Projections of global warming-induced impacts on winter storm losses in the German private household sector     

Hermann Held  Friedrich-Wilhelm Gerstengarbe  Tobias Pardowitz  Joaquim G. Pinto  Uwe Ulbrich  Kai Born  Markus G. Donat  Melanie K. Karremann  Gregor C. Leckebusch  Patrick Ludwig  Katrin M. Nissen  Hermann Österle  Boris F. Prahl  Peter C. Werner  Daniel J. Befort  Olaf Burghoff 《Climatic change》2013,121(2):195-207

We present projections of winter storm-induced insured losses in the German residential building sector for the 21st century. With this aim, two structurally most independent downscaling methods and one hybrid downscaling method are applied to a 3-member ensemble of ECHAM5/MPI-OM1 A1B scenario simulations. One method uses dynamical downscaling of intense winter storm events in the global model, and a transfer function to relate regional wind speeds to losses. The second method is based on a reshuffling of present day weather situations and sequences taking into account the change of their frequencies according to the linear temperature trends of the global runs. The third method uses statistical-dynamical downscaling, considering frequency changes of the occurrence of storm-prone weather patterns, and translation into loss by using empirical statistical distributions. The A1B scenario ensemble was downscaled by all three methods until 2070, and by the (statistical-) dynamical methods until 2100. Furthermore, all methods assume a constant statistical relationship between meteorology and insured losses and no developments other than climate change, such as in constructions or claims management. The study utilizes data provided by the German Insurance Association encompassing 24 years and with district-scale resolution. Compared to 1971–2000, the downscaling methods indicate an increase of 10-year return values (i.e. loss ratios per return period) of 6–35 % for 2011–2040, of 20–30 % for 2041–2070, and of 40–55 % for 2071–2100, respectively. Convolving various sources of uncertainty in one confidence statement (data-, loss model-, storm realization-, and Pareto fit-uncertainty), the return-level confidence interval for a return period of 15 years expands by more than a factor of two. Finally, we suggest how practitioners can deal with alternative scenarios or possible natural excursions of observed losses.  相似文献   

Short‐term dynamics in fish assemblage structure on a sheltered sandy beach in Guanabara Bay,Southeastern Brazil     

Ruan Managna Vasconcellos  Francisco Gerson Araújo  Joaquim Neto De Sousa Santos  Márcio De Araújo Silva 《Marine Ecology》2010,31(3):506-519

Short‐term dynamics in juvenile fish assemblage structure were studied to test whether the most abundant species show temporal segregation, in order to assess whether selected environmental variables could predict species groupings, and to examine the stability of sunset–day–sunrise–night differences. Samplings were collected at 3‐h intervals over 48 h on a seasonal basis between spring 2005 and winter 2006. Fish species richness and abundance were higher in spring, and the lowest values occurred in winter. Harengula clupeola occurred mainly in spring, whereas Atherinella brasiliensis peaked in summer and autumn. On the other hand, Trachinotus carolinus, Umbrina coroides and Mugil liza were abundant in winter. Although temperature, salinity and dissolved oxygen were not found to have a strong effect on the abundance patterns of most species, they did appear to have a significant influence on assemblage groupings, according to canonical correspondence analysis and Spearman rank correlation. There is no consistency of diel usage patterns by a given species across seasons. The relative abundance differed between the time of day, which differed among the seasons; this further complicates an understanding of the dynamics of an assemblage. Studies of diel changes that pooled the sampling period as day or night can miss important changes that occur in a short time scale, such as a 3‐h period.  相似文献   

Comparison of the antioxidant defense system in Crassostrea rhizophorae and Crassostrea gigas exposed to domestic sewage discharges     

Zanette J  Nunes FF  Medeiros ID  Siebert MN  Mattos JJ  Lüchmann KH  Rodrigues de Melo CM  Bainy AC 《Marine environmental research》2008,66(1):196-198

Oysters Crassostrea rhizophorae and Crassostrea gigas were kept for fourteen days at four sites in S?o José, SC, Brazil, chosen according to a sewage discharge contamination gradient. Enzymatic activities of CAT, GST, G6PDH and GR were evaluated in gills and digestive glands. Higher CAT activity was observed in tissues of C. rhizophorae in response to sewage contamination possibly indicating peroxisome proliferation induction. C. gigas showed elevated G6PDH activity in digestive gland, and GR in gills, after domestic sewage exposure. In conclusion, C. rhizophorae and C. gigas showed different biochemical responses after in situ exposure to domestic sewage. However, C. rhizophorae showed more significant changes in CAT suggesting that this organism could be a better monitor to this kind of effluent.  相似文献   

High resolution characterization of northwest Mediterranean coastal waters thermal regimes: To better understand responses of benthic communities to climate change     

Nathaniel Bensoussan  Jean-Claude Romano  Jean-Georges Harmelin  Joaquim Garrabou 《Estuarine, Coastal and Shelf Science》2010

In the North West Mediterranean (NWM), mass mortality events (MME) of long-lived benthic species that have occurred over the last two decades have been related to regional warming trend. Gaining robust data sets on thermal regimes is critical to assess conditions to which species have adapted, detect extreme events and critically evaluate biological impacts. High resolution temperature (T) time series obtained during 1999–2006 from 5 to 40 m depth at four contrasted sites of the NWM were analyzed: Area Marina Protegida de les Illes Medes (NE Spain), Riou (Marseilles, France), Parc National de Port-Cros (France), and Réserve Naturelle de Scandola (Corsica, France). The seasonal pattern showed winter T around 11–13 °C, and summer T mainly around 22–24 °C near surface to 18–20 °C at depth. Stratification dynamics showed recurrent downwellings (>40 m) at Medes, frequent observation (1/3rd of the summer) of deep and cold upwelled waters at Riou, while Scandola exhibited stable summer stratification and highest suprathermoclinal T. Port-Cros showed an intermediate regime that oscillated between Riou and Scandola depending on the occurrence of northern winds. Data distribution study permitted to identify and to characterize 3 large scale positive anomalies concomitant with the mass mortality outbreaks of summers 1999, 2003 and 2006. The analysis of biological surveys on gorgonian populations showed significant impacts during the 3 years with temperature anomalies. Besides the degree of impact showed inter-annual differences which could be related to different T conditions concomitant to mortality events, from slight increase in T extreme of only 1–2 °C over short duration, to lengthened more classical summer conditions. Our results therefore support the hypothesis that shallow NWM populations of long-lived benthic species are living near their upper thermal thresholds. Given actual trends and projections in NWM, the repetition of new MMEs in the next decades is extremely likely. In such context, the acquisition of dedicated high resolution T series proves to be crucial for increasing our detection, understanding and forecasting abilities.  相似文献   

PS-InSAR processing methodologies in the detection of field surface deformation—Study of the Granada basin (Central Betic Cordilleras,southern Spain)     

Joaquim J. Sousa  Antonio M. Ruiz  Ramon F. Hanssen  Luisa Bastos  Antonio J. Gil  Jesús Galindo-Zaldívar  Carlos Sanz de Galdeano 《Journal of Geodynamics》2010,49(3-4):181-189

Differential SAR interferometry (DInSAR) is a very effective technique for measuring crustal deformation. However, almost all interferograms include large areas where the signals decorrelate and no measurements are possible. Persistent scatterer interferometry (PS-InSAR) overcomes the decorrelation problem by identifying resolution elements whose echo is dominated by a single scatterer in a series of interferograms.Two time series of 29 ERS-1/2 and 22 ENVISAT ASAR acquisitions of the Granada basin, located in the central sector of the Betic Cordillera (southern Spain), covering the period from 1992 to 2005, were analyzed. Rough topography of the study area associated to its moderate activity geodynamic setting, including faults and folds in an uplifting relief by the oblique Eurasian–African plate convergence, poses a challenge for the application of interferometric techniques. The expected tectonic deformation rates are in the order of ～1 mm/yr, which are at the feasibility limit of current InSAR techniques.In order to evaluate whether, under these conditions, InSAR techniques can still be used to monitor deformations we have applied and compared two PS-InSAR approaches: DePSI, the PS-InSAR package developed at Delft University of Technology (TU Delft) and StaMPS (Stanford Method for Persistent Scatterers) developed at Stanford University. Ground motion processes have been identified for the first time in the study area, the most significant process being a subsidence bowl located at the village of Otura.The idea behind this comparative study is to analyze which of the two PS-InSAR approaches considered might be more appropriate for the study of specific areas/environments and to attempt to evaluate the potentialities and benefits that could be derived for the integration of those methodologies.  相似文献   

The Warming of Lake Tahoe   总被引：1，自引：0，他引：1  

Robert Coats  Joaquim Perez-Losada  Geoffrey Schladow  Robert Richards  Charles Goldman 《Climatic change》2006,76(1-2):121-148

Summary We investigated the effects of climate variability on the thermal structure of Lake Tahoe, California-Nevada, 1970–2002, and with principal components analysis and step-wise multiple regression, related the volume-weighed average lake temperature to trends in climate. We then used a 1-dimensional hydrodynamic model to show that the observed trends in the climatic forcing variables can reasonably explain the observed changes in the lake. Between 1970 and 2002, the volume-weighted mean temperature of the lake increased at an average rate of 0.015 ^∘C yr⁻¹. Trends in the climatic drivers include 1) upward trends in maximum and minimum daily air temperature at Tahoe City; and 2) a slight upward trend in downward long-wave radiation. Changes in the thermal structure of the lake include 1) a long-term warming trend, with the highest rates near the surface and at 400 m; 2) an increase in the resistance of the lake to mixing and stratification, as measured by the Schmidt Stability and Birge Work; 3) a trend toward decreasing depth of the October thermocline. The long-term changes in the thermal structure of Lake Tahoe may interact with and exacerbate the well-documented trends in the lake's clarity and primary productivity.  相似文献   

Long-term seismicity of the Reykjanes Ridge (North Atlantic) recorded by a regional hydrophone array     

Jean Goslin  Nuno Lourenço  Robert P. Dziak  DelWayne R. Bohnenstiehl  Joe Haxel  Joaquim Luis 《Geophysical Journal International》2005,162(2):516-524

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Rubidium-strontium geochronology of granitic rocks from the Morro Vermelho area (Tiger Bay — Angola)     

Dr. Joaquim Raul Torquato  Dr. H. L. Allsopp 《International Journal of Earth Sciences》1973,62(1):172-179

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Food availability and the feeding ecology of ichthyofauna of a Ria Formosa (South Portugal) water reservoir     

Sofia Gamito  Ana Pires  Cristina Pita  Karim Erzini 《Estuaries and Coasts》2003,26(4):938-948

The feeding habits of several fish species in a water reservoir of the Ria Formosa, Portugal, that has similar ecological characteristics to the outside tidal channels, were studied and compared with food availability. The gilthead seabream (Sparus aurata), the most abundant fish species, mainly selected gastropods and bivalves, although occasionally fish and small crustaceans such as tanaids, ostracods, and cumaceans were also selected. Polychaetes, although abundant in the environment, were not particularly selected by any of the fish species studied. The diets of all the species studied were characterized by a large variety of prey, allowing them to survive in environments of low diversity and poor stability, such as coastal lagoons. These fish are largely benthic feeders, essentially eating the epimacroinvertebrates and endomacroinvertebrates and, occasionally, fish.Diplodus vulgaris andDiplodus annularis preferentially selected gastropods and small crustaceans.Spondyliosoma cantharus generally preyed on crustaceans, including the highly mobile epifauma, the mysids, and decapods.Halobatrachus didactylus andAnguilla anguilla, had very diversified diets that included fish.Mullus barbatus were found to have selected all groups of crustaceans and also bivalves. Wrasses, gobies, andDiplodus sargus, all small-sized fish, singled out small crustaceans, gastropods, and bivalves. The Sparids were the least specialized predators, with broader niches than the other species. They preferentially selected molluscs, which were abundant in the environment. A large overlap of diets was observed and competition may be important when fish biomass is high.  相似文献   

A Comparison of the Seasonality and Interannual Variability of Phytoplankton Biomass and Production in the Western and Eastern Gyres of the Subarctic Pacific Using Multi-Sensor Satellite Data     

Joaquim I. Goes  Kosei Sasaoka  Helga do R. Gomes  Sei-ichi Saitoh  Toshiro Saino 《Journal of Oceanography》2004,60(1):75-91

This study documents the results of a multi-sensor satellite investigation aimed at comparing the seasonality and interannual variability of phytoplankton biomass and primary productivity (PP) in the western and eastern gyres of the subarctic Pacific. Satellite data helped discern several features, most importantly the existence of significant east-west gradients in the supply of nitrate in winter, in the consumption of nitrate by phytoplankton and in phytoplankton production and biomass accumulation over the growth season. In the western subarctic gyre many of these features appear to be regulated by the strength of sea surface winds through increased iron and nitrate inputs. Multiple regression analysis of data extracted from 12 boxes spanning different hydrographic regimes in the subarctic Pacific, showed that over 65% of the variations in PP in the subarctic Pacific could be explained solely on the basis of changes in the strength of sea surface winds and the intensity of incident irradiance (PAR). The dependence of PP on sea surface wind stress was far greater in the western subarctic Pacific Gyre (WSG), than in the Alaskan Gyre (ALG) due to diminishing impact of surface winds towards the east. Spring accumulation of phytoplankton biomass was greater in the WSG than in the ALG despite the higher rates of PP in the latter. This study assumes particular significance because it helps ascertain the existence of several sub-regions within the two broader domains of the WSG and the ALG. In addition, large interannual variations in phytoplankton biomass and PP were observed in the subarctic Pacific following the onset of the El-Niño event of 1997 and the transition to La-Niña conditions in 1999. These variations were largely the result of differences in meteorological and oceanographic conditions across the subarctic Pacific following the development of the El-Niño.  相似文献