Mars mesospheric zonal wind around northern spring equinox from infrared heterodyne observations of CO2     

Guido Sonnabend  Manuela Sornig  Peter Kroetz  Dusan Stupar 《Icarus》2012,217(1):315-321

We present direct observations of Mars zonal wind velocities around northern spring equinox (L_S = 336°, L_S = 355°, L_S = 42°) during martian year 27 and 29. Data was acquired by means of infrared heterodyne spectroscopy of CO₂ features at 959.3917 cm^?1 (10.4232 μm) and 957.8005 cm^?1 (10.4405 μm) using the Cologne Tuneable Heterodyne Infrared Spectrometer (THIS) at the McMath–Pierce telescope of the National Solar Observatory on Kitt Peak in Arizona and the NASA Infrared Telescope Facility on Mauna Kea, Hawaii between 2005 and 2008. Winds were measured on the dayside of Mars with an unprecedented spatial resolution allowing sampling of up to nine independent latitudes over the martian disk. Retrieved wind velocities depend strongly on latitude and season with values ranging from 180 m/s prograde to ?94 m/s retrograde. A comparison of the observational results to predicted values from the Mars Climate Database yield a reasonable agreement between modeling and observation.  相似文献   

Quantitative methods for estimating flood fatalities: towards the introduction of loss-of-life estimation in the assessment of flood risk   总被引：1，自引：0，他引：1  

Manuela Di Mauro  Karin M. De Bruijn  Matteo Meloni 《Natural Hazards》2012,63(2):1083-1113

Risk, including flood risk, can be defined as ??the combination of the probability of an event and its consequences??. Assessing and managing the risk from flooding should explicitly include the estimation of impacts to people. Extensive research is currently ongoing looking at both quantitative and qualitative approaches for assessing flood impacts on people. Although there is some literature available on such approaches, examples of methodological and routinely applications of these methodologies as part of flood risk assessments are rare. This paper focuses on quantitative approaches for estimating impacts of flooding to people, notably on methods for assessing fatality numbers associated with flooding. Three methods for assessing losses of life are discussed in detail. The methods discussed here constitute the forefront of research in Canada, UK and The Netherlands. These methods provide an assessment of the physical consequences of flooding on people and can be used to introduce the impacts to people as quantitative metric for the assessment of flood risk. In this paper, the three methodologies are discussed and applied in a UK case study reproducing the 1953 East Coast flood event. This study aims to provide a comprehensive comparison on both the reliability and the applicability of the methods. We analyse possible added values on using of these methods in systematic analyses, aiming to provide guidelines for applying these methods for flood fatality risk assessment.  相似文献   

Lithium isotopes as indicators of meteorite parent body alteration     

Mark A. Sephton  Rachael H. James  Manuela A. Fehr  Philip A. Bland  Matthieu Gounelle 《Meteoritics & planetary science》2013,48(5):872-878

Hydrothermal processing on planetesimals in the early solar system produced new mineral phases, including those generated by the transformation of anhydrous silicates into their hydrated counterparts. Carbonaceous chondrites represent tangible remnants of such alteration products. Lithium isotopes are known to be responsive to aqueous alteration, yet previously recognized variability within whole rock samples from the same meteorite appears to complicate the use of these isotopes as indicators of processing by water. We demonstrate a new way to use lithium isotopes that reflects aqueous alteration in carbonaceous chondrites. Temperature appears to exert a control on the production of acetic acid‐soluble phases, such as carbonates and poorly crystalline Fe‐oxyhydroxides. Temperature and degree of water‐rock interaction determines the amount of lithium isotope fractionation expressed as the difference between whole rock and acetic acid‐leachable fractions. Using these features, the type 1 chondrite Orgueil (δ⁷Li_{(whole rock)} = 4.3‰; Δ⁷Li_{(acetic‐whole)} = 1.2‰) can be distinguished from the type 2 chondrites Murchison (δ⁷Li_{(whole rock)} = 3.8; Δ⁷Li_{(acetic‐whole)} = 8.8‰) and carbonate‐poor Tagish Lake (δ⁷Li_{(whole rock)} = 4.3; Δ⁷Li_{(acetic‐whole)} = 9.4‰). This initial study suggests that lithium isotopes have the potential to reveal the role of liquid water in the early solar system.  相似文献   

Combined Earth orientation parameters based on homogeneous and continuous VLBI and GPS data   总被引：1，自引：3，他引：1  

Daniela Thaller  Manuela Krügel  Markus Rothacher  Volker Tesmer  Ralf Schmid  Detlef Angermann 《Journal of Geodesy》2007,81(6-8):529-541

The CONT02 campaign is of great interest for studies combining very long baseline interferometry (VLBI) with other space-geodetic techniques, because of the continuously available VLBI observations over 2 weeks in October 2002 from a homogeneous network. Especially, the combination with the Global Positioning System (GPS) offers a broad spectrum of common parameters. We combined station coordinates, Earth orientation parameters (EOPs) and troposphere parameters consistently in one solution using technique- specific datum-free normal equation systems. In this paper, we focus on the analyses concerning the EOPs, whereas the comparison and combination of the troposphere parameters and station coordinates are covered in a companion paper in Journal of Geodesy. In order to demonstrate the potential of the VLBI and GPS space-geodetic techniques, we chose a sub-daily resolution for polar motion (PM) and universal time (UT). A consequence of this solution set-up is the presence of a one-to-one correlation between the nutation angles and a retrograde diurnal signal in PM. The Bernese GPS Software used for the combination provides a constraining approach to handle this singularity. Simulation studies involving both nutation offsets and rates helped to get a deeper understanding of this singularity. With a rigorous combination of UT1–UTC and length of day (LOD) from VLBI and GPS, we showed that such a combination works very well and does not suffer from the systematic effects present in the GPS-derived LOD values. By means of wavelet analyses and the formal errors of the estimates, we explain this important result. The same holds for the combination of nutation offsets and rates. The local geodetic ties between GPS and VLBI antennas play an essential role within the inter-technique combination. Several studies already revealed non-negligible discrepancies between the terrestrial measurements and the space-geodetic solutions. We demonstrate to what extent these discrepancies propagate into the combined EOP solution.  相似文献   

On the origin of saline fluids in the KTB (continental deep drilling project of Germany)     

Manuela Lodemann  Peter Fritz  Manfred Wolf  Miro Ivanovich  Bent T. Hansen  Eckehart Nolte 《Applied Geochemistry》1997,12(6):831-849

Highly saline fluids were encountered during the German Continental Deep Drilling Project (KTB) from depths ranging between 2 and 3 km to about 9 km. The most reliable data were obtained from samples extracted during a long-term pumping test in the 4000-m deep KTB pilot hole. Some 460 m³ CaNaCl brines with about 68 g l⁻¹ total dissolved solids (TDS) and some 270 m³ associated gases, mainly N₂ and CH₄ were pumped to the surface from the main fracture system situated near the bottom of the pilot hole. Geochemical and isotopic data support the hydraulic tests which suggest the presence of an open and large fluid reservoir at depth. The pumped fluids from this main fracture system were released from a deep reservoir situated at more than 5500 m depth which is hydraulically connected with the 9101 m deep KTB main hole, drilled some 250 m to the northeast of the pilot hole.While Ca and Sr contents of the extracted brines may be the result of water-rock interaction, Cl is most likely of external origin. The Cl is hypothesized to derive from geotectonic processes rather than to descending infiltration of paleo-seawater (evaporitic brines). The sampled fluids have probably migrated from a deeper reservoir to their present position since the Cretaceous-Tertiary period due to tectonic activity. However, several isotopic studies have identified an admixture of descending paleowaters down to more than 4000 m depth. The high ³⁶ClCl ratio of the fluids sampled during the long-term pumping test point to a host rock highly enriched in UTh, unlike the sampled KTB country rocks. The fluid reservoir is believed to be in contact with the Falkenberg granite massif situated about 2 km to the E of the KTB holes capable of supplying sufficient neutron flux for considerable subsurface production of 36C1. The NaCl(K, SO₄) precursor fluids of the CaNaCI brines were produced in the course of extensive tectonic processes since the Late Caledonian within the Bohemian Massif.  相似文献   

Correlation between nitrate concentration in groundwater and parameters affecting aquifer intrinsic vulnerability   总被引：3，自引：0，他引：3  

Laura Debernardi  Domenico Antonio De Luca  Manuela Lasagna 《Environmental Geology》2008,55(3):539-558

This paper is the result of a study which was carried out in order to verify if the traditional methods to evaluate the intrinsic vulnerability or vulnerability related parameters, are able to clarify the problem of nitrate pollution in groundwater. In particular, the aim was to evaluate limitations and problems connected to aquifer vulnerability methods applied to nitrate contamination prevision in groundwater. The investigation was carried out by comparing NO₃ ⁻ concentrations, measured in March and November 2004 in the shallow aquifer, and the vulnerability classes, obtained by using GOD and TOT methods. Moreover, it deals with a comparison between NO₃ ⁻ concentrations and single parameters (depth to water table, land use and nitrogen input). The study area is the plain sector of Piemonte (Northern Italy), where an unconfined aquifer nitrate contamination exists. In this area the anthropogenic presence is remarkable and the input of N-fertilizers and zootechnical effluents to the soil cause a growing amount of nitrates in groundwater. This approach, used in a large area (about 10,000 km²) and in several monitoring wells (about 500), allowed to compare the efficiency of different vulnerability methods and to verify the importance of every parameter on the nitrate concentrations in the aquifer. Furthermore it allowed to obtain interesting correlations in different hydrogeological situations. Correlations between depth to water table, land use and nitrogen input to the soil with nitrate concentrations in groundwater show unclear situations: in fact these comparisons describe the phenomenon trend and highlight the maximum nitrate concentrations for each circumstance but often show wide ranges of possible nitrate concentrations. The same situation could be observed by comparing vulnerability indexes and nitrate concentrations in groundwater. These results suggest that neither single parameters nor vulnerability methods (GOD and TOT) are able to describe individually the complex phenomena affecting nitrate concentrations in soil, subsoil and groundwater. In particular, the traditional methods for vulnerability analysis do not analyze physical processes in aquifers, such as denitrification and nitrate dilution. According to a recent study in the shallow unconfined aquifer of the Piemonte plain, dilution can be considered as the main cause for nitrate attenuation in groundwater.  相似文献   

Long-term TNT and DNT contamination: 1-D modeling of natural attenuation in the vadose zone: case study,Portugal     

Helena?I.?F.?AmaralEmail author  Ana Claúdia?Gama  Cláudia?Gon?alves  Judite?Fernandes  Maria?Jo?o?Batista  Manuela?Abreu 《Environmental Earth Sciences》2016,75(1):89

The vadose zone of a trinitrotoluene (TNT) and dinitrotoluene (DNT) contaminated site was investigated to assess the mobility of those explosives under natural conditions. Located in the left margin of the River Tejo Basin, Portugal, the site is located on unconsolidated sediments. Wastewaters associated with the 50-year explosives production were disposed in excavated ponds, from where water would infiltrate and pollute the unsaturated and saturated parts of the local aquifers. Two boreholes were drilled to 9 m depth in such a former waste pond to investigate the contaminant’s fate in the vadose zone. Sediment samples were taken every 1–2 m for analysis of the poly-nitroaromatics (p-NACs) and organic volatile compounds, pH, organic carbon content, cation exchange capacity and grain size analysis. The main contaminant was TNT representing >70 % of the total p-NACs concentration that peaked approximately 7 mg/kg in one borehole, even if the median in both boreholes was of ~1 mg/kg. DNT was 4–30 % of the total p-NACs and nitrotoluene (NT), up to 5 %. No other (volatile) organic compound was detected. The predominance of TNT as the main contaminant implies that any natural mass reduction has been inefficient to clean the site. Several 1-D model simulations of p-NACs cleaning of the vadose zone under natural conditions indicated that the most probable scenario of combined advection and partitioning will only remove TNT after 10’s of years, whereas DNT and NT will hardly be removed. Such low concentrations and long times for the p-NACs removal, suggest that by now those compounds have been washed-out to a level below standard limits.  相似文献   

Global risks of Bedellia somnulentella (Lepidoptera: Bedelliidae) invasion: a modeling exercise using a mechanistic model,CLIMEX     

dos Santos  Marinalva Martins  da Silva  Ricardo Siqueira  Soares  Marcus Alvarenga  Lopes  Érika Manuela Gonçalves  Shabani  Farzin 《Theoretical and Applied Climatology》2022,149(1-2):401-411

Theoretical and Applied Climatology - This study aimed to identify the global risk of invasion and establishment of Bedellia somnulentella, a pest of the sweet potato crop, for the present and...  相似文献   

Are changes in the structure of nematode assemblages reliable indicators of moderate petroleum contamination?     

Daniel Silva Leite  Leonardo Sandrini-Neto  Manuela Zeglin Camargo  Micheli Cristina Thomas  Paulo C. Lana 《Marine pollution bulletin》2014

This study assesses through a multiple before-after-control-impact (MBACI) design the effects of diesel oil on the structure of nematode assemblages in unvegetated tidal flats of a subtropical estuary. Oil-exposed treatments were contrasted with controls for a duration of four successive days before and after an experimental spill in three distinct areas of the Paranaguá Estuarine Complex (Southern Brazil). No significant differences were observed in nematode total density, number of taxa and the overall assemblage structure between the control and impact treatments from before to after the experimental spill. This reinforces the idea that, despite being good indicators of environmental stress, free-living marine nematodes are able to tolerate low concentrations of hydrocarbons and to survive in moderately contaminated areas. We also show that robust experimental designs are useful to avoid confounding expected natural variability with the effects of a mild impact.  相似文献   

Spatio-temporal stochastic modelling (METMAVI)     

Raquel Menezes  A. Manuela Gonçalves 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(5):1167-1169

Editorial letter for the Special Issue dedicated to the VI International Workshop on Spatio-temporal Modelling (METMAVI), which took place in Guimarães, Portugal, from 12 to 14 September 2012. This SI summarizes the main contributions made at METMAVI, related to spatio-temporal methodology illustrated with environmental applications.  相似文献