, despite the higher sensitivity of the radio instrument. The ratio between the SXR peaks and the upper limit of the radio peaks is higher by more than one order of magnitude than the ratio in regular flares. The result suggests that the ratio between acceleration and heating in the preflare phase was different than in regular flares. Acceleration to relativistic energies, if any, occurred with lower efficiency.  相似文献   

Jurassic‐to‐present thermal history of the central High Atlas (Morocco) assessed by low‐temperature thermochronology     

Luis Barbero  Antonio Teixell  María‐Luisa Arboleya  Pedro del Río  Peter W. Reiners  Blaid Bougadir 《地学学报》2007,19(1):58-64

Apatite fission track (AFT) and (U–Th)/He data from the High Atlas have been obtained for the first time to constrain the tectono‐thermal evolution of the central part of the chain. Results from Palaeozoic basement massifs indicate long residence at low temperatures, consistently with their original location out of the deepest Mesozoic rift troughs and indicating minor exhumation. The best rocks for extracting the Alpine history of the Atlas Mountains are Jurassic intrusives, which yield AFT ages centred on c. 80 Ma; thermal models based on AFT data and constrained by (U–Th)/He suggest that these ages are included in a slow cooling trend from intrusion age to c. 50 Ma ago that we attribute to post‐rift thermal relaxation. This is followed by a stability period of c. 30 Ma and then by a final exhumational cooling until present exposure. Eocene intrusives yield AFT ages similar to those of Rb–Sr and K–Ar suggesting rapid emplacement in the uppermost crust.  相似文献   

Properties of dust and detection of Hα emission in LDN 1780     

C. del Burgo  L. Cambrésy 《Monthly notices of the Royal Astronomical Society》2006,368(3):1463-1478

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Factors affecting wave magnitude and period during the earthquakes of September, 1985     

Enrique del Valle Toledo 《Geotechnical and Geological Engineering》1989,7(1):29-35

Summary The geology and structure of the Mexico Basin are discussed and hypotheses developed to explain the magnification of wave amplitudes during the 1985 earthquake.  相似文献   

Relationships between Holocene sea-level variations,trophic development,and climatic change in Negra Lagoon,Southern Uruguay     

R.?Bracco  H.?Inda  L.?del Puerto  C.?Casti?eira  P.?Sprechmann  F.?García-RodríguezEmail author 《Journal of Paleolimnology》2005,33(3):253-263

Paleolimnological data are presented on trophic development, climatic change and sea level variations in Negra Lagoon, a 142 km² coastal lagoon in southern Uruguay. Using a sediment core that extended to the early Holocene, analyses of organic matter, carbonate, diatoms and opal phytoliths allowed us to track changes in trophic state and paleosalinity levels, which were closely related to Holocene sea level variation, temperature and humidity. Diatom Association Zones (DAZ) corresponding to transgressive events were dominated by marine/brackish taxa and relatively low organic matter values, while those DAZ corresponding to regressive events showed increases in brackish/freshwater diatoms and organic matter. Opal Phytoliths Association Zones (OPAZ) also were identified, temperature and humidity indices were calculated, and climatic trends were inferred. During the middle Holocene (i.e., ~5000–4000 yr BP), cool–dry climatic conditions were established. After ~4000 yr BP, a transition from cool to warm–humid conditions was observed, but fully warm humid conditions established only after ~1700 yr BP. Such climatic amelioration led to increases in trophic state.  相似文献   

Recent trends in mean maximum and minimum air temperatures over Spain (1961–2006)     

S. del Río  A. Cano-Ortiz  L. Herrero  A. Penas 《Theoretical and Applied Climatology》2012,109(3-4):605-626

This study analyzes the mean maximum and minimum temperature trends on a monthly, seasonal, and annual timescale by applying various statistical tools to data from 476 Spanish weather stations during the period between 1961 and 2006. The magnitude of the trends was derived from the slopes of the regression lines using the least squares method, and the nonparametric Mann–Kendall test was used to determine the statistical significance of the trends. Temperature significantly increased in over 60% of the country in March, June, spring, and summer in the case of maximum temperatures and in March, May, June, August, spring, and summer for minimum temperatures. At the annual resolution, temperatures significantly increased in over 90% of Spain with a rise of around 0.3°C/decade. The maximum temperature increased at a higher rate than the minimum temperature from midsummer to early winter as well as in winter, spring, and summer and also on an annual basis.  相似文献   

The western Mediterranean climate: how will it respond to global warming?     

Dario Camuffo  C. Bertolin  N. Diodato  M. Barriendos  F. Dominguez-Castro  C. Cocheo  A. della Valle  E. Garnier  M. -J. Alcoforado 《Climatic change》2010,100(1):137-142

The paper discusses the newly produced temperature and precipitation series from instrumental observations in the Western Mediterranean (WM) area, dating back to 1654. The two series had a continuous swing and unstable coupling passing from correlation to anti-correlation. Only after 1950 are they permanently anti-correlated with increasing temperature and decreasing precipitation. It is not clear how long this coupling will persist. The analysis of the correlation between the Northern Hemisphere (NH) and the WM temperature anomalies and their trends shows a certain variability from 1850 to 1950; later a strong coupling between NH and WM. Results suggest that the WM climate is approaching a turning point that might locally oppose the adverse effects of Global Warming.  相似文献   

Cloud structure of Saturn’s 2010 storm from ground-based visual imaging     

J.F. Sanz-Requena  S. Pérez-Hoyos  A. Sánchez-Lavega  T. del Río-Gaztelurrutia  D. Barrado-Navascués  F. Colas  J. Lecacheux  D. Parker 《Icarus》2012,219(1):142-149

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X‐rays from young stars: A summary of highlights from the XMM‐Newton Extended Survey of the Taurus Molecular Cloud (XEST)     

M. Güdel 《Astronomische Nachrichten》2008,329(2):218-221

The XMM‐Newton Extended Survey of the Taurus Molecular Cloud (XEST) is a survey of the nearest large star‐forming region, the Taurus Molecular Cloud (TMC), making use of all instruments on board the XMM‐Newton X‐ray observatory. The survey, presently still growing, has provided unprecedented spectroscopic results from nearly every observed T Tauri star, and from ≈50% of the studied brown dwarfs and protostars. The survey includes the first coherent statistical sample of high‐resolution spectra of T Tauri stars, and is accompanied by an U ‐band/ultraviolet imaging photometric survey of the TMC. XEST led to the discovery of new, systematic X‐ray features not possible before with smaller samples, in particular the X‐ray soft excess in classical T Tauri stars and the Two‐Absorber X‐ray (TAX) spectra of jet‐driving T Tauri stars. This paper summarizes highlights from XEST and reviews the key role of this large project. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献