scholarly journals Performance of WVSS-II hygrometers on the FAAM Research Aircraft

2014 ◽  
Vol 7 (8) ◽  
pp. 8643-8667 ◽  
Author(s):  
A. K. Vance ◽  
S. J. Abel ◽  
R. J. Cotton ◽  
A. M. Woolley
Keyword(s):  
Liquid Water ◽  
The Other ◽  
Optimal Conditions ◽  
Statistical Assessment ◽  
Free Data ◽  
Variable Nature ◽  
Wide Range ◽  
Research Aircraft ◽  
Using Data ◽  
Good Agreement

Abstract. We compare the performance of five hygrometers fitted to the Facility for Airborne Atmospheric Measurement's (FAAM) BAe 146-301 research aircraft using data from approximately one hundred flights executed over the course of two years under a wide range of conditions. Bulk comparison of cloud free data show good agreement between chilled mirror hygrometers and a WVSS-II fed from a modified Rosemount inlet but that a WVSS-II fed from the standard flush inlet appears to over read compared to the other instruments, except at higher humidities. Statistical assessment of hygrometer performance in cloudy conditions is problematic due to the variable nature of clouds, so a number of case studies are used instead to investigate the performance of the hygrometers in sub optimal conditions. It is found that the flush inlet is not susceptible to either liquid or solid water but that the Rosemount inlet has a significant susceptibility to liquid water; it is not susceptible to ice. In all conditions the WVSS-II respond much more rapidly than the chilled mirror devices, with the flush inlet-fed WVSS-II being more rapid than that connected to the Rosemount.

scholarly journals Performance of WVSS-II hygrometers on the FAAM research aircraft

2015 ◽  
Vol 8 (3) ◽  
pp. 1617-1625 ◽  
Author(s):  
A. K. Vance ◽  
S. J. Abel ◽  
R. J. Cotton ◽  
A. M. Woolley
Keyword(s):  
Liquid Water ◽  
The Other ◽  
Optimal Conditions ◽  
Statistical Assessment ◽  
Free Data ◽  
Variable Nature ◽  
Wide Range ◽  
Research Aircraft ◽  
Using Data ◽  
Good Agreement

Abstract. We compare the performance of five hygrometers fitted to the Facility for Airborne Atmospheric Measurement's (FAAM) BAe 146-301 research aircraft using data from approximately 100 flights executed over the course of 2 years under a wide range of conditions. Bulk comparison of cloud free data show good agreement between chilled mirror hygrometers and a WVSS-II fed from a modified Rosemount inlet, but that a WVSS-II fed from the standard flush inlet appears to over-read compared to the other instruments, except at higher humidities. Statistical assessment of hygrometer performance in cloudy conditions is problematic due to the variable nature of clouds, so a number of case studies are used instead to investigate the performance of the hygrometers in sub-optimal conditions. It is found that the flush inlet is not susceptible to either liquid or solid water but that the Rosemount inlet has a significant susceptibility to liquid water and may also be susceptible to ice. In all conditions the WVSS-II responds much more rapidly than the chilled mirror devices, with the flush inlet-fed WVSS-II being more rapid than that connected to the Rosemount.

The Capacity for Rapid Shifts in Level of Mental Concentration

1972 ◽  
Vol 24 (4) ◽  
pp. 431-438 ◽  
Author(s):  
Gerald S. Blum ◽  
Marcia L. Porter
Keyword(s):  
The Other ◽  
Cognitive Tasks ◽  
Optimal Conditions ◽  
Cognitive Arousal ◽  
Wide Range

This investigation continues the exploration of a largely neglected topic in the field of attention, levels of mental concentration, by ascertaining under optimal conditions the capacity for shifting quickly from one level to another. Previous research in our laboratory had applied a set of five post-hypnotically cued levels of concentration or “cognitive arousal”, covering a very wide range, to a variety of perceptual and cognitive tasks. In the present study two highly trained undergraduate hypnotic subjects, one male and one female, were given progressively shorter time durations in which to respond to the post-hypnotic cues before viewing tachisto-scopically flashed consonants under cue influence. The results indicate a striking capacity to shift degrees of cognitive arousal very rapidly to one extreme or the other, on the order of 100 ms or less.

scholarly journals Modeling of Natural Convection in Electronic Enclosures

2005 ◽  
Vol 128 (2) ◽  
pp. 157-165 ◽  
Author(s):  
Peter M. Teertstra ◽  
M. Michael Yovanovich ◽  
J. Richard Culham
Keyword(s):  
Natural Convection ◽  
Numerical Data ◽  
Composite Model ◽  
Circuit Board ◽  
Flow Conditions ◽  
Transition Flow ◽  
Cfd Simulations ◽  
Wide Range ◽  
Using Data ◽  
Good Agreement

An analytical model is developed for natural convection from a single circuit board in a sealed electronic equipment enclosure. The circuit card is modeled as a vertical isothermal plate located at the center of an isothermal, cuboid shaped enclosure. A composite model is developed based on asymptotic solutions for three limiting cases: pure conduction, laminar boundary layer convection, and transition flow convection. The conduction shape factor and natural convection models are validated using data from CFD simulations for a wide range of enclosure geometries and flow conditions. The model is shown to be in good agreement, to within 10% RMS, with the numerical data for all test configurations.

Particle Resuspension in a Wall-Bounded Turbulent Flow

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
S. C. Fu ◽  
C. Y. H. Chao ◽  
R. M. C. So ◽  
W. T. Leung
Keyword(s):  
Angular Velocity ◽  
Uhlenbeck Process ◽  
Particle Resuspension ◽  
Air Stream ◽  
Safety And Health ◽  
Wide Range ◽  
Resuspension Rate ◽  
Mc Simulation ◽  
Using Data ◽  
Good Agreement

Resuspension is of common occurrence in a wide range of industrial and environmental processes. Excessive resuspension in these processes could have a severe impact on human safety and health. Therefore, it is necessary to develop a practical, yet reasonably accurate model to describe the resuspension phenomenon. It has been identified that rolling is the dominant mechanism for particle resuspension in the presence of an air stream, be it laminar or turbulent. Existing models predict the resuspension rate by regarding particles as being resuspended once they are set in motion; only a few of these models attempt to describe the full scenario, including rolling motion and the effect of turbulence. The objective of this paper is to propose a stochastic model to simulate the resuspension rate in the presence of a near-wall turbulent stream, and where the rolling mechanism is assumed to dominate the resuspension process. The fluctuating part of the angular velocity of a rolling particle is modeled by the Langevin equation (i.e., an Ornstein–Uhlenbeck process); thus, the overall angular velocity is modeled as a diffusion process. A free parameter of the proposed resuspension model is determined using data obtained from a Monte Carlo (MC) simulation of the problem. Once determined, the parameter is found to be universal for different materials and different sizes of particles tested. The modeling results obtained using this parameter are found to be in good agreement with experimental data, and the model performs better compared to other models.

scholarly journals Cloud<i>_</i>cci ATSR-2 and AATSR data set version 3: a 17-year climatology of global cloud and radiation properties

2020 ◽  
Vol 12 (3) ◽  
pp. 2121-2135
Author(s):  
Caroline A. Poulsen ◽  
Gregory R. McGarragh ◽  
Gareth E. Thomas ◽  
Martin Stengel ◽  
Matthew W. Christensen ◽  
...  
Keyword(s):  
Liquid Water ◽  
European Space Agency ◽  
Retrieval Algorithm ◽  
Transfer Model ◽  
Liquid Water Path ◽  
Data Set ◽  
Water Path ◽  
Cloud Properties ◽  
Wide Range ◽  
Good Agreement

Abstract. We present version 3 (V3) of the Cloud_cci Along-Track Scanning Radiometer (ATSR) and Advanced ATSR (AATSR) data set. The data set was created for the European Space Agency (ESA) Cloud_cci (Climate Change Initiative) programme. The cloud properties were retrieved from the second ATSR (ATSR-2) on board the second European Remote Sensing Satellite (ERS-2) spanning 1995–2003 and the AATSR on board Envisat, which spanned 2002–2012. The data are comprised of a comprehensive set of cloud properties: cloud top height, temperature, pressure, spectral albedo, cloud effective emissivity, effective radius, and optical thickness, alongside derived liquid and ice water path. Each retrieval is provided with its associated uncertainty. The cloud property retrievals are accompanied by high-resolution top- and bottom-of-atmosphere shortwave and longwave fluxes that have been derived from the retrieved cloud properties using a radiative transfer model. The fluxes were generated for all-sky and clear-sky conditions. V3 differs from the previous version 2 (V2) through development of the retrieval algorithm and attention to the consistency between the ATSR-2 and AATSR instruments. The cloud properties show improved accuracy in validation and better consistency between the two instruments, as demonstrated by a comparison of cloud mask and cloud height with co-located CALIPSO data. The cloud masking has improved significantly, particularly in its ability to detect clear pixels. The Kuiper Skill score has increased from 0.49 to 0.66. The cloud top height accuracy is relatively unchanged. The AATSR liquid water path was compared with the Multisensor Advanced Climatology of Liquid Water Path (MAC-LWP) in regions of stratocumulus cloud and shown to have very good agreement and improved consistency between ATSR-2 and AATSR instruments. The correlation with MAC-LWP increased from 0.4 to over 0.8 for these cloud regions. The flux products are compared with NASA Clouds and the Earth's Radiant Energy System (CERES) data, showing good agreement within the uncertainty. The new data set is well suited to a wide range of climate applications, such as comparison with climate models, investigation of trends in cloud properties, understanding aerosol–cloud interactions, and providing contextual information for co-located ATSR-2/AATSR surface temperature and aerosol products. The following new digital identifier has been issued for the Cloud_cci ATSR-2/AATSRv3 data set: https://doi.org/10.5676/DWD/ESA_Cloud_cci/ATSR2-AATSR/V003 (Poulsen et al., 2019).

Religion and Support for Democracy in Bosnia-Herzegovina

2012 ◽  
Vol 5 (3) ◽  
pp. 609-633
Author(s):  
Marko Valenta ◽  
Zan Strabac
Keyword(s):  
Negative Influence ◽  
The Other ◽  
The Political ◽  
World Values Survey ◽  
Political Sphere ◽  
Wide Range ◽  
Support For Democracy ◽  
Using Data ◽  
The Relationship ◽  
Different Levels

AbstractThis article examines the relationship between religiosity and support for democracy in Bosnia-Herzegovina. Using data from the last World Values Survey, we examine levels of religiosity among Bosniaks, Serbs, and Croats, and their support for democracy. The influence of religiosity on support for democracy is also explored. The results indicate that religiosity has a negative influence on support for democracy, and it is particularly true for individuals who do not support the separation of the religious from the political sphere and who exhibit lower support for democracy. The article also examines different levels of religiosity among the three groups, controlling for a wide range of variables. We conclude that there is basically no difference in support for democracy between Croats and Bosniaks, while Serbs exhibit somewhat lesser support for democracy than members of the other two ethnic groups. Serbs also seem to be somewhat less religious than Bosniaks and Croats. Opposition to separation of the religious from the political sphere is a major source of lack of support for democracy among Croats and Bosniaks, but not among Serbs.

Analytical Investigation of Glaciation Time in Mixed-Phase Adiabatic Cloud Volumes

2014 ◽  
Vol 71 (11) ◽  
pp. 4143-4157 ◽  
Author(s):  
M. Pinsky ◽  
A. Khain ◽  
A. Korolev
Keyword(s):  
Vertical Velocity ◽  
Liquid Water ◽  
Vertical Displacement ◽  
Liquid Water Content ◽  
Analytical Investigation ◽  
Mixed Phase ◽  
Liquid Droplets ◽  
Mass Balance Equation ◽  
Wide Range ◽  
Good Agreement

Abstract Glaciation in mixed-phase adiabatic cloudy parcels is investigated analytically using two new equations: the equation for coexistence of liquid water and ice and the mass balance equation. The analysis of glaciation time is performed for a vertically moving adiabatic mixed-phase cloud parcel. The effects of vertical velocity, liquid water content, and concentrations of ice particles, liquid droplets, temperature, and other parameters on the glaciation process are discussed. It is shown analytically that, for a certain envelope of vertical velocities, the glaciation time depends only on the vertical displacement of the parcel and does not depend on the trajectory along which the cloud parcel travels toward the glaciation point. Analytical dependencies of the glaciation time and of the altitude of glaciation on vertical velocity are presented. The results demonstrate a good agreement with those obtained using the corresponding parcel model. The limitations of the newly proposed approach are discussed as well, and it is shown that implementation of a simple correction factor allows one to calculate the glaciation time within a wide range of temperatures, from 0° down to −30°C.

New method and treatment technique applied to interband transition in GaAs1−x Px ternary alloys

Open Physics ◽  
2011 ◽  
Vol 9 (3) ◽  
Author(s):  
Cristina-Mihaela Băleanu ◽  
Raoul Nigmatullin ◽  
Saime Cetin ◽  
Dumitru Băleanu ◽  
Suleyman Ozcelik
Keyword(s):  
Room Temperature ◽  
Interband Transition ◽  
The Other ◽  
Ternary Alloys ◽  
New Method ◽  
Treatment Technique ◽  
Nonlinear Fitting ◽  
Wide Range ◽  
Fitting Parameters ◽  
Good Agreement

AbstractIn this paper we presented a new method (Eigen-Coordinates (ECs)) that can be used for calculations of the critical points (CPs) energy of the interband-transition edges of the heterostructures. This new method is more accurate and complete in comparison with conventional ones and has a wide range of application for the calculation of the fitting parameters related to nontrivial functions that initially have nonlinear fitting parameters that are difficult to evaluate. The new method was applied to determine the CPs energies from the dielectric functions of the MBE grown GaAs1−xPx ternary alloys obtained using spectroscopic ellipsometry (SE) measurements at room temperature in the 0.5-5 eV photon energy region. The obtained results are in good agreement with the results of the other methods.

scholarly journals Cloud_cci ATSR-2 and AATSR dataset version 3: a 17-yearclimatology of global cloud and radiation properties

2019 ◽  
Author(s):  
Caroline A. Poulsen ◽  
Gregory R. Mcgarragh ◽  
Gareth E. Thomas ◽  
Martin Stengel ◽  
Matthew W. Christiensen ◽  
...  
Keyword(s):  
Liquid Water ◽  
European Space Agency ◽  
Retrieval Algorithm ◽  
Transfer Model ◽  
Liquid Water Path ◽  
Water Path ◽  
Cloud Properties ◽  
Wide Range ◽  
Initiative Program ◽  
Good Agreement

Abstract. We present version 3 (V3) of the Cloud_cci ATSR-2/AATSR dataset. The dataset was created for the European Space Agency (ESA) Cloud_cci (Climate Change Initiative) program. The cloud properties were retrieved from the second Along- Track Scanning Radiometer (ATSR-2) on board the second European Remote Sensing Satellite (ERS-2) spanning 1995–2003 and the Advanced ATSR (AATSR) on board Envisat, which spanned 2002–2012. The data comprises a comprehensive set of cloud properties: cloud top height, temperature, pressure, spectral albedo, cloud effective emissivity, effective radius and optical thickness alongside derived liquid and ice water path. Each retrieval is provided with its associated uncertainty. The cloud property retrievals are accompanied by high-resolution top and bottom-of-atmosphere short- and long-wave fluxes that have been derived from the retrieved cloud properties using a radiative transfer model. The fluxes were generated for all-sky and clear-sky conditions. V3 differs from the previous version 2 (V2) through development of the retrieval algorithm and attention to the consistency between the ATSR-2 and AATSR instruments. The cloud properties show improved accuracy in validation and better consistency between the two instruments, as demonstrated by a comparison of cloud mask and cloud height with collocated CALIPSO data. The cloud masking has improved significantly, particularly the ability to detect clear pixels The Kuiper Skill score has increased from .49 to .66. The cloud top height accuracy is relatively unchanged. The AATSR liquid water path was compared with the Multisensor Advanced Climatology of Liquid Water Path (MAC-LWP) in regions of stratocumulous cloud and shown to have very good agreement and improved consistency between ATSR-2 and AATSR instruments, the Correlation with MAC-LWP increase from .4 to over .8 for these cloud regions. The flux products are compared with NASA Clouds and the Earth’s Radiant Energy System (CERES) data, showing good agreement within the uncertainty. The new dataset is well suited to a wide range of climate applications, such as comparison with climate models, investigation of trends in cloud properties, understanding aerosol-cloud interactions, and providing contextual information for collocated ATSR-2/AATSR surface temperature and aerosol products. For the Cloud_cci ATSR-2/AATSRv3 dataset a new digital identifier has been issued: https://doi.org/10.5676/DWD/ESA_Cloud_cci/ATSR2-AATSR/V003 Poulsen et al. (2019).

scholarly journals The Backscatter Cloud Probe – a compact low-profile autonomous optical spectrometer

2013 ◽  
Vol 6 (4) ◽  
pp. 7379-7424
Author(s):  
K. Beswick ◽  
D. Baumgardner ◽  
M. Gallagher ◽  
R. Newton
Keyword(s):  
Climate Models ◽  
The Other ◽  
Equivalent Diameter ◽  
Size Distributions ◽  
The European Union ◽  
Cloud Particle ◽  
Airborne Measurements ◽  
Cloud Properties ◽  
Wide Range ◽  
Research Aircraft

Abstract. A compact (500 cm3), lightweight (500 g), near-field, single particle backscattering optical spectrometer is described that mounts flush with the skin of an aircraft and measures the concentration and optical equivalent diameter of particles from 5 to 75 μm. The Backscatter Cloud Probe (BCP) was designed as a real-time qualitative cloud detector primarily for data quality control of trace gas instruments developed for the climate monitoring instrument packages that are being installed on commercial passenger aircraft as part of the European Union In-Service Aircraft for a Global Observing System (IAGOS) program (http://www.iagos.org/). Subsequent evaluations of the BCP measurements on a number of research aircraft, however, have revealed it capable of delivering quantitative particle data products including size distributions, liquid water content and other information on cloud properties. We demonstrate the instrument's capability for delivering useful long-term climatological information, across a wide range of environmental conditions. The BCP has been evaluated by comparing its measurements with those from other cloud particle spectrometers on research aircraft and several BCPs are currently flying on commercial A340/A330 Airbus passenger airliners. The design and calibration of the BCP is described in this presentation, along with an evaluation of measurements made on the research and commercial aircraft. Comparisons of the BCP with two other cloud spectrometers, the Cloud Droplet Probe (CDP) and the Cloud and Aerosol Spectrometer (CAS), show that the BCP size distributions agree well with those from the other two, given the intrinsic limitations and uncertainties related to the three instruments. Preliminary results from more than 7000 h of airborne measurements by the BCP on two Airbus A-340s operating on routine global traffic routes (one Lufthansa, the other China Airlines) show that more than 340 h of cloud data have been recorded at normal cruise altitudes (> 10 km) and more than 40% of the > 1200 flights were through clouds at some point between takeoff and landing. These data are a valuable contribution to data bases of cloud properties, including sub-visible cirrus, in the upper troposphere and useful for validating satellite retrievals of cloud water and effective radius as well as providing a broader, geographically and climatologically relevant view of cloud microphysical variability useful for improving parameterizations of clouds in climate models. They are also useful for monitoring the vertical climatology of clouds over airports, especially those over mega-cities where pollution emissions may be impacting local and regional climate.

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