bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling nitrous acid and its impact on ozone and hydroxyl radical during the Texas Air Quality Study 2006
Authors: Czader B. H. , Rappenglück B. , Percell P. , Byun D. W. , Ngan F. , Kim S.
Published: August 2012

Abstract. Nitrous acid (HONO) mixing ratios for the Houston metropolitan area were simulated with the Community Multiscale Air Quality (CMAQ) Model for an episode during the Texas Air Quality Study (TexAQS) II in August/September 2006 and compared to in-situ MC/IC (mist-chamber/ion chromatograph) and long path DOAS (Differential Optical Absorption Spectroscopy) measurements at three different altitude ranges. Several HONO sources were accounted for in simulations, such as gas phase formation, direct emissions, nitrogen dioxide (NO2) hydrolysis, photo-induced formation from excited NO2 and photo-induced conversion of NO2 into HONO on surfaces covered with organic materials. Compared to the gas-phase HONO formation there was about a tenfold increase in HONO mixing ratios when additional HONO sources were taken into account, which improved the correlation between modeled and measured values. Concentrations of HONO simulated with only gas phase chemistry did not change with altitude, while measured HONO concentrations decrease with height. A trend of decreasing HONO concentration with altitude was well captured with CMAQ predicted concentrations when heterogeneous chemistry and photolytic sources of HONO were taken into account. Heterogeneous HONO production mainly accelerated morning ozone formation, albeit slightly. Also HONO formation from excited NO2 only slightly affected HONO and ozone (O3) concentrations. Photo-induced conversion of NO2 into HONO on surfaces covered with organic materials turned out to be a strong source of daytime HONO. Since HONO immediately photo-dissociates during daytime its ambient mixing ratios were only marginally altered (up to 0.5 ppbv), but significant increase in the hydroxyl radical (OH) and ozone concentration was obtained. In contrast to heterogeneous HONO formation that mainly accelerated morning ozone formation, inclusion of photo-induced surface chemistry influenced ozone throughout the day.
Can a global model reproduce observed trends in summertime surface ozone levels?
Authors: Koumoutsaris S. , Bey I.
Published: August 2012

Abstract. Quantifying trends in surface ozone concentrations is critical for assessing pollution control strategies. Here we use observations and results from a global chemical transport model to examine the trends (1991–2005) in daily maximum 8-h average concentrations in summertime surface ozone at rural sites in Europe and the United States (US). We find a decrease in observed ozone concentrations at the high end of the probability distribution at many of the sites in both regions. The model attributes these trends to a decrease in local anthropogenic ozone precursors, although simulated decreasing trends are overestimated in comparison with observed ones. The low end of observed distribution show small upward trends over Europe and the western US and downward trends in Eastern US. The model cannot reproduce these observed trends, especially over Europe and the western US. In particular, simulated changes between the low and high end of the distributions in these two regions are not significant. Sensitivity simulations indicate that emissions from far away source regions do not affect significantly summer ozone trends at both ends of the distribution in both Europe and US. Possible reasons for discrepancies between observed and simulated trends are discussed.
French airborne lidar measurements for Eyjafjallajökull ash plume survey
Authors: Chazette P. , Dabas A. , Sanak J. , Lardier M. , Royer P.
Published: August 2012

Abstract. An Ultra-Violet Rayleigh-Mie lidar has been integrated aboard the French research aircraft Falcon20 in order to monitor the ash plume emitted by the Eyjafjallajökul volcano in April–May 2010. Three operational flights were carried out on 21 April, 12 and 16 May 2010 inside French, Spanish and British air spaces, respectively. The original purpose of the flights was to provide the French civil aviation authorities with objective information on the presence and location of the ash plume. The present paper presents the results of detailed analyses elaborated after the volcano crisis. They bear on the structure of the ash clouds and their optical properties such as the extinction coefficient and the lidar ratio. Lidar ratios were measured in the range of 43 to 50 sr, in good agreement with the ratios derived from ground-based lidar near Paris (France) in April 2010 (~48 sr). The ash signature in terms of particulate depolarization was consistent during all flights (between 34 ± 3 % and 38 ± 3%). Such a value seems to be a good identification parameter for volcanic ash. Using specific cross-sections between 0.19 and 1.1 m2 g−1, the minimum (maximal) mass concentrations in the ash plumes derived for the flights on 12 and 16 May were 140 (2300) and 250 (1500) μg m−3, respectively. It may be rather less than, or of the order of the critical level of damage (2 mg m−3) for the aircraft engines, but well above the 200 μg m−3 warning level.
Improvement of aerosol optical depth retrieval from MODIS spectral reflectance over the global ocean using new aerosol models archived from AERONET inversion data and tri-axial ellipsoidal dust database
Authors: Lee J. , Kim J. , Yang P. , Hsu N. C.
Published: August 2012

Abstract. New over-ocean aerosol models are developed by integrating the inversion data from the Aerosol Robotic Network (AERONET) sun/sky radiometers with a database for the optical properties of tri-axial ellipsoid particles. The new aerosol models allow more accurate retrieval of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) in the case of high AOD (AOD > 0.3). The aerosol models are categorized by using the fine-mode fraction (FMF) at 550 nm and the single-scattering albedo (SSA) at 440 nm from the AERONET inversion data to include a variety of aerosol types found around the globe. For each aerosol model, the changes in the aerosol optical properties (AOPs) as functions of AOD are considered to better represent aerosol characteristics. Comparisons of AODs between AERONET and MODIS for the period from 2003 to 2010 show that the use of the new aerosol models enhances the AOD accuracy with a Pearson coefficient of 0.93 and a regression slope of 0.99 compared to 0.92 and 0.85 calculated using the MODIS Collection 5 data. Moreover, the percentage of data within an expected error of ± (0.03 + 0.05 × AOD) is increased from 62% to 64% for overall data and from 39% to 5% for AOD > 0.3. Errors in the retrieved AOD are further characterized with respect to the Ångström exponent (AE), scattering angle (Θ), SSA, and air mass factor (AMF). Due to more realistic AOPs assumptions, the new algorithm generally reduces systematic errors in the retrieved AODs compared with the current operational algorithm. In particular, the underestimation of fine-dominated AOD and the scattering angle dependence of dust-dominated AOD are significantly mitigated as results of the new algorithm's improved treatment of aerosol size distribution and dust particle nonsphericity.
A 60-yr record of atmospheric carbon monoxide reconstructed from Greenland firn air
Authors: Petrenko V. V. , Martinerie P. , Novelli P. , Etheridge D. M. , Levin I. , Wang Z. , Blunier T. , Chappellaz J. , Kaiser J. , Lang P. , Steele L. P. , Hammer S. , Mak J. , Langenfelds R. L. , Schwander J. , Severinghaus J. P. , Witrant E. , Petron G. , Battle M. O. , Forster G. , Sturges W. T. , Lamarque J.-F. , Steffen K. , White J. W. C.
Published: August 2012

Abstract. We present a reconstruction of the Northern Hemisphere (NH) high latitude atmospheric carbon monoxide (CO) mole fraction from Greenland firn air. Firn air samples were collected at three deep ice core sites in Greenland (NGRIP in 2001, Summit in 2006 and NEEM in 2008). CO records from the three sites agree well with each other as well as with recent atmospheric measurements, indicating that CO is well preserved in the firn at these sites. CO atmospheric history was reconstructed back to the year 1950 from the measurements using a combination of two forward models of gas transport in firn and an inverse model. The reconstructed history suggests that Arctic CO was already higher in 1950 than it is today. CO mole fractions rose gradually until the 1970s and peaked in the 1970s or early 1980s, followed by a decline to today's levels. We compare the CO history with the atmospheric histories of methane, light hydrocarbons, molecular hydrogen, CO stable isotopes and hydroxyl radical (OH), as well as with published CO emission inventories and results of a historical run from a chemistry-transport model. We find that the reconstructed Greenland CO history cannot be reconciled with available emission inventories unless large changes in OH are assumed. We argue that the available CO emission inventories chronically underestimate NH emissions, and fail to capture the emission decline starting in the late 1970s, which was most likely due to reduced emissions from road transportation in North America and Europe.
The impact of a future H2-based road transportation sector on the composition and chemistry of the atmosphere – Part 1: Tropospheric composition and air quality
Authors: Wang D. , Jia W. , Olsen S. C. , Wuebbles D. J. , Dubey M. K. , Rockett A. A.
Published: August 2012

Abstract. Vehicles burning fossil fuel emit a number of substances that change the composition and chemistry of the atmosphere, and contribute to global air and water pollution and climate change. For example, nitrogen oxides and volatile organic compounds (VOCs) emitted as byproducts of fossil fuel combustion are key precursors to ground-level ozone and aerosol formation. In addition, on-road vehicles are major CO2 emitters. In order to tackle these problems, molecular hydrogen (H2) has been proposed as an energy carrier to substitute for fossil fuel in the future. However, before implementing any such strategy it is crucial to evaluate its potential impacts on air quality and climate. Here we evaluate the impact of a future (2050) H2-based road transportation sector on tropospheric chemistry and air quality for several possible growth and technology adoption scenarios. The growth scenarios are based on the high and low emissions Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios, A1FI and B1, respectively. The technological adoption scenarios include H2 fuel cell and H2 internal combustion engine options. The impacts are evaluated with the Community Atmospheric Model Chemistry global chemistry transport model (CAM-Chem). Higher resolution simulations focusing on the contiguous United States are also carried out with the Community Multiscale Air Quality Modeling System (CMAQ) regional chemistry transport model. For all scenarios future air quality improves with the adoption of a H2-based road transportation sector, however, the magnitude and type of improvement depend on the scenario. Model results show that with the adoption of H2 fuel cells decreases tropospheric burdens of ozone (7%), CO (14%), NOx (16%), soot (17%), sulfate aerosol (4%), and ammonium nitrate aerosol (12%) in the A1FI scenario, and decreases those of ozone (5%), CO (4%), NOx (11%), soot (7%), sulfate aerosol (4%), and ammonium nitrate aerosol (9 %) in the B1 scenario. The adoption of H2 internal combustion engines decreases tropospheric burdens of ozone (1%), CO (18%), soot (17%), and sulfate aerosol (3%) in the A1FI scenario, and decreases those of ozone (1%), CO (7%), soot (7%), and sulfate aerosol (3%) in the B1 scenario. In the future, people residing in the contiguous United States are expected to experience significantly fewer days of elevated levels of pollution if a H2 fuel cell road transportation sector is adopted. Health benefits of transitioning to a H2 economy for citizens in developing nations, like China and India, will be much more dramatic particularly in megacities with severe air-quality problems that are exacerbating.
Atmospheric ammonia and particulate inorganic nitrogen over the United States
Authors: Heald C. L. , Collett J. L. , Lee T. , Benedict K. B. , Schwandner F. M. , Li Y. , Clarisse L. , Hurtmans D. R. , Van Damme M. , Clerbaux C. , Coheur P.-F. , Pye H. O. T.
Published: August 2012

Abstract. We use in situ observations from the Interagency Monitoring of PROtected Visual Environments (IMPROVE) network, the Midwest Ammonia Monitoring Project, 11 surface site campaigns as well as Infrared Atmospheric Sounding Interferometer (IASI) satellite measurements with the GEOS-Chem model to investigate inorganic aerosol loading and atmospheric ammonia concentrations over the United States. IASI observations suggest that current ammonia emissions are underestimated in California and in the springtime in the Midwest. In California this underestimate likely drives the underestimate in nitrate formation in the GEOS-Chem model. However in the remaining continental United States we find that the nitrate simulation is biased high by a factor of 1.5 or more year-round. None of the uncertainties in precursor emissions, the uptake efficiency of N2O5 on aerosols, OH concentrations, the reaction rate for the formation of nitric acid, or the dry deposition velocity of nitric acid are able to explain this. We find that reducing nitric acid concentrations to 2/3 of their simulated values corrects the bias in nitrate (as well as ammonium) in the US. However the mechanism for this potential reduction is unclear and may be a combination of errors in chemistry, deposition and sub-grid near-surface gradients. This "updated" simulation reproduces PM and ammonia loading and captures the strong seasonal and spatial gradients in gas-particle partitioning across the United States. We estimate that nitrogen makes up 15–35% of inorganic fine PM mass over the US, and that this fraction is likely to increase in the coming decade, both with decreases in sulfur emissions and increases in ammonia emissions.
Carbon Cycle Uncertainty in REgional Carbon Cycle Assessment and Processes (RECCAP)
Authors: Enting I. G. , Rayner P. J. , Ciais P.
Published: August 2012

Abstract. Characterisation of estimates of regional carbon budgets and processes is inherently a statistical task. In full form this means that almost all quantities used or produced are realizations or instances of probability distributions. We usually compress the description of these distributions by using some kind of location parameter (e.g. the mean) and some measure of spread or uncertainty (e.g. the standard deviation). Characterising and calculating these uncertainties, and their structure in space and time, is as important as the location parameter, but uncertainties are both hard to calculate and hard to interpret. In this paper we describe the various classes of uncertainty that arise in a process like RECCAP and describe how they interact in formal estimation procedures. We also point out the impact these uncertainties will have on the various RECCAP synthesis activities.
Comparison of soil greenhouse gas fluxes from extensive and intensive grazing in a temperate maritime climate
Authors: Skiba U. , Jones S. K. , Drewer J. , Helfter C. , Anderson M. , Dinsmore K. , McKenzie R. , Nemitz E. , Sutton M. A.
Published: August 2012

Abstract. Greenhouse gas (GHG) fluxes from a seminatural, extensively sheep grazed drained moorland and intensively sheep grazed fertilised grassland in SE Scotland were compared over 4 yr (2007–2010). Nitrous oxide and CH4 fluxes were measured by static chambers, respiration from soil including ground vegetation by a flow through chamber and the net ecosystem exchange of CO2 by eddy covariance. All GHG fluxes displayed high temporal and interannual variability. Temperature, radiation, water table height and precipitation could explain a significant percentage of seasonal and interannual variations. Greenhouse gas fluxes were dominated by the net ecosystem exchange of CO2, emissions of N2O from the grazed grassland (384 g CO2eq m−2 yr−1) and emissions of CH4 from ruminant fermentation (147 g CO2eq m−2 yr−1). Methane emissions from the moorland were small (6.7 g CO2eq m−2 yr−1). Net ecosystem exchange of CO2 and respiration were much larger on the productive fertilised grassland (−1624 and +7157 g CO2eq m−2 yr−1, respectively) than the seminatural moorland (−338 and +2554 g CO2eq m−2 yr−1, respectively). Large CH4 and N2O losses from the grazed grassland counteracted the CO2 uptake by 35%, whereas the small N2O and CH4 emissions from the moorland did only impact the NEE by 2%.The 4 yr average GHG budget for the grazed grassland was 1006 g CO2eq m−2 yr−1 and 331 g CO2eq m−2 yr−1 for the moorland.
Spatiotemporal variability and long-term trends of ocean acidification in the California Current System
Authors: Hauri C. , Gruber N. , Vogt M. , Doney S. C. , Feely R. A. , Lachkar Z. , Leinweber A. , McDonnell A. M. P. , Munnich M. , Plattner G.-K.
Published: August 2012

Abstract. Due to seasonal upwelling, the upper ocean waters of the California Current System (CCS) have a naturally low pH and aragonite saturation state (Ωarag), making this region particularly prone to the effects of ocean acidification. Here, we use the Regional Oceanic Modeling System (ROMS) to conduct preindustrial and transient (1995–2050) simulations of ocean biogeochemistry in the CCS. The transient simulations were forced with increasing atmospheric pCO2 as projected by the NCAR CSM 1.4 model run under either the IPCC SRES A2 or B1 scenarios. Using ROMS, we investigate the timing of transition decades during which pH and Ωarag depart from their modeled preindustrial (1750) and present-day (2011) variability envelopes. We report these transition decades by noting the midpoint of the ten-year transition periods. In addition, we also analyze the timing of near permanent aragonite undersaturation in the upper 100 m of the water column. Our results show that an interplay of physical and biogeochemical processes create large seasonal variability in pH (∼ 0.14) and Ωarag (∼ 0.2). Despite this large variability, we find that present-day pH and Ωarag have already moved out of their preindustrial variability envelopes due to the rapidly increasing concentrations of atmospheric CO2. The simulations following the A2 emissions scenario suggest that nearshore surface pH of the northern and central CCS will move out of their present-day variability envelopes by 2045 and 2037, respectively. However, surface Ωarag of the northern and central CCS subregions are projected to depart from their present-day variability envelopes sooner, by 2030 and 2035, respectively. By 2025, the aragonite saturation horizon of the central CCS is projected to shoal into the upper 75 m for the duration of the annual cycle, causing near permanent undersaturation in subsurface waters. Overall, our study shows that the CCS joins the Arctic and Southern Oceans as one of only a few known ocean regions presently approaching this dual threshold of undersaturation with respect to aragonite and a departure from its variability envelope. In these regions, organisms may be forced to rapidly adjust to conditions that are both inherently chemically challenging and also substantially different from prior conditions.
On the gas-ice depth difference (Δdepth) along the EPICA Dome C ice core
Authors: Parrenin F. , Barker S. , Blunier T. , Chappellaz J. , Jouzel J. , Landais A. , Masson-Delmotte V. , Schwander J. , Veres D.
Published: August 2012

Abstract. We compare a variety of methods for estimating the gas/ice depth offset (Δdepth) at EPICA Dome C (EDC, East Antarctica). (1) Purely based on modelling efforts, Δdepth can be estimated combining a firn densification with an ice flow model. (2) The diffusive column height can be estimated from δ15N and converted to Δdepth using an ice flow model and assumptions about past average firn density and thickness of the convective zone. (3) Ice and gas synchronisation of the EDC ice core to the GRIP, EDML and TALDICE ice cores shifts the ice/gas offset problem into higher accumulation ice cores where it can be more accurately evaluated. (4) Finally, the bipolar seesaw hypothesis allows us to synchronise the ice isotopic record with the gas CH4 record, the later being taken as a proxy of Greenland temperature. The general agreement of method 4 with methods 2 and 3 confirms that the bipolar seesaw antiphase happened during the last 140 kyr. Applying method 4 to the deeper section of the EDC core confirms that the ice flow is complex and can help to improve our reconstruction of the thinning function and thus, of the EDC age scale. We confirm that method 1 overestimates the glacial Δdepth at EDC and we suggest that it is due to an overestimation of the glacial lock-in depth (LID) by the firn densification model. In contrast, we find that method 1 very likely underestimates Δdepth during Termination II, due either to an underestimated thinning function or to an underestimated LID. Finally, method 2 gives estimates within a few metres of methods 3 and 4 during the last deglacial warming, suggesting that the convective zone at Dome C cannot have been very large at this time, if it existed at all.
Preventive strategy in response to climate change and infrastructural failures for Jakarta slum dwellers
Authors: Pooroe V. , Prabaharyaka I.
Published: August 2012

Abstract. Jakarta is a city with unpredictable yet annual water shortages, both during the dry and wet season, which disproportionately affect the urban poor. One possible solution is to redevelop the existing water supply system which is now working in one of the largest slum area in Penjaringan, North Jakarta. This system is equipped with a large meter, the Master Meter, to record the communal water consumption and individual meters to record household consumptions. The Community Based Organization uses, operates, and maintains the system based on agreement with water users. Improvement of the Master Meter is achieved by harvesting uncollected rain water during the wet season with its high rainfall intensity, modifying the water storage system and improving the influent water quality. This paper aims to provide a preventive strategy in response to climate change and infrastructural failures based on a case study of community-based water supply project in Penjaringan, Jakarta.
Global high-resolution simulations of CO2 and CH4 using a NIES transport model to produce a priori concentrations for use in satellite data retrievals
Authors: Saeki T. , Saito R. , Belikov D. , Maksyutov S.
Published: August 2012

Abstract. The Greenhouse gases Observing SATellite (GOSAT) measures column-averaged dry air mole fractions of carbon dioxide and methane (XCO2 and XCH4, respectively). Since the launch of GOSAT, model-simulated three-dimensional concentrations from a National Institute for Environmental Studies offline tracer Transport Model (NIES TM) have been used as a~priori concentration data for retrieving XCO2 and XCH4 from GOSAT short-wavelength infrared spectra at NIES. Though a priori concentrations for retrievals are optional, more reliable concentrations are desirable. In this paper we describe the newly developed NIES TM that has been adapted to provide global and near real-time concentrations of CO2 and CH4 using a high-resolution meteorological dataset, the Grid Point Value (GPV) prepared by the Japan Meteorological Agency. The spatial resolution of the NIES TM is set to 0.5° × 0.5° in the horizontal in order to utilize GPV data, which have a resolution of 0.5° × 0.5°, 21 pressure levels, and a time interval of 3 h. GPV data are provided to the GOSAT processing system with a delay of several hours, and the near real-time model simulation produces a priori concentrations driven by diurnally varying meteorology. A priori variance–covariance matrices of CO2 and CH4 are also derived from the simulation outputs and observation-based reference data for each month of the year at a resolution of 0.5° × 0.5° and 21 pressure levels. Model performance is assessed by comparing simulation results with the GLOBALVIEW dataset and other observational data. The overall root-mean-square differences between model predictions and GLOBALVIEW analysis are estimated to be 2.28 ppm and 12.68 ppb for CO2 and CH4, respectively, and the seasonal correlation coefficients are 0.86 for CO2 and 0.61 for CH4. The model showed good performance particularly at oceanic and free tropospheric sites. The model also performs well in reproducing both the observed synoptic variations at some sites, and stratospheric profiles over Japan. These results give us confidence that the performance of our GPV-forced high-resolution NIES TM is adequate for use in satellite retrievals.
Moving university hydrology education forward with community-based geoinformatics, data and modeling resources
Authors: Merwade V. , Ruddell B. L.
Published: August 2012

Abstract. In this opinion paper, we review recent literature related to data and modeling driven instruction in hydrology, and present our findings from surveying the hydrology education community in the United States. This paper presents an argument that that data and modeling driven geoscience cybereducation (DMDGC) approaches are essential for teaching the conceptual and applied aspects of hydrology, as a part of the broader effort to improve science, technology, engineering, and mathematics (STEM) education at the university level. The authors have undertaken a series of surveys and a workshop involving university hydrology educators to determine the state of the practice of DMDGC approaches to hydrology. We identify the most common tools and approaches currently utilized, quantify the extent of the adoption of DMDGC approaches in the university hydrology classroom, and explain the community's views on the challenges and barriers preventing DMDGC approaches from wider use. DMDGC approaches are currently emphasized at the graduate level of the curriculum, and only the most basic modeling and visualization tools are in widespread use. The community identifies the greatest barriers to greater adoption as a lack of access to easily adoptable curriculum materials and a lack of time and training to learn constantly changing tools and methods. The community's current consensus is that DMDGC approaches should emphasize conceptual learning, and should be used to complement rather than replace lecture-based pedagogies. Inadequate online material publication and sharing systems, and a lack of incentives for faculty to develop and publish materials via such systems, is also identified as a challenge. Based on these findings, we suggest that a number of steps should be taken by the community to develop the potential of DMDGC in university hydrology education, including formal development and assessment of curriculum materials, integrating lecture-format and DMDGC approaches, incentivizing the publication by faculty of excellent DMDGC curriculum materials, and implementing the publication and dissemination cyberinfrastructure necessary to support the unique DMDGC digital curriculum materials.
Sensitivity of groundwater recharge using climatic analogues and HYDRUS-1D
Authors: Leterme B. , Mallants D. , Jacques D.
Published: August 2012

Abstract. The sensitivity of groundwater recharge to different climate conditions was simulated using the approach of climatic analogue stations, i.e. stations presently experiencing climatic conditions corresponding to a possible future climate state. The study was conducted in the context of a safety assessment of a future near-surface disposal facility for low and intermediate level short-lived radioactive waste in Belgium; this includes estimation of groundwater recharge for the next millennia. Groundwater recharge was simulated using the Richards based soil water balance model HYDRUS-1D and meteorological time series from analogue stations. This study used four analogue stations for a warmer subtropical climate with changes of average annual precipitation and potential evapotranspiration from −42% to +5% and from +8% to +82%, respectively, compared to the present-day climate. Resulting water balance calculations yielded a change in groundwater recharge ranging from a decrease of 72% to an increase of 3% for the four different analogue stations. The Gijon analogue station (Northern Spain), considered as the most representative for the near future climate state in the study area, shows an increase of 3% of groundwater recharge for a 5% increase of annual precipitation. Calculations for a colder (tundra) climate showed a change in groundwater recharge ranging from a decrease of 97% to an increase of 32% for four different analogue stations, with an annual precipitation change from −69% to −14% compared to the present-day climate.
Bench scale laboratory tests to analyze non-linear flow in fractured media
Authors: Cherubini C. , Giasi C. I. , Pastore N.
Published: August 2012

Abstract. The knowledge of flow phenomena in fractured rocks is very important for groundwater resources management in hydrogeological engineering. A critical emerging issue for fractured aquifers is the validity of the Darcian-type "local cubic law", which assumes a linear relationship between flow rate and pressure gradient to accurately describe flow patterns. Experimental data obtained under controlled conditions such as in a laboratory increase our understanding of the fundamental physics of fracture flow and allow us to investigate the presence of non-linear flow inside fractures that generates a substantial deviation from Darcy's law. In this study the presence of non-linear flow in a fractured rock formation has been analyzed at bench scale in laboratory tests. The effects of non-linearity in flow have been investigated by analyzing hydraulic tests on an artificially created fractured rock sample of parallelepiped (0.60 × 0.40 × 0.8 m) shape. The volumes of water passing through different paths across the fractured sample for various hydraulic head differences have been measured, and the results of the experiments have been reported as specific flow rate vs. head gradient. The experimental results closely match the Forchheimer equation and describe a strong inertial regime. The results of the test have been interpreted by means of numerical simulations. For each pair of ports, several steady-state simulations have been carried out varying the hydraulic head difference between the inlet and outlet ports. The estimated linear and non-linear Forchheimer coefficients have been correlated to each other and respectively to the tortuosity of the flow paths. A correlation among the linear and non-linear Forchheimer coefficients is evident. Moreover, a tortuosity factor that influences flow dynamics has been determined.
Irrigania – a web-based game about sharing water resources
Authors: Seibert J. , Vis M. J. P.
Published: August 2012

Abstract. For teaching about collaboration and conflicts with regard to shared water resources, various types of games offer valuable opportunities. Single-player computer games often give much power to the player and ignore the fact that the best for some group might be difficult to achieve in reality if the individuals have their own interests. Here we present a new game called Irrigania, which aims at representing water conflicts among several actors in a simplified way. While simple in its rules, this game illustrates several game-theoretical situations typical for water-related conflicts. The game has been implemented as a web-based computer game, which allows easy application in classes. First classroom applications of the game indicated that, despite the simple rules, interesting patterns can evolve when playing the game in a class. These patterns can be used to discuss game theoretical considerations related to water resource sharing.
Thermal structure and intermediate-depth seismicity in the Tohoku-Hokkaido subduction zones
Authors: van Keken P. E. , Kita S. , Nakajima J.
Published: August 2012

Abstract. The cause of intermediate-depth (> 40 km) seismicity in subduction zones is not well understood. The viability of proposed mechanisms, that include dehydration embrittlement, shear instabilities, and the presence of fluids in general, depends significantly on local conditions, including pressure, temperature and composition. The well-instrumented and well-studied subduction zone below Northern Japan (Tohoku and Hokkaido) provides an excellent testing ground to study the conditions under which intermediate-depth seismicity occurs. This study combines new high resolution finite elements models that predict the dynamics and thermal structure of the Japan subduction system with a high precision hypocenter data base. The upper plane of seismicity is principally contained in the crustal portion of the subducting slab and appears to thin and deepen within the crust at depths > 80 km. The disappearance of seismicity overlaps in most of the region with the predicted phase change of blueschist to hydrous eclogite, which forms a major dehydration front in the crust. The correlation between thermally predicted blueschist-out boundary and the disappearance of seismicity breaks down in the transition from the northern Japan to Kurile arc below western Hokkaido. Adjusted models, that take into account the seismically imaged modified upper mantle structure in this region, fail to adequately recover the correlation that is seen below Tohoku and eastern Hokkaido. We conclude that the thermal structure below Western Hokkaido is significantly affected by time-dependent, 3-D dynamics of the slab. This study generally supports the role of fluids in the generation of intermediate-depth seismicity.
The recent retreat of Mexican glaciers on Citlaltépetl Volcano detected using ASTER data
Authors: Cortés-Ramos J. , Delgado-Granados H.
Published: August 2012

Abstract. Satellite imagery and net radiation data collected between 2001 and 2007 for Citlaltépetl Volcano confirm the dramatic shrinkage of Glaciar Norte and the elimination of Jamapa and Chichimeco glacier tongues. The Glaciar Norte rapidly retreated between 2001 and 2002 while for 2007 this retreat decreases considerably. Jamapa and Chichimeco tongues disappeared by 2001 as compared to the geometry shown for 1958. The Glaciar Norte lost about 72% of its surface area between 1958 and 2007. Recently, the ice loss appears to be accelerating as evidenced by the 33% areal loss in just 6 yr between 2001 and 2007. At this shrinkage rate the glaciers would be gone from the volcano by the year 2020, which is decades earlier than previously estimated. The net radiation from ASTER images and the energy fluxes calculated via the meteorological data at the glacial surface show the close relationship between glacial shrinkage and surface energy balance. The magnitude of changes in the net radiation balance allows improved understanding of glacial retreat in Mexico.
Information Used to Decide on Retreatment of Exudative Age-Related Macular Degeneration with anti-VEGF in Clinical Practice
Authors: Manousaridis Kleanthis , Manjunath Vina , Talks James
Published: August 2012

Purpose.

To record the information used in order to make a retreatment decision in patients with exudative age-related macular degeneration (AMD) and to assess if an optical coherence tomography (OCT)–only follow-up clinic would suffice.

Methods.

Two hundred patients under treatment with intravitreal anti–vascular endothelial growth factor injections (anti-VEGF) for exudative AMD were included. Each patient had previously received at least 3 intravitreal anti-VEGF injections (loading dose) (range 3–24 injections). Clinicians seeing the patients beyond the third injection were asked to document the criteria used to make a retreatment decision.

Results.

Overall, in 171 (85.5%) cases the retreatment decision was based on OCT findings of intraretinal or subretinal fluid alone. Diagnosis of recurrence requiring treatment would have been missed in 12 cases (6%), if OCT-only data had been used and funduscopy or visual function criteria had been omitted. Decision was based solely on functional criteria in only 2% of the cases. The retreatment decision was based on evaluation of morphologic funduscopic or OCT criteria in 187 (93.5%) cases.

Conclusions.

With the increasing number of patients having follow-up after anti- VEGF treatment, efficient systems of follow-up are required. Although most retreatment decisions could have been made by qualitative assessment of OCT images alone, the examination has considerable limitations. Optical coherence tomography in combination with color fundus photography could serve as screening tools for a rational implementation of other invasive imaging techniques such as fundus fluorescein angiography and indocyanine green angiography in decision-making.
Entropy Analysis of Mixed Convective Magnetohydrodynamic Flow of a Viscoelastic Fluid over a Stretching Sheet
Authors: Butta Adnan S. , Munawara Sufian , Ali Asif , Mehmood Ahmer
Published: August 2012

In the present article, an investigation is made on entropy generated within a mixed convective magnetohydrodynamic flow of a viscoelastic fluid over a stretching sheet. In performing the analysis, it is assumed that the flow is steady, laminar, and fully developed. The governing equations for velocity and temperature fields are transformed into nonlinear ordinary differential equations by using suitable similarity transformations and are solved using the homotopy analysis method. The expressions for local entropy generation number Ns, average entropy [Ns]avg, Bejan number Be, and average Bejan number [Be]avg are obtained using the corresponding velocity and temperature data. A comprehensive parametric study is presented through graphs.
Planejamento familiar: perfil das usuárias de uma unidade de saúde de Curitiba
Authors: Fagundes Marciele Guimarães , Pires Tânia Maria Santos
Published: August 2012

Este estudo almejou levantar o perfil reprodutivo e de planejamento familiar e as ferramentas utilizadas para concepção e contracepção, em mulheres em idade reprodutiva, evidenciando a importância das ações educativas relacionadas ao assunto. A coleta de dados sobre o padrão sexual e reprodutivo foi realizada por meio de um questionário desenvolvido com 14 perguntas fechadas, e aplicado no período de outubro a dezembro de 2007 a 355 mulheres de 15 a 49 anos da área de abrangência de uma unidade de saúde do município de Curitiba. Observou-se, dentre as mulheres sexualmente ativas, que: 33,8% usavam pílula (dois terços menores de 30 anos), 25,1% foram submetidas à laqueadura (quase 90% com pelo menos 30 anos de idade), 9,5% usavam injetáveis, 10,5% utilizavam unicamente o preservativo e as demais tinham companheiros submetidos à vasectomia, usavam dispositivo intrauterino ou seguiam a ‘tabelinha’. 9,8% afirmavam não usar nenhum método e 79,8% não usavam preservativo. 40,5% das adolescentes sexualmente ativas utilizam preservativo. A maior fonte de aprendizado sobre anticoncepcionais são médicos ou enfermeiros (38,3%), enquanto sobre planejamento familiar são familiares (20,8%), embora 29% responderam que ninguém as teria ensinado a respeito. Aproximadamente três quartos das entrevistadas desejavam até dois filhos e 48,7% teriam dois filhos. Do somatório provável das gestações, 31,7% foram declaradas planejadas, aquém do esperado. A primeira gestação foi a com maior porcentagem de planejamento, 36,7%, das quais 71% ocorreram na idade adulta, seguida da segunda, com 32,5%. Mais de um terço não planejou gestação alguma. Um total de 37,5% de mulheres teve número de gestações que não extrapolam o desejado. A média estimada da menarca foi de 12,9 anos e 17% afirmaram sexarca até os 14 anos. Das não-nuligestas e com história de uso de anticoncepcionais, mais de um quarto começaram contracepção somente após a primeira gestação. Houve proporcionalmente mais gestações relatadas do que o número desejado de filhos, quanto menor o grau de instrução. Pode-se notar que o conhecimento do planejamento familiar ainda não está bem difundido e o percentual de gestações consideradas planejadas é baixo e menor que o esperado. A proposta é investir em orientações e atividades em saúde, desde os dez anos, em ações de planejamento familiar que garantam o aprendizado dos indivíduos e a escolha informada do casal em prol de sua própria família.
Uma experiência de psicoterapia de grupo dentro da Estratégia Saúde da Família
Authors: Abrahamian Roy
Published: August 2012

Este trabalho avaliou um Grupo de Saúde Mental desenvolvido na Estratégia Saúde da Família, baseado na análise transacional associada à terapia cognitivo-comportamental, descrevendo o impacto desta intervenção na melhoria da qualidade de vida da população atendida. Na Unidade Básica de Saúde Cruz das Almas, da Prefeitura de São Paulo, desde janeiro de 2007, realiza-se um grupo de Saúde Mental, com a frequência de uma vez por semana, com duração de uma hora. Neste grupo, os participantes discutem temas de seus interesses e aprendem técnicas de psicoterapia para lidarem com eventos do cotidiano e manejarem suas emoções e comportamentos de forma construtiva. O grupo é aberto aos interessados em participar das sessões de terapia, constituindo-se, em sua maioria, de pacientes acompanhados pelas equipes do Programa Saúde da Família e encaminhados ao Grupo de Saúde Mental. Ao ingressarem ao grupo, os pacientes preenchem o questionário sobre a saúde do(a) paciente, versão brasileira, conhecida pela sigla PHQ-9. Após frequentarem o grupo por, no mínimo, 12 sessões, os participantes preenchem um questionário de autoavaliação, informando sobre sua sensação de melhora em relação à sua saúde, melhora na autoestima e nos relacionamentos pessoais, e a visão mais positiva da vida e das outras pessoas. Dos participantes avaliados, 40 preencheram o questionário PHQ-9. Destes, nove (22,5%) tiveram pontuação de zero a quatro (sem depressão); seis (15%) tiveram pontuação de cinco a nove (depressão leve); dez (25%) tiveram pontuação de 10 a 14 (depressão moderada); sete (17,5%) tiveram pontuação de 15 a 19 (depressão moderada a grave); e oito (20%) tiveram pontuação de 20 ou mais (depressão grave). Dos 65 pacientes que responderam ao questionário de autoavaliação após pelo menos 12 sessões de terapia, 51 (78%) relataram visão mais positiva da vida e dos outros com a terapia; 44 (67%) referiram melhora da autoestima; 52 (80%), melhora nos relacionamentos e 53 (81%), melhora em relação à saúde. A melhora relatada pelos pacientes nas diversas áreas de suas vidas aponta para a importância desse tipo de abordagem dentro da Estratégia Saúde da Família, e para o impacto positivo da Psicoterapia baseada na Análise Transacional associada a técnicas cognitivo-comportamentais no tratamento de pacientes com transtornos mentais na Atenção Primária à Saúde.
Atuação da Estratégia Saúde da Família e do Núcleo de Apoio à Saúde da Família no uso racional de medicamentos em Rio Fortuna, em Santa Catarina
Authors: Omomo Fabio Tetsuo , Bechtold Tiago Michels
Published: August 2012

A atenção farmacêutica tem sido foco de grande preocupação principalmente no que diz respeito ao uso correto de medicamentos, automedicação, intoxicações, interações medicamentosas e efeitos adversos danosos à população. O presente trabalho teve como objetivo geral avaliar o uso racional de medicamentos junto à população de abrangência das equipes de saúde da família do município de Rio Fortuna, em Santa Catarina. Os objetivos específicos foram: informar a população sobre o problema do uso e abuso de medicamentos; avaliar a aceitação do debate sobre o tema; identificar polifarmácia domiciliar e o risco de abuso ou intoxicação medicamentosa, bem como servir de educação permanente em saúde aos trabalhadores do setor, e recolher medicamentos ociosos. Este é um estudo descritivo, transversal, quantiqualitativo, com dados coletados em inquérito domiciliar realizado por Agentes Comunitários de Saúde, além da realização de metodologia de educação permanente em saúde por meio de palestras e orientações do uso racional de medicamentos aplicados tanto para a equipe de saúde quanto à população. Foram realizadas 1.054 visitas a domicílios, sendo identificadas 185 famílias de risco quanto à presença de polifarmácia domiciliar. A média do consumo de medicamentos na população geral foi de dois a três comprimidos/habitante/dia, enquanto que, nas famílias em que havia polifarmácias, o consumo passou de nove a dez comprimidos por morador, por dia. Foram realizadas também 13 palestras educativas, ao final das quais aplicou-se questionário avaliativo da importância deste trabalho, no qual 98% dos participantes acharam importante a sua realização, 94% manifestaram que se sentiram mais informados a respeito do uso racional de medicamentos e 50% já praticaram a automedicação. Por meio deste trabalho, pode ter-se a percepção real da necessidade que a população tem do tratamento medicamentoso, muitas vezes sem orientação profissional e o limitado conhecimento dos riscos da automedicação e dos perigos das interações medicamentosas. Além disso, percebe-se que a atuação multiprofissional na atenção em saúde é essencial para o constante aprimoramento do cuidado da saúde e o entendimento de que a educação permanente em saúde, tanto dos profissionais quanto da população e da gestão setorial, pode promover grandes mudanças no paradigma assistencial.
Hepatitis C Virus, Cryoglobulinemia, and Kidney: Novel Evidence
Authors: Fabrizi Fabrizio
Published: August 2012

Hepatitis C virus infection can lead to chronic active hepatitis, cirrhosis, and liver failure; however, it is also associated with a wide range of extra-hepatic complications. HCV is associated with a large spectrum of histopathological lesions in both native and transplanted kidneys, and it is increasingly recognized as an instigator of B cell lympho-proliferative disorders including mixed cryoglobulinemia. Mixed cyoglobulinemia is a systemic vasculitis primarily mediated by immune complexes; it is characterized by variable organ involvement including skin lesions, chronic hepatitis, glomerulonephritis, peripheral neuropathy, and arthralgias. The most frequent HCV-associated nephropathy is type I membranoproliferative glomerulonephritis, usually in the context of type II mixed cryoglobulinemia. Various approaches have been tried for the treatment of HCV-related glomerulonephritis, including immunosuppressive therapy (corticosteroids and cytotoxic agents), plasma exchange and antiviral agents. Data on the antiviral treatment of HCV-associated glomerulonephritis are not abundant but encouraging results have been provided. Immunosuppressive therapy is particularly recommended for cryoglobulinemic kidney disease. Recent evidence has been accumulated on rituximab therapy for HCV-related cryoglobulinemic glomerulonephritis exists but several questions related to its use remain unclear. Distinct approaches should be considered for the treatment of HCV-associated cryoglobulinemic glomerulonephritis according to the level of proteinuria and kidney failure.
Subvertendo a cartografia escolar no Brasil
Authors: Seemann Jörn
Published: August 2012

O presente artigo apresenta idéias sobre como repensar a cartografia para a escola. Aportes filosóficos e teóricos para uma cartografia crítica na prática são propostos. O exemplo da arte com mapas é usado como ponto de partida para refletir sobre novos caminhos na disciplina. Essa abordagem alternativa do estudo de mapas é ilustrado através de diversos exemplos da sala de aula (exercícios com mapas mentais, imagens na internet e a leitura crítica de livros didáticos de geografia). Argumenta-se que a cartografia não serve apenas para fazer a guerra, mas também para formar cidadãos.Palavras-chave: cartografia crítica; mapas na arte; cartografia na sala de aula.DOI: 10.7147/GEO12.3191
Reflexão e construção de um projeto de ensino de Cartografia no contexto da Proposta Curricular de Geografia da rede municipal de educação de Juiz de Fora
Authors: De Aguiar Valéria Trevizani Burla
Published: August 2012

O objetivo deste estudo é o de apresentar as reflexões e propostas desenvolvidas acerca da educação cartográfica no contexto da elaboração do currículo que está proposto para o ensino fundamental da rede pública municipal de Juiz de Fora – MG.Palavras-chave: Educação Cartográfica, Educação Geográfica, Currículo Escolar DOI: 10.7147/GEO12.3197