North Sea – Caspian Pattern (NCP) – an upper level atmospheric teleconnection affecting the eastern Mediterranean – implications on the regional climate     

H. Kutiel  P. Maheras  M. Türkeş  S. Paz 《Theoretical and Applied Climatology》2002,72(3-4):173-192

Summary ?A calendar of the negative and positive phases of the North Sea – Caspian Pattern (NCP) for the period 1958–1998 was used to analyse the implication of the NCP upper level teleconnections on the regional climate of the eastern Mediterranean basin. Series of monthly mean air temperature and monthly total rainfall from 33 stations across Greece, Turkey and Israel, for the same period, were used. For each month, from October to April, averages of the monthly mean temperatures and the monthly rainfall totals as well as the standardized values of both parameters were calculated separately for the negative (NCP (−)) and the positive (NCP (+)) phases of the NCP. At all stations and in all months, temperature values were significantly higher during the NCP (−) as compared with the NCP (+). Furthermore, apart from very few exceptions, the absolute monthly mean maximum and monthly mean minimum values were obtained during the NCP (−) and the NCP (+) phases, respectively. The maximum impact of the NCP on mean air temperature was detected in the continental Anatolian Plateau, where the mean seasonal differences are around 3.5 °C. This influence decreases westwards and southwards. The influence on the rainfall regime is more complex. Regions exposed to the southern maritime trajectories, in Greece and in Turkey, receive more rainfall during the NCP (−) phase, whereas in the regions exposed to the northern maritime trajectories, such as Crete in Greece, the Black Sea region in Turkey, and in all regions of Israel, there is more rainfall during the NCP (+) phase. The accumulated rainfall differences between the two phases are over 50% of the seasonal average for some stations. A comparison of the capabilities of the NCP, the North Atlantic Oscillation (NAO) and the Southern Oscillation (SO) indices to differentiate between below and above normal temperatures was made. The results have placed the NCP, as the best by far of all three teleconnections in its ability to differentiate between below or above normal temperatures and as the main teleconnection affecting the climate of the Balkans, the Anatolian Peninsula and the Middle East. These results may serve to downscale General Circulation Model (GCM) scenarios to a regional scale and provide forecasts regarding eventual temperature and/or precipitation changes. Received June 25, 2001; revised February 25, 2002; accepted March 3, 2002  相似文献   

NIR Properties of the UCM Star-Forming Galaxies     

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   

Linking SO2 emission rates and seismicity by continuous wavelet transform: implications for volcanic surveillance at San Cristóbal volcano,Nicaragua     

Vladimir Conde  Stefan Bredemeyer  J. Armando Saballos  Bo Galle  Thor H. Hansteen 《International Journal of Earth Sciences》2016,105(5):1453-1465

  相似文献   

Potential Impacts of Climate Change on Agriculture: A Case of Study of Coffee Production in Veracruz, Mexico   总被引：1，自引：1，他引：1  

C. Gay  F. Estrada  C. Conde  H. Eakin  L. Villers 《Climatic change》2006,79(3-4):259-288

This paper explores the relation between coffee production and climatic and economic variables in Veracruz in order to estimate the potential impacts of climate change. For this purpose, an econometric model is developed in terms of those variables. The model is validated by means of statistical analysis, and then used to project coffee production under different climatic conditions. Climate change scenarios are produced considering that the observed trends of climate variables will continue to prevail until the year 2020. An approach for constructing simple probability scenarios for future climate variability is presented and used to assess possible impacts of climate change beyond what is expected from changes in mean values. The model shows that temperature is the most relevant climatic factor for coffee production, since production responds significantly to seasonal temperature patterns. The results for the projected climate change conditions for year 2020 indicate that coffee production might not be economically viable for producers, since the model indicates a reduction of 34% of the current production. Although different economic variables (the state and international coffee prices, a producer price index for raw materials for coffee benefit, the national and the USA coffee stocks) were considered as potentially relevant, our model suggests that the state real minimum wage could be regarded as the most important economic variable. Real minimum wage is interpreted here as a proxy for the price of labor employed for coffee production. This activity in Mexico is very labor intensive representing up to 80% of coffee production costs. As expected, increments in the price of such an important production factor increase production costs and have strong negative effects on production. Different assumptions on how real minimum wage could evolve for the year 2020 are considered for developing future production scenarios.  相似文献   

Cenozoic basin evolution of the Central Patagonian Andes: Evidence from geochronology,stratigraphy, and geochemistry     

A.Encinas  A.Folguera  R.Riffo  P.Molina  L.Fernández Paz  V.D.Litvak  D.A.Colwyn  V.A.Valencia  M.Carrasco 《地学前缘(英文版)》2019,10(3):1139-1165

The Central Patagonian Andes is a particular segment of the Andean Cordillera that has been subjected to the subduction of two spreading ridges during Eocene and Neogene times. In order to understand the Cenozoic geologic evolution of the Central Patagonian Andes, we carried out geochronologic(U-Pb and⁴⁰Ar/³⁹Ar), provenance, stratigraphic, sedimentologic, and geochemical studies on the sedimentary and volcanic Cenozoic deposits that crop out in the Meseta Guadal and Chile Chico areas(～47°S). Our data indicate the presence of a nearly complete Cenozoic record, which refutes previous interpretations of a hiatus during the middle Eocene-late Oligocene in the Central Patagonian Andes. Our study suggests that the fluvial strata of the Ligorio Marquez Formation and the flood basalts of the Basaltos Inferiores de la Meseta Chile Chico Formation were deposited in an extensional setting related to the subduction of the Aluk-Farallon spreading ridge during the late Paleocene-Eocene. Geochemical data on volcanic rocks interbedded with fluvial strata of the San Jose Formation suggest that this unit was deposited in an extensional setting during the middle Eocene to late Oligocene. Progressive crustal thinning allowed the transgression of marine waters of Atlantic origin and deposition of the upper Oligocene-lower Miocene Guadal Formation. The fluvial synorogenic strata of the Santa Cruz Formation were deposited as a consequence of an important phase of compressive deformation and Andean uplift during the early-middle Miocene. Finally, alkali flood basalts of the late middle to late Miocene Basaltos Superiores de la Meseta Chile Chico Formation were extruded in the area in response to the suduction of the Chile Ridge under an extensional regime. Our studies indicate that the tectonic evolution of the Central Patagonian Andes is similar to that of the North Patagonian Andes and appears to differ from that of the Southern Patagonian Andes, which is thought to have been the subject of continuous compressive deformation since the late Early Cretaceous.  相似文献   

Bioremediation of Oil‐Contaminated Beach and Restinga Sediments Using a Slow‐Release Fertilizer          下载免费PDF全文

Beatriz Rohden Becker  Eliane Soares de Souza  Rodrigo Lemes Martins  Júlia da Luz Bueno 《洁净——土壤、空气、水》2016,44(9):1154-1162

  相似文献   

Reproductive seasonality of the fish fauna and limnoecology of semi-arid Brazilian reservoirs   总被引：1，自引：1，他引：0  

Sathyabama Chellappa  Regina M.X. Bueno  Thiago Chellappa  Naithirithi T. Chellappa  Vera Maria Fonseca Almeida e Val 《Limnologica》2009,39(4):325-329

The native fish fauna commonly found in the drainage basins of rivers and reservoirs of Latin America, including those of the semi-arid Northeastern Brazil, are representatives of the Neotropical region. This work reports on the reproductive ecology of five commercially important and consumable native fish species, in relation to rainfall and hydrological variables of the semi-arid reservoirs in Brazil. Pluviometric precipitation, temperature, pH, dissolved oxygen and electrical conductivity of the water were registered, and maturation of fish gonads was assessed on a monthly basis. This region is characterized with short spells of rain interspersed with long dry season and rainfall seems to be the main environmental factor which modulates the timing of the spawning period of fish. Construction of reservoirs without adequate facilities for fish migration has an adverse impact on the migratory fish species which are of commercial and ecological importance to semi-arid Northeastern Brazil.  相似文献   

Chlorella-bearing ciliates (Stentor, Ophrydium) dominate in an oligotrophic, deep North Patagonian lake (Lake Caburgua, Chile)     

Stefan Woelfl  Paz Garcia 《Limnologica》2010,40(2):134-139

The aim of this study was to present quantitative data on the population dynamics of Chlorella-bearing ciliates (Stentor, Ophrydium) compared to the total zooplankton community in a deep, oligotrophic North Patagonian lake. Mixotrophic and heterotrophic ciliates, rotifers and microcrustaceans, and important ecological parameters were sampled during a 1-year study. The results showed a low biodiversity with only a few dominant species in every zooplankton group. Three mixotrophic ciliates - Stentor araucanus, S. amethystinus and Ophrydium naumanni - were found. They peaked in summer and autumn with maximum values of 152-313 Ind L⁻¹ (Stentor) and 1880 Ind L⁻¹ (Ophrydium). Their contribution to the total ciliate abundance was 16±17% (annual average). Both Stentor species displayed a distinct vertical zonation during the stratification period with peak depth between 10 and 15 m (metalimnion). The contribution to total zooplankton biomass was 59.4% on an annual average (Stentor: 41%, O. naumanni: 18.4%) and 83% during the stratification period. Both abundance and biomass of mixotrophic ciliates correlated strongly with temperature and to a lesser degree with copepods, rotifers and small cladocerans. According to this study mixotrophic ciliates were by far the dominant zooplankton group in Lake Caburgua. We report for the first time the importance of O. naumanni in a deep Chilean North Patagonian lake.  相似文献   

The 1996 Biescas campsite disaster in the Central Spanish Pyrenees,and its temporal and spatial context     

Sue White  Jos M. García-Ruiz  Carlos Martí  Blas Valero  M. Paz Errea  Amelia Gmez-Villar 《水文研究》1997,11(14):1797-1812

On the evening of the 7 August 1996 an intense storm occurred over the Arás catchment near Biescas in the central Pyrenees. Eighty-seven people were killed as a result of the subsequent flood, which hit a campsite located on the alluvial fan at the outlet of the 18·8 km² catchment. This paper presents the main results of a hydromorphological study of the event. The Betés subcatchment received the most intense rainfall, estimated at somewhat in excess of 250 mm, which resulted in a peak flow from this tributary of 300 m³ s⁻¹. Just downstream from the Betés river junction, flow in the main channel reached 400 m³ s⁻¹, increasing to around 500 m³ s⁻¹ further downstream. Rainfall in the larger Aso tributary was less intense, and in the head reaches flow remained within-bank, representing a one in two-year return period event. Flow from this tributary did not exceed 100 m³ s⁻¹, indicating that the Betés subcatchment supplied some 75% of the flow from just 28·7% of the catchment area. The extreme flows caused the collapse of a series of sediment trap dams in the Arás channel downstream of the Betés junction. This resulted in the addition of 68 000 m³ of sediment to an already disastrous event. Data from other rain gauges in the area showed both the extremely local nature of the event, and the problems of return period analysis for such storms, whose peaks are rarely observed at gauges. Together with the high geomorphological risks of the zone, this leads to the conclusion that a new method of spatial and temporal risk analysis is required for infrastructure planning. © 1997 John Wiley & Sons, Ltd.  相似文献