scholarly journals CLABAUTAIR: a new algorithm for retrieving three-dimensional cloud structure from airborne microphysical measurements

2004 ◽  
Vol 4 (6) ◽  
pp. 8609-8625 ◽  
Author(s):  
R. Scheirer ◽  
S. Schmidt
Keyword(s):  
Three Dimensional ◽  
Lower Troposphere ◽  
Dimensional Structure ◽  
East Anglia ◽  
Airborne Measurements ◽  
Microphysical Parameters ◽  
Large Eddy ◽  
Measured Probability ◽  
Dimensional Distribution

Abstract. A new algorithm is presented to retrieve the three-dimensional structure of clouds from airborne measurements of microphysical parameters. Data from individual flight legs are scanned for characteristic patterns, and the autocorrelation functions for several directions are used to extrapolate the observations along the flight path to a full three-dimensional distribution of the cloud field. Thereby, the mean measured profiles of microphysical parameters are imposed to the cloud field by mapping the measured probability density functions onto the model layers. The algorithm was tested by simulating flight legs through synthetic clouds (by means of Large Eddy Simulations (LES)) and applied to a stratocumulus cloud case measured during the first field experiment of the EC project INSPECTRO (INfluence of clouds on the SPECtral actinic flux in the lower TROposphere) in East Anglia, UK. The number and position of the flight tracks determine the quality of the retrieved cloud field. If they provide a representative sample of the entire field, the derived pattern closely resembles the statistical properties of the real cloud field.

scholarly journals CLABAUTAIR: a new algorithm for retrieving three-dimensional cloud structure from airborne microphysical measurements

2005 ◽  
Vol 5 (9) ◽  
pp. 2333-2340 ◽  
Author(s):  
R. Scheirer ◽  
S. Schmidt
Keyword(s):  
Three Dimensional ◽  
Lower Troposphere ◽  
Dimensional Structure ◽  
East Anglia ◽  
Airborne Measurements ◽  
Microphysical Parameters ◽  
Large Eddy ◽  
Measured Probability ◽  
Dimensional Distribution

Abstract. A new algorithm is presented to reproduce the three-dimensional structure of clouds from airborne measurements of microphysical parameters. Data from individual flight legs are scanned for characteristic patterns, and the autocorrelation functions for several directions are used to extrapolate the observations along the flight path to a full three-dimensional distribution of the cloud field. Thereby, the mean measured profiles of microphysical parameters are imposed to the cloud field by mapping the measured probability density functions onto the model layers. The algorithm was tested by simulating flight legs through synthetic clouds (by means of Large Eddy Simulations (LES)) and applied to a stratocumulus cloud case measured during the first field experiment of the EC project INSPECTRO (INfluence of clouds on the SPECtral actinic flux in the lower TROposphere) in East Anglia, UK. The number and position of the flight tracks determine the quality of the retrieved cloud field. If they provide a representative sample of the entire field, the derived pattern closely resembles the statistical properties of the real cloud field.

scholarly journals An Initiation Process of Tropical Depression-type Disturbances under the Influence of Upper-level Troughs

2021 ◽  
Author(s):  
Yuya Hamaguchi ◽  
Yukari N. Takayabu
Keyword(s):  
Large Scale ◽  
Convective Available Potential Energy ◽  
Three Dimensional ◽  
Lower Troposphere ◽  
Dimensional Structure ◽  
Convective Heating ◽  
Upper Troposphere ◽  
Tropical Depression ◽  
Upper Level ◽  
Extratropical Forcing

AbstractIn this study, the statistical relationship between tropical upper-tropospheric troughs (TUTTs) and the initiation of summertime tropical-depression type disturbances (TDDs) over the western and central North Pacific is investigated. By applying a spatiotemporal filter to the 34-year record of brightness temperature and using JRA-55 reanalysis products, TDD-event initiations are detected and classified as trough-related (TR) or non-trough-related (non-TR). The conventional understanding is that TDDs originate primarily in the lower-troposphere; our results refine this view by revealing that approximately 30% of TDDs in the 10°N-20°N latitude ranges are generated under the influence of TUTTs. Lead-lag composite analysis of both TR- and non-TR-TDDs clarifies that TR-TDDs occur under relatively dry and less convergent large-scale conditions in the lower-troposphere. This result suggests that TR-TDDs can form in a relatively unfavorable low-level environment. The three-dimensional structure of the wave activity flux reveals southward and downward propagation of wave energy in the upper troposphere that converges at the mid-troposphere around the region where TR-TDDs occur, suggesting the existence of extratropical forcing. Further, the role of dynamic forcing associated with the TUTT on the TR-TDD-initiation is analyzed using the quasi-geostrophic omega equation. The result reveals that moistening in the mid-to-upper troposphere takes place in association with the sustained dynamical ascent at the southeast side of the TUTT, which precedes the occurrence of deep convective heating. Along with a higher convective available potential energy due to the destabilizing effect of TUTTs, the moistening in the mid-to-upper troposphere also helps to prepare the environment favorable to TDDs initiation.

scholarly journals Reconstruction of crystal shapes by X-ray nanodiffraction from three-dimensional superlattices

2014 ◽  
Vol 47 (6) ◽  
pp. 2030-2037 ◽  
Author(s):  
Mojmír Meduňa ◽  
Claudiu V. Falub ◽  
Fabio Isa ◽  
Daniel Chrastina ◽  
Thomas Kreiliger ◽  
...  
Keyword(s):  
Structural Model ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Semiconductor Layer ◽  
Dimensional Structure ◽  
Solid State Lasers ◽  
X Ray ◽  
Nondestructive Imaging ◽  
Low Dimensional

Quantitative nondestructive imaging of structural properties of semiconductor layer stacks at the nanoscale is essential for tailoring the device characteristics of many low-dimensional quantum structures, such as ultrafast transistors, solid state lasers and detectors. Here it is shown that scanning nanodiffraction of synchrotron X-ray radiation can unravel the three-dimensional structure of epitaxial crystals containing a periodic superlattice underneath their faceted surface. By mapping reciprocal space in all three dimensions, the superlattice period is determined across the various crystal facets and the very high crystalline quality of the structures is demonstrated. It is shown that the presence of the superlattice allows the reconstruction of the crystal shape without the need of any structural model.

scholarly journals Subgrid Parameterizations of the Eddy–Eddy, Eddy–Mean Field, Eddy–Topographic, Mean Field–Mean Field, and Mean Field–Topographic Interactions in Atmospheric Models

2019 ◽  
Vol 76 (2) ◽  
pp. 457-477 ◽  
Author(s):  
Vassili Kitsios ◽  
Jorgen S. Frederiksen
Keyword(s):  
Baroclinic Instability ◽  
Mean Field ◽  
Three Dimensional ◽  
Computational Effort ◽  
Atmospheric Flows ◽  
Large Eddy ◽  
Subgrid Scales ◽  
High Level ◽  
Jet Structure

Abstract Parameterizations are developed for each of the subgrid turbulence interaction classes in fully three-dimensional global atmospheric flows over topography, typical of January and July climate states. Stochastic and deterministic parameterizations are developed for the eddy–eddy interactions and deterministic parameterizations for eddy–mean field, eddy–topographic, mean field–mean field, and mean field–topographic interactions. All parameterizations are calculated from the statistics of higher-resolution reference direct numerical simulations (DNSs) truncated into resolved and subgrid scales and employed without tuning coefficients. This parameterization framework is validated by performing large-eddy simulations (LESs) that closely agree with the reference DNSs in terms of time-averaged kinetic energy spectra, zonal jet structure, and nonzonal streamfunction fields. Both the DNSs and LESs are formulated in such a way that the usual problem of a long artificial dissipation range does not occur. Successful LESs are produced with truncation wavenumbers 31 and 15, using, respectively, only 11.9% and 1.3% of the DNS computational effort at truncation wavenumber 63. The lower-resolution LESs show that the parameterizations are successful even when the energy injection due to baroclinic instability is not completely resolved. The contribution of each of the parameterized interaction classes to the quality of the LES is identified. The best agreement is achieved when all subgrid components are included. There is a very high level of agreement between the LESs and DNSs with typical streamfunction pattern correlations of r = 0.962 for the nonzonal components and r = 0.999 for the total fields when the complete sets of parameterizations are used.

scholarly journals Large-Eddy Simulation of a microburst

2011 ◽  
Vol 11 (17) ◽  
pp. 9323-9331 ◽  
Author(s):  
V. Anabor ◽  
U. Rizza ◽  
E. L. Nascimento ◽  
G. A. Degrazia
Keyword(s):  
Large Eddy Simulation ◽  
Three Dimensional ◽  
Leading Edge ◽  
Dimensional Structure ◽  
Ring Vortex ◽  
Surface Winds ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Strong Winds ◽  
Complex Phenomena

Abstract. The three-dimensional structure and evolution of an isolated and stationary microburst are simulated using a time-dependent, high resolution Large-Eddy-Simulation (LES) model. The microburst is initiated by specifying a simplified cooling source at the top of the domain around 2 km a.g.l. that leads to a strong downdraft. Surface winds of the order of 30 m s−1 were obtained over a region of 500 m radius around the central point of the impinging downdraft, with the simulated microburst lasting for a few minutes. These characteristic length and time scales are consistent with results obtained from numerical simulations of microbursts using cloud-resolving models. The simulated flow replicated some of the principal features of microbursts observed by Doppler radars: in particular, the horizontal spread of strong surface winds and a ring vortex at the leading edge of the cold outflow. In addition to the primary surface outflow, the simulation also generated a secondary surge of strong winds that appears to represent a pulsation in the microburst evolution. These results highlight the capability of LES to reproduce complex phenomena like microbursts, indicating the potential usage of LES models to represent atmospheric phenomena of time and space scales between the convective scale and the microscale. These include short-lived convectively-generated damaging winds.

Perceptions des aidant(e)s de la qualité des soins et des services en unités de courte durée gériatriques: Développement et validation d'un outil de mesure

2001 ◽  
Vol 20 (2) ◽  
pp. 251-270
Author(s):  
Danièle Roberge ◽  
Slim Haddad ◽  
Francine Ducharme ◽  
Paule Lebel ◽  
Raynald Pineault ◽  
...  
Keyword(s):  
Quality Of Care ◽  
Three Dimensional ◽  
Measurement Scale ◽  
Dimensional Structure ◽  
Global Index ◽  
Qualité Des Soins ◽  
Loved One ◽  
Good Internal Consistency ◽  
Points Of View

ABSTRACTThe goal of this study is to develop and validate a tool for measuring perceptions of caregivers of the quality of care and services in Geriatric Assessment Units. It has been designed so as to reproduce the notion of quality for caregivers. The validation of the tool is based on analyses of responses provided by caregivers (n = 274) to questions of perceived quality and to a certain number of questions necessary for the evaluation of its metric qualities. The measurement scale developed includes 25 items and it demonstrates good internal consistency. The Alpha Cronbach coefficients are 0.95 for the global index and they range from 0.88 to 0.91 on the sub-scales. The various analyses support a three-dimensional structure of the notion of quality for caregivers, explaining 66 per cent of the total variance. These dimensions are: “exchanges with professionals on the relative's condition,” “care given to a loved one,” and “planning the discharge”. It is hoped that this tool will promote the inclusion of the points of view of caregivers in the process of the improvement and assessment of quality.

scholarly journals Z-score to evaluate the absolute quality of macromolecular models based on SAXS data

2018 ◽  
Author(s):  
Dmytro Guzenko ◽  
Sergei V. Strelkov
Keyword(s):  
Goodness Of Fit ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Statistical Criterion ◽  
Biological Macromolecules ◽  
Z Score ◽  
Saxs Data ◽  
X Ray Scattering ◽  
Saxs Curve

Small-angle X-ray scattering (SAXS) is a highly popular technique to assess the native three-dimensional structure of biological macromolecules in solution. Here we introduce a statistical criterion, Z-score, as a novel quality measure of SAXS-based structural models which positively correlates with data quality. We propose that, besides a goodness-of-fit (GOF) measure such as reduced χ2, the Z-score reflecting the ability of a given SAXS curve to differentiate between possible models should always be reported.

The dimensional structure of transparency: A construct validation of transparency as disclosure, clarity, and accuracy in organizations

2020 ◽  
pp. 001872672093331
Author(s):  
Andrew K Schnackenberg ◽  
Edward Tomlinson ◽  
Corinne Coen
Keyword(s):  
Information Disclosure ◽  
Construct Validation ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Practical Application ◽  
Quality Of Information ◽  
Informational Justice ◽  
Research Traditions ◽  
Advance Research

In this article, we advance research on transparency by developing and validating a measure based on recent theoretical insights about its dimensionality. We find that transparency—defined as the perceived quality of information—is a three-dimensional construct consisting of perceived information disclosure, clarity, and accuracy. Evidence shows items associated with these dimensions can be aggregated into a single transparency construct. We also find that transparency (as an aggregate construct) is distinct from neighboring constructs such as informational justice and capable of predicting perceptions of the source’s trustworthiness (ability, benevolence, and integrity). Finally, we find evidence of measurement invariance between two commonly used referents of analysis, yielding confidence in the application of the proposed measure across research settings. We discuss implications of the new measure for research on transparency, the extension of the new measure to related research traditions, and the practical application of the new measure for managers interested in constructing and appraising transparent messages.

scholarly journals Structure-texture peculiarities influence on petrophysical properties of Neftekumsk carbonate sediments

2020 ◽  
Vol 164 ◽  
pp. 01007
Author(s):  
Natalia Yeriomina ◽  
Vladimir Gridin ◽  
Zinaida Sterlenko ◽  
Yelena Tumanova ◽  
Katerina Chernenko
Keyword(s):  
Pore Space ◽  
Three Dimensional ◽  
Carbonate Sediments ◽  
Petrophysical Properties ◽  
Petrophysical Parameters ◽  
The Core ◽  
Geological Models ◽  
Dimensional Distribution

The analysis of structure-texture peculiarities of carbonate sediments of Neftekumsk’ reservoir within the limits of Zimne-Stavkinsko- Pravoberezhny field was realized in the field of massive bioherm buildups and interreef lowerings in accordance with data of the core analyses. The existing pore space was divided into structure-texture classes. The correlations between petrofabrics and petrophysical parameters were determined. The received data can be used for describing of the three- dimensional distribution of petrophysical properties with the aim to increase the quality of three-dimensional (3-D) geological models.

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