Simulated circum-Arctic climate changes by the end of the 21st century   总被引：1，自引：0，他引：1  

Annette Rinke  Klaus Dethloff 《Global and Planetary Change》2008,62(1-2):173-186

This study investigates future changes of the Arctic climate by the end of the 21st century, simulated by the regional climate model HIRHAM forced with the ECHAM5/MPI-OM general circulation model and assuming the SRES A1B emission scenario. This assessment provides the regional patterns of future circulation, temperature, and precipitation in the Arctic by the end of the 21st century. The magnitude of winter and summer temperature and precipitation is projected to increase, while their interannual variability is projected to change seasonally and is regionally dependent. The regional-scale response of the temperature and precipitation is associated with changes in storm tracks and atmospheric baroclinicity. During winter, the regions of strongest baroclinicity are shifted northward and strengthened. Changes in the seasonal temperature and precipitation are accompanied by changes in their extremes. Extreme warm and cold events are significantly projected to change, with relative changes of seasonal precipitation being larger than those of precipitation extremes.  相似文献   

Regaining momentum for international climate policy beyond Copenhagen     

Michael Huettner  Annette Freibauer  Constanze Haug  Uwe Cantner 《Carbon balance and management》2010,5(1):2

The 'Copenhagen Accord' fails to deliver the political framework for a fair, ambitious and legally-binding international climate agreement beyond 2012. The current climate policy regime dynamics are insufficient to reflect the realities of topical complexity, actor coalitions, as well as financial, legal and institutional challenges in the light of extreme time constraints to avoid 'dangerous' climate change of more than 2°C. In this paper we analyze these stumbling blocks for international climate policy and discuss alternatives in order to regain momentum for future negotiations.  相似文献   

Tsunami hazard assessment in the Hudson River Estuary based on dynamic tsunami–tide simulations     

Michael Shelby  Stéphan T. Grilli  Annette R. Grilli 《Pure and Applied Geophysics》2016,173(12):3999-4037

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Meteorology and oceanography of the Atlantic sector of the Southern Ocean—a review of German achievements from the last decade     

Hartmut H. Hellmer  Monika Rhein  Günther Heinemann  Janna Abalichin  Wafa Abouchami  Oliver Baars  Ulrich Cubasch  Klaus Dethloff  Lars Ebner  Eberhard Fahrbach  Martin Frank  Gereon Gollan  Richard J. Greatbatch  Jens Grieger  Vladimir M. Gryanik  Micha Gryschka  Judith Hauck  Mario Hoppema  Oliver Huhn  Torsten Kanzow  Boris P. Koch  Gert König-Langlo  Ulrike Langematz  Gregor C. Leckebusch  Christof Lüpkes  Stephan Paul  Annette Rinke  Bjoern Rost  Michiel Rutgers van der Loeff  Michael Schröder  Gunther Seckmeyer  Torben Stichel  Volker Strass  Ralph Timmermann  Scarlett Trimborn  Uwe Ulbrich  Celia Venchiarutti  Ulrike Wacker  Sascha Willmes  Dieter Wolf-Gladrow 《Ocean Dynamics》2016,66(11):1379-1413

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Quantification of Long-Range Persistence in Geophysical Time Series: Conventional and Benchmark-Based Improvement Techniques     

Annette Witt  Bruce D. Malamud 《Surveys in Geophysics》2013,34(5):541-651

Time series in the Earth Sciences are often characterized as self-affine long-range persistent, where the power spectral density, S, exhibits a power-law dependence on frequency, f, S(f) ~ f ^?β , with β the persistence strength. For modelling purposes, it is important to determine the strength of self-affine long-range persistence β as precisely as possible and to quantify the uncertainty of this estimate. After an extensive review and discussion of asymptotic and the more specific case of self-affine long-range persistence, we compare four common analysis techniques for quantifying self-affine long-range persistence: (a) rescaled range (R/S) analysis, (b) semivariogram analysis, (c) detrended fluctuation analysis, and (d) power spectral analysis. To evaluate these methods, we construct ensembles of synthetic self-affine noises and motions with different (1) time series lengths N = 64, 128, 256, …, 131,072, (2) modelled persistence strengths β _model = ?1.0, ?0.8, ?0.6, …, 4.0, and (3) one-point probability distributions (Gaussian, log-normal: coefficient of variation c _v = 0.0 to 2.0, Levy: tail parameter a = 1.0 to 2.0) and evaluate the four techniques by statistically comparing their performance. Over 17,000 sets of parameters are produced, each characterizing a given process; for each process type, 100 realizations are created. The four techniques give the following results in terms of systematic error (bias = average performance test results for β over 100 realizations minus modelled β) and random error (standard deviation of measured β over 100 realizations): (1) Hurst rescaled range (R/S) analysis is not recommended to use due to large systematic errors. (2) Semivariogram analysis shows no systematic errors but large random errors for self-affine noises with 1.2 ≤ β ≤ 2.8. (3) Detrended fluctuation analysis is well suited for time series with thin-tailed probability distributions and for persistence strengths of β ≥ 0.0. (4) Spectral techniques perform the best of all four techniques: for self-affine noises with positive persistence (β ≥ 0.0) and symmetric one-point distributions, they have no systematic errors and, compared to the other three techniques, small random errors; for anti-persistent self-affine noises (β < 0.0) and asymmetric one-point probability distributions, spectral techniques have small systematic and random errors. For quantifying the strength of long-range persistence of a time series, benchmark-based improvements to the estimator predicated on the performance for self-affine noises with the same time series length and one-point probability distribution are proposed. This scheme adjusts for the systematic errors of the considered technique and results in realistic 95 % confidence intervals for the estimated strength of persistence. We finish this paper by quantifying long-range persistence (and corresponding uncertainties) of three geophysical time series—palaeotemperature, river discharge, and Auroral electrojet index—with the three representing three different types of probability distribution—Gaussian, log-normal, and Levy, respectively.  相似文献   

Simultaneous Determination of 11 Sulfonamides by HPLC–UV and Application for Fast Screening of Their Aerobic Elimination and Biodegradation in a Simple Test     

Waleed M. M. Mahmoud  Nareman D. H. Khaleel  Ghada M. Hadad  Randa A. Abdel‐Salam  Annette Haiß  Klaus Kümmerer 《洁净——土壤、空气、水》2013,41(9):907-916

Sulfonamides (SAs) are one of the most frequently used antibiotics. SAs have been found in various environmental compartments. If SAs are not degraded in the environment, they can affect bacteria by their antibiotic properties and contribute to bacterial antibiotic resistance. Therefore, the biodegradability of 11 SAs (sulfanilamide, sulfaguanidine monohydrate, sulfadiazine, sulfathiazole, sulfapyridine, sulfamerazine, sulfamethoxypyridazine, sulfachloropyridazine, sulfamethazine, sulfamethoxazole, and sulfadimethoxine) was studied. For this purpose, the Closed Bottle Test (CBT, OECD 301D) was performed, which includes a toxicity control. In order to monitor the environmental fate of the parent compound and to check for transformation products, a simple, efficient, and reliable HPLC–UV method for the simultaneous determination of these SAs has been developed. Acetonitrile and water (with 0.1% formic acid) were used as mobile phase solvents for gradient elution. The method was validated in terms of precision, detection and quantitation limits, selectivity, and analytical solution stability. In the CBT, none of these SAs was readily biodegradable. The HPLC–UV analysis confirmed that no degradation of any SA took place. In the toxicity control, these SAs showed no toxic effect in the used concentration of environmental bacteria applied in the test.  相似文献   

Factors influencing willingness to participate in disaster reduction     

Xiaofeng Luo  Annette E. Levi 《Natural Hazards》2013,66(2):1243-1255

This research is based on a questionnaire of 556 peasant households in the Jianghan Plain. By analyzing the rate of participation of peasant households using a participation model, this study intends to explain the peasant household’s willingness to participate in disaster reduction and factors that influence willingness to participate. The investigation of participation rate revealed that households are generally concerned about engineering measures used for disaster reduction, but the willingness to participate is not strong; the peasant household’s attention to recommendations for non-engineering disaster reduction is high, but the willingness to participate is very low. The quantitative analysis of the participation model of disaster reduction showed that the level of peasant household’s willingness to participate in engineering and non-engineering disaster reduction was dependent upon their attitude toward a variety of measures of risk and the input costs of disaster reduction. The cognition of a disaster’s impact, fertility level of farmland, condition of irrigation canals, and amount of arable land have a remarkable influence on the willingness to participate in engineering and non-engineering disaster reduction. Age of household and joining cooperating organizations do not influence the willingness to participate in engineering and non-engineering disaster reduction. On the other hand, the education level, professional skills, and family size influence on one dimension of disaster reduction, but do not influence another dimension of disaster reduction.  相似文献   

Vegetation patterns and diversity along an altitudinal and a grazing gradient in the Jabal al Akhdar mountain range of northern Oman   总被引：1，自引：0，他引：1  

Katja Brinkmann  Annette Patzelt  Uta Dickhoefer  Eva Schlecht  Andreas Buerkert 《Journal of Arid Environments》2009,73(11):1035-1045

Little is known about the effects of grazing on vegetation composition on the Arabian Peninsula. The aim of this study therefore was to analyse the vegetation response to environmental conditions of open woodlands along an altitudinal and a grazing gradient in the Jabal al Akhdar mountain range of Oman. The species composition, vegetation structure, grazing damage and several environmental variables were investigated for 62 samples using a nested plot design. Classification analysis and a Canonical Variate Analysis (CVA) were used to define vegetation types and to identify underlying environmental gradients. The relationship between environmental variables and diversity was analysed using correlation coefficients and a main-effects ANOVA. The plant species richness followed a unimodal distribution along the altitudinal gradient with the highest number of species at the intermediate altitudinal belt. The cluster analysis led to five vegetation groups: The Sideroxylon mascatense–Dodonaea viscosa group on grazed and the Olea europaea–Fingerhuthia africana group on ungrazed plateau sites at 2000 m a.s.l., the Ziziphus spina-christi–Nerium oleander group at wadi sites and the Moringa peregrina–Pteropyrum scoparium group at 1200 m a.s.l, and the Acacia gerrardii–Leucas inflata group at 1700 m a.s.l. The CVA indicated a clear distinction of the groups obtained by the agglomerative cluster analysis. The landform, altitude and grazing intensity were found to be the most important variables distinguishing between clusters. Overgrazing of the studied rangeland is an increasing environmental problem, whereas the plant composition at ungrazed sites pointed to a relatively fast and high regeneration potential of the local vegetation.  相似文献   

Standardized precipitation evaporation index (SPEI)-based drought assessment in semi-arid south Texas   总被引：3，自引：0，他引：3  

E. Annette Hernandez  Venkatesh Uddameri 《Environmental Earth Sciences》2014,71(6):2491-2501

The coastal semi-arid region of south Texas is known for its erratic climate that fluctuates between long periods of drought and extremely wet hurricane-induced storms. The standard precipitation index (SPI) and the standard precipitation evaporation index (SPEI) were used in this study in conjunction with precipitation and temperature projections from two general circulation models (GCMs), namely, the National Center for Atmospheric Research (NCAR) Parallel Climate Model (PCM) and the UK Meteorological Office Hadley Centre model (HCM) for two emission scenarios—A1B (~720 ppm CO₂ stabilization) and B1 (~550 ppm CO₂ stabilization) at six major urban centers of south Texas spanning five climatic zones. Both the models predict a progressively increasing aridity of the region throughout the twenty-first century. The SPI exhibits greater variability in the available moisture during the first half of the twenty-first century while the SPEI depicts a downward trend caused by increasing temperature. However, droughts during the latter half of the twenty-first century are due to both increasing temperature and decreasing precipitation. These results suggest that droughts during the first half of the twenty-first century are likely caused by meteorological demands (temperature or potential evapotranspiration (PET) controlled), while those during the latter half are likely to be more critical as they curtail moisture supply to the region over large periods of time (precipitation and PET controlled). The drought effects are more pronounced for the A1B scenario than the B1 scenario and while spatial patterns are not always consistent, the effects are generally felt more strongly in the hinterlands than in coastal areas. The projected increased warming of the region, along with potential decreases in precipitation, points toward increased reliance on groundwater resources which are noted to be a buffer against droughts. However, there is a need for human adaptation to climate change, a greater commitment to groundwater conservation and development of large-scale regional aquifer storage and recovery (ASR) facilities that are capable of long-term storage in order to sustain groundwater availability. Groundwater resource managers and planners must confront the possibility of an increased potential for prolonged (multi-year) droughts and develop innovative strategies that effectively integrate water augmentation technologies and conservation-oriented policies to ensure the sustainability of aquifer resources well into the next century.  相似文献   

Characterization of differential throughfall drop size distributions beneath European beech and Norway spruce     

Marvin Lüpke  Michael Leuchner  Delphis Levia  Kazuki Nanko  Shin'ichi Iida  Annette Menzel 《水文研究》2019,33(26):3391-3406

Forest canopies present irregular surfaces that alter both the quantity and spatiotemporal variability of precipitation inputs. The drop size distribution (DSD) of rainfall varies with rainfall event characteristics and is altered substantially by the forest stand properties. Yet, the influence of two major European tree species, European beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) H. Karst), on throughfall DSD is largely unknown. In order to assess the impact of these two species with differing canopy structures on throughfall DSD, two optical disdrometers, one above and one below the canopy of each European beech and Norway spruce, measured DSD of both incident rainfall and throughfall over 2 months at a 10‐s resolution. Fractions of different throughfall categories were analysed for single‐precipitation events of different intensities. While penetrating the canopies, clear shifts in drop size and temporal distributions of incoming rainfall were observed. Beech and spruce, however, had different DSD, behaved differently in their effect on diameter volume percentiles as well as width of drop spectrum. The maximum drop sizes under beech were higher than under spruce. The mean ± standard deviation of the median volume drops size (D50) over all rain events was 2.7 ± 0.28 mm for beech and 0.80 ± 0.04 mm for spruce, respectively. In general, there was a high‐DSD variability within events indicating varying amounts of the different throughfall fractions. These findings help to better understand the effects of different tree species on rainfall partitioning processes and small‐scale variations in subcanopy rainfall inputs, thereby demonstrating the need for further research in high‐resolution spatial and temporal properties of rainfall and throughfall.  相似文献