bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of Air Quality in the Southeastern Hampton–Norfolk–Virginia Beach Region with Airborne Lidar Measurements and MODIS Aerosol Optical Depth Retrievals
Authors: Lewis Jasper , De Young Russell , Chu D. Allen 
Published: August 2009

Abstract
A study of air quality was performed using a compact, aircraft aerosol lidar designed in the Science Directorate at NASA Langley Research Center and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD) retrievals. Five flights of lidar measurements conducted in the Hampton–Norfolk–Virginia Beach, Virginia, region showed complex regional aerosol distributions. Comparisons with MODIS AOD at 10 km × 10 km and 5 km × 5 km resolutions show good agreement, with correlation R2 values of 0.82 and 0.88, respectively. Linear regressions of particulate matter with a diameter of less than 2.5 μm (PM2.5) and AOD within the ranges of 5–40 μg m−3 and 0.05–0.7, respectively, result in R2 values of ∼0.64 and ∼0.82 for MODIS and the Compact Aerosol Lidar, respectively. The linear regressions reflect approximately 51 μg m−3 to 1 AOD. These relationships are in agreement with previous findings for air pollution aerosols in the eastern United States and in northern Italy. However, large vertical variation is seen case by case, with planetary boundary layer heights ranging between 0.7 and 2 km and uncertainties ranging between 0.1 and 0.4 km. The results of the case studies suggest that AOD can be used as an indicator of surface measurements of PM2.5 but with larger uncertainties associated with small aerosol loading (AOD &lt; 0.3).
Modeling the Surface Energy Budget during the Thawing Period of the 2006 Montreal Urban Snow Experiment
Authors: Leroyer Sylvie , Mailhot Jocelyn , Bélair Stéphane , Lemonsu Aude , Strachan Ian B. 
Published: August 2009

AbstractThe Montreal Urban Snow Experiment was dedicated to furthering the understanding of micrometeorological processes involved in the late winter–early spring transition period in a Canadian city. A surface energy budget (SEB) measurement site was installed in a dense residential area of Montreal for several weeks in 2005 and 2006. This paper focuses on the last 6 days of the 2006 experiment (23–28 March 2006), after snowmelt and before vegetation became active, with the objectives of providing a better understanding of physical processes involved during this transition period and examining their impact on the SEB. The Town Energy Balance urban canopy model and the Interactions between Soil, Biosphere, and Atmosphere force–restore land surface model are used in stand-alone mode and are forced with meteorological data measured at the top of a 20-m AGL instrumented tower. Preliminary results reveal deficiencies in the models’ ability to simulate the surface energy budget partitioning, and in particular show overestimation of the sensible heat flux. Sensitivity studies indicate that a large portion of these problems is related to the latent heat transfer involved in natural soil freeze/thaw processes, which has a significant effect on the surface energy budget in this urban area. It is also found that the SEB in this particular situation is very sensitive to the thermal roughness length used for local energy exchange over the roof and road surfaces.
A Satellite-Based Assessment of Upper-Tropospheric Water Vapor Measurements during AFWEX
Authors: Chung Eui-Seok , Soden Brian J. 
Published: August 2009

Abstract
Consistency of upper-tropospheric water vapor measurements from a variety of state-of-the-art instruments was assessed using collocated Geostationary Operational Environmental Satellite-8 (GOES-8) 6.7-μm brightness temperatures as a common benchmark during the Atmospheric Radiation Measurement Program (ARM) First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE) Water Vapor Experiment (AFWEX). To avoid uncertainties associated with the inversion of satellite-measured radiances into water vapor quantity, profiles of temperature and humidity observed from in situ, ground-based, and airborne instruments are inserted into a radiative transfer model to simulate the brightness temperature that the GOES-8 would have observed under those conditions (i.e., profile-to-radiance approach). Comparisons showed that Vaisala RS80-H radiosondes and Meteolabor Snow White chilled-mirror dewpoint hygrometers are systemically drier in the upper troposphere by ∼30%–40% relative to the GOES-8 measured upper-tropospheric humidity (UTH). By contrast, two ground-based Raman lidars (Cloud and Radiation Test Bed Raman lidar and scanning Raman lidar) and one airborne differential absorption lidar agree to within 10% of the GOES-8 measured UTH. These results indicate that upper-tropospheric water vapor can be monitored by these lidars and well-calibrated, stable geostationary satellites with an uncertainty of less than 10%, and that correction procedures are required to rectify the inherent deficiencies of humidity measurements in the upper troposphere from these radiosondes.
A Statistical–Dynamical Estimate of Winter ENSO Teleconnections in a Future Climate
Authors: Schneider Edwin K. , Fennessy Michael J. , Kinter James L. 
Published: August 2009

Abstract
Changes in the atmospheric response to SST variability in the decade 2065–75 are estimated from time-slice-like experiments using the NCAR Community Atmosphere Model, version 3 (CAM3) AGCM forced by specified SST and external forcing. The current climate is simulated using observed monthly SST and external forcing for 1951–2000. The change in mean SST for the future is represented by the difference between the 2065–75 and 1965–75 decadal mean SST climatologies from coupled model twentieth-century/future climate simulations of the response to external forcing. The change in external forcing is similarly specified as the change of the external forcing concurrent with the SST change. These seasonally varying changes in SST and external forcing are added to the 50-year sequence of 1951–2000 observed SST and external forcings to produce the specified future climate forcings for the AGCM.
Changes in the December through February mean ENSO teleconnections are evaluated from the difference between ensemble means from future and current climate time slice simulations. The ENSO teleconnections are strengthened and displaced westward in the time slice simulations, which is not in agreement with CGCM projections. These changes are associated with increased precipitation/atmospheric heating anomalies due to the warmer tropical SST. The quasigeostrophic stationary wave activity flux indicates that the dominant cause of the changes is a southward shift in a midlatitude central Pacific wave activity source rather than changes in the basic-state stationary wave dispersion properties.
Nonlinear Effects of Tropical Instability Waves on the Equatorial Pacific Circulation
Authors: Brown Jaclyn N. , Godfrey J. Stuart , Wijffels Susan E. 
Published: August 2009

Abstract
In a numerical model of the equatorial Pacific Ocean, the ∼20-day period tropical instability waves, excited in the eastern half of the domain, are found to damp the strong zonal mean currents. The waves generate large, nonlinear, advection terms in the momentum balance, change the vorticity balance, and thus modulate the low-frequency state. The authors explore whether the effect of tropical instability waves on the background flow can instead be adequately parameterized by a constant-coefficient Laplacian friction scheme. On annual mean, a Laplacian friction coefficient that varies in space is required, for the coefficient is twice as large along the equator and a few degrees more to the north than elsewhere. In addition, wave activity varies in time. During active phases, such as the second half of the year and during La Niñas, the activity increases, which would require the Laplacian coefficient of friction to be at least twice as strong as during the inactive phases. Thus, a more sophisticated damping parameterization than simple Laplacian friction is required in ocean models that do not explicitly resolve tropical instability waves.
Wave Directions in a Narrow Bay
Authors: Pettersson Heidi , Kahma Kimmo K. , Tuomi Laura 
Published: August 2009

AbstractIn slanting fetch conditions the direction of actively growing waves is strongly controlled by the fetch geometry. The effect was found to be pronounced in the long and narrow Gulf of Finland in the Baltic Sea, where it significantly modifies the directional wave climate. Three models with different assumptions on the directional coupling between the wave components were used to analyze the physics responsible for the directional behavior of the waves in the gulf. The directionally decoupled model produced the direction at the spectral peak correctly when the slanting fetch geometry was narrow but gave a weaker steering than observed when the fetch geometry was broader. The method of Donelan estimated well the direction at the spectral peak in well-defined slanting fetch conditions, but overestimated the longer fetch components during wave growth from a more complex shoreline. Neither the decoupled nor the Donelan model reproduced the observed shifting of direction with the frequency. The performance of the third-generation spectral wave model (WAM) in estimating the wave directions was strongly dependent on the grid resolution of the model. The dominant wave directions were estimated satisfactorily when the grid-step size was dropped to 5 km in the gulf, which is 70 km in its narrowest part. A mechanism based on the weakly nonlinear interactions is proposed to explain the strong steering effect in slanting fetch conditions.
Vorticity from Line-of-Sight Lidar Velocity Scans
Authors: Weissmann Martin , Dörnbrack Andreas , Doyle James D. 
Published: August 2009

Abstract
A method is presented to compute the spanwise vorticity in polar coordinates from 2D vertical cross sections of high-resolution line-of-sight Doppler wind lidar observations. The method uses the continuity equation to derive the velocity component perpendicular to the observed line-of-sight velocity, which then yields the spanwise vorticity component. The results of the method are tested using a ground-based Doppler lidar, which was deployed during the Terrain-Induced Rotor Experiment (T-REX). The resulting fields can be used to identify and quantify the strength and size of vortices, such as those associated with atmospheric rotors. Furthermore, they may serve to investigate the dynamics and evolution of vortices and to evaluate numerical simulations. A demonstration of the method and comparison with high-resolution numerical simulations reveals that the derived vorticity can explain 66% of the mean-square vorticity fluctuations, has a reasonably skillful magnitude, exhibits no significant bias, and is in qualitative agreement with model-derived vorticity.
The Radiometric Sensitivity Requirements for Satellite Microwave Temperature Sounding Instruments for Numerical Weather Prediction
Authors: Bell William , Di Michele Sabatino , Bauer Peter , McNally Tony , English Stephen J. , Atkinson Nigel , Hilton Fiona , Charlton Janet 
Published: August 2009

Abstract
The sensitivity of NWP forecast accuracy with respect to the radiometric performance of microwave sounders is assessed through a series of observing system experiments at the Met Office and ECMWF. The observing system experiments compare the impact of normal data from a single Advanced Microwave Sounding Unit (AMSU) with that from an AMSU where synthetic noise has been added. The results show a measurable reduction in forecast improvement in the Southern Hemisphere, with improvements reduced by 11% for relatively small increases in radiometric noise [noise-equivalent brightness temperature (NEΔT) increased from 0.1 to 0.2 K for remapped data]. The impact of microwave sounding data is shown to be significantly less than was the case prior to the use of advanced infrared sounder data [Atmospheric Infrared Sounder (AIRS) and Infrared Atmospheric Sounding Interferometer (IASI)], with microwave sounding data now reducing Southern Hemisphere forecast errors by approximately 10% compared to 40% in the pre-AIRS/IASI period.
A Revised Tropical Cyclone Rapid Intensification Index for the Atlantic and Eastern North Pacific Basins
Authors: Kaplan John , DeMaria Mark , Knaff John A. 
Published: August 2009

Abstract
A revised rapid intensity index (RII) is developed for the Atlantic and eastern North Pacific basins. The RII uses large-scale predictors from the Statistical Hurricane Intensity Prediction Scheme (SHIPS) to estimate the probability of rapid intensification (RI) over the succeeding 24 h utilizing linear discriminant analysis. Separate versions of the RII are developed for the 25-, 30-, and 35-kt RI thresholds, which represent the 90th (88th), 94th (92nd), and 97th (94th) percentiles of 24-h overwater intensity changes of tropical and subtropical cyclones in the Atlantic (eastern North Pacific) basins from 1989 to 2006, respectively. The revised RII became operational at the NHC prior to the 2008 hurricane season.
The relative importance of the individual RI predictors is shown to differ between the two basins. Specifically, the previous 12-h intensity change, upper-level divergence, and vertical shear have the highest weights for the Atlantic basin, while the previous 12-h intensity change, symmetry of inner-core convection, and the difference in a system’s current and maximum potential intensity are weighted highest in the eastern North Pacific basin.
A verification of independent forecasts from the 2006 and 2007 hurricane seasons shows that the probabilistic RII forecasts are generally skillful in both basins when compared to climatology. Moreover, when employed in a deterministic manner, the RII forecasts were superior to all other available operational intensity guidance in terms of the probability of detection (POD) and false alarm ratio (FAR). Specifically, the POD for the RII ranged from 15% to 59% (53% to 73%) while the FAR ranged from 71% to 85% (53% to 79%) in the Atlantic (eastern North Pacific) basins, respectively, for the three RI thresholds studied. Nevertheless, the modest POD and relatively high FAR of the RII and other intensity guidance demonstrate the difficulty of predicting RI, particularly in the Atlantic basin.
Public Knowledge and Beliefs About Depression Among Urban and Rural Malays in Malaysia
Authors: Swami Viren , Loo Phik-Wern , Furnham Adrian 
Published: August 2009

Background: This study examined knowledge and beliefs about depression among Malaysian Malays varying in socioeconomic status. Methods: A total of 153 urban and 189 rural participants completed a questionnaire in which they had to identify two cases of depression and rate a series of items about the causes and best treatments for depression. Results: Results showed that urban participants were more likely to use psychiatric labels (‘depression’) for the two vignettes, whereas rural participants tended to use more generic terms (‘emotional stress’). Conclusion: Principal components analysis (PCA) showed that beliefs about the causes of depression factored into five components, of which stressful life events was most strongly endorsed by both groups. PCA of treatment items revealed four stable components, of which religious factors were most strongly endorsed. There were also a number of significant between-group differences in the endorsement of these factors (ηp2 = .03—.11), with rural participants generally rating supernatural and religious factors more strongly than urban Malays. These results are discussed in relation to mental health literacy programmes in Malaysia.
The Relationship Between General Population Suicide Rates and Mental Health Funding, Service Provision and National Policy: a Cross-National Study
Authors: Shah Ajit , Bhandarkar Ritesh , Bhatia Gurleen 
Published: August 2009

Objective: The main aims were to examine the relationship between general population suicide rates and the presence of national policies on mental health, funding for mental health, and measures of mental health service provision.Methods: Data on general population suicide rates for both genders were obtained from the World Health Organization (WHO) databank available on the WHO website. Data on the presence of national policies on mental health, funding for mental health and measures of mental health service provision were obtained from the Mental Health Atlas 2005, also available on the WHO website.Findings: The main findings were: (i) there was no relationship between suicide rates in both genders and different measures of mental health policy, except they were increased in countries with mental health legislation; (ii) there was a significant positive correlation between suicide rates in both genders and the percentage of the total health budget spent on mental health; and (iii) suicide rates in both genders were higher in countries with greater provision of mental health services, including the number of psychiatric beds, psychiatrists and psychiatric nurses, and the availability of training in mental health for primary care professionals.Conclusions: Cross-national ecological studies using national-level aggregate data are not helpful in establishing a causal relationship (and the direction of this relationship) between suicide rates and mental health funding, service provision and national policies. The impact of introducing national policies on mental health, increasing funding for mental health services and increasing mental health service provision on suicide rates requires further examination in longitudinal within-country studies.
Control Indications for an Inertial Drive Clutch Using Electro-Structured Fluid under Cyclic Operation
Authors: Johnson A. R. , Makin J. , Bullough W. A. 
Published: August 2009

The effects of various characteristics of an electro-structured fluid on the performance of a typical lightweight, high speed, flexibly operated inertial mechanism are investigated with a view to determining optimal matching of one to the other and as a basis from which to decide a control strategy. Values of the electron-hydraulic time delay and limiting yield stress of the fluid are varied between typical current values and those considered to be practically achievable within the next few years. The interplay of these with the viscosity of the fluid at zero excitation is shown.
Magnetorheological Fluids: Materials, Characterization, and Devices
Authors: Ashour Osama , Rogers Craig A. , Kordonsky William 
Published: August 2009

Magnetorheological (MR) fluids consist of stable suspensions of magnetic particles in a carrying fluid. Magnetorheological effect is one of the direct influences on the mechanical properties of a fluid. It represents a reversible increase, due to an external magnetic field of effective viscosity. MR fluids and devices have the potential to revolutionize the design of hydraulic systems, actuators, valves, active shock and vibration dampers, and other components used in mechanical systems. At present, there is a compelling need to develop new and improved MR fluids, to lower their production cost through improved manufacturing processes, and to develop MR fluid-based application devices that will demonstrate the engineering feasibility of the MR fluids concept and will highlight the implementation challenges. To this end, the present study is undertaken. A unique high-speed bead mill machine, especially designed to the manufacture of MR fluids, is used to fabricate MR fluids in a laboratory-scale MR fluid fabrication facility at the Center for Intelligent Material Systems and Structures (CIMSS) at VA Tech. Characterization studies are conducted to optimize the quality and the properties of MR fluids, and different ingredients and formulations are tested to produce MR fluids that meet most appropriately the design specifications. A modified HAAKE cone-plate viscometer is used to measure the basic properties of the manufactured MR fluids. As a demonstration of MR fluid-based devices, a cross-stepper exercise machine is modified to incorporate an MR throttle valve, which is the most important element of any MR fluid system.
Evaluation of Active Damping Performances in Orbit
Authors: Bousquet P. W. , Guay P. , Mercier F. 
Published: August 2009

The efforts dedicated to predicting and overcoming the vibrations of structures in space have increased dramatically over the last ten years. Motivating factors behind this increase are optical systems with high stability requirements, large antennas, sensitive microgravity payloads and compatibility of flexible appendages with attitude control. Prediction activities combine analytical model and ground tests to simulate the behaviour of structures. The requirements on structural dynamic transmissions often lead to specific developments in conception such as frequency decoupling with noise sources in the spacecraft, adding passive or active damping in the structural path, or setting up suspension devices. This paper focuses on the active damping involved in a truss structure which will be tested in the MIR station in 1996 within the frame of the CNES experiment CASTOR. This experiment aims at validating the analysis and test procedure for advanced space structure dynamic prediction, and demonstrating in zero gravity conditions the efficiency of passive and active damping technologies. After introducing the context, the paper is organised as follows: * objectives of CASTOR * design and optimisation of active damping system * test results * flight hardware and test plan * conclusion, further activities
Chemomechanical Gels for Actuator System Controlled by Electrochemical Reaction
Authors: Shinohara Shinobu , Tajima Nobuyoshi , Yanagisawa Kazuhisa 
Published: August 2009

We aim to make an actuator that uses the osmotic pressure of chemomechanical gels and is controlled by electrochemical reaction. This paper presents the preparation of the gels and measurement of pH change and gel actuation by the electrochemical reaction. Finally, we suggest one example of application suitable for gel actuator. The gels are made by photo-polymerization with ultraviolet irradiation to vinyl-monomers which are N,N'-dimethyl aminopropyl acrolamide (DMAPAA), Methylene-bis-acrylamide (MBAAM). Poly-vinyl alcohol (PVA) is added to the monomer solution to make the gels elastic. Swelling ratio and Young's modulus of the gels were measured in electrolyte solution with deferent pH and ion concentration. It became clear that the Young 's modulus of the gels increased with increasing the swelling ratio which was proportional to the osmotic pressure. This result is suitable for the actuator which uses the swelling pressure of the gels. The oxidizing and reducing agent for the electrochemical reaction is Ethyl Viologen Dibromide. The cell with the working electrode is separated from the cell with the counter one by an ion exchange membrane. The oxidation by applied potential of + 1.0 V decreases pH from 12 to 4 within 3 minutes. In the case of reduction, the potential of -0.8 V increases pH for 4 to 12 within the same minutes. The change of pH swells or shrinks the chemomechanical gels similar to adding acid or alkaline to the solution. Without stirring, it is difficult that pH change spreads into the gel completely in the short time, which causes the hysteresis. As the application of the gel actuator, a continuous dispenser is suggested and confirmed to discharge liquid from the balloon.