A correlation for total band absorptance of radiating gases.
Single continuous correlation for total band absorptance of radiating gases
RADIATION ABSORPTION↗
SEARCH · Engineering Papers
Results for “total correlation”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
An analysis of tropopause pressure and total ozone correlations
A study of the relationship between total ozone and tropopause pressure was carried out using Total Ozone Mapping Spectrometer (TOMS) data and National Meteorological Center (NMC) global analyses. The medium scales generally show correlations greater than 0.6 throughout the middle latitudes of both hemispheres with some regions exceeding 0.8. The areas of highest correlations seem to be associated with the storm track regions of both the Northern and Southern Hemispheres. A detailed spectral analysis is performed for the medium scales on five pairs of time series of area averaged tropopause pressure and total ozone. In middle latitudes, total ozone and tropopause pressure exhibit generally similar distributions in the power spectrum. In the subtropics and tropics the power in ozone drops off more rapidly with increasing frequency than the power in tropopause pressure. Only in the Northern Hemisphere middle latitudes does one find a clear association between increased power in ozone and tropopause pressure and maxima in the coherency spectrum. Results for large scales are more complicated, showing generally positive correlations at middle latitudes.
Schubert, Siegfried D.↗
Correlation of total sound power and peak sideline OASPL from jet exhausts
An empirical analysis of jet noise is made for convergent exhaust nozzles. An engineering approach to the correlation of total sound power and miximum sideline overall sound pressure level (OASPL), at 200 ft, is presented for both subsonic and supersonic jets based on available data. Data correlation for subsonic jets shows no dependency of total sound power and maximum sideline OASPL on jet density. The analysis for supersonic jets results in a correlation parameter for jet total sound power consisting of the conventional Lighthill parameter modified by considerations of jet Mach number and jet acoustic velocity. Similar parameters also correlate the maximum sideline OASPL for supersonic jets.
Vonglahn, U. H.↗
Correlation of total sound power and peak sideline OASPL from jet exhausts.
An empirical analysis of jet noise is made for convergent exhaust nozzles. This study, conducted at the Lewis Research Center, presents an engineering approach to the correlation of total sound power and maximum sideline OASPL (at 200 ft) for both subsonic and supersonic jets based on available data. Data correlation for subsonic jets shows no dependency of total sound power and maximum sideline OASPL on jet density. The analysis for supersonic jets results in a correlation parameter for jet total sound power consisting of the conventional Lighthill parameter modified by considerations of jet Mach number and jet acoustic velocity. Similar parameters also correlate the maximum sideline OASPL for supersonic jets.
Von Glahn, U. H.↗
Correlation of total, diffuse, and direct solar radiation
Present requirements for realistic solar energy system evaluations necessitate a comprehensive body of solar-radition data. The data should include both diffuse and direct solar radiation as well as their total on an hourly (or shorter) basis. In general, however, only the total solar radiation values were recorded. This report presents a correlation that relates the diffuse component of an hourly total solar radiation value to the total radiation ratio of the maximum value attainable. The data used were taken at the Blue Hill Observatory in Milton, Massachusetts, for the period 1952. The relation - in the form of the data plots - can be used in situations in which only the hourly total radiation data are available but the diffuse component is desired.
Buyco, E. H.↗
Correlations of TOMS total ozone data (Nimbus-7 satellite) with tropopause height
Two correlation studies of Total Ozone Mapping Spectrometer (TOMS) data with tropopause height from radiosondes performed over Europe showed a correlation coefficient of 0.94 and 0.96. As a result, the rms error in the prediction of tropopause height from total ozone was found to be 20 mb. Correlation between tropopause height and TOMS data was the highest of all the other correlations with variables directly derived from radiosondes or simulated thermal radiances over the location of radiosondes. Comparing the two dimensional fields of TOMS, tropopause height from radiosondes and tropopause height field from TIROS-N retrievals, we can say that the first field is much closer to the true field from radiosondes than the third. The correlation coefficient for a ten-day study between TOMS data and tropopause height from radiosondes is between 0.85 and 0.9 for 30-70N. Tropopause analysis provided by GLA model also shows a very high correlation with TOMS data.
Munteanu, Marie-Jeanne↗
Simultaneous Retrievals of Biomass Burning Aerosols and Trace Gases From the Ultraviolet to Near-Infrared Over Northern Thailand During the 2019 Pre-Monsoon Season
With the advent of spaceborne spectroradiometers in a geostationary constellation, measuring high spectral resolution ultraviolet–visible (UV-VIS) and selected near-/shortwave-infrared (NIR/SWIR) radiances can enable the probing of the life cycle of key atmospheric trace gases and aerosols at higher temporal resolutions over the globe. The UV-VIS measurements are important for retrieving several key trace gases (e.g., O 3 , SO 2 , NO 2 , and HCHO) and particularly for deriving aerosol characteristics (e.g., aerosol absorption and vertical profile). This study examines the merit of simultaneous retrievals of trace gases and aerosols using a ground-based spectroradiometer covering the UV-NIR to monitor their physicochemical processes and to obtain reliable aerosol information for various applications. During the 2019 pre-monsoon season over northern Thailand, we deployed a ground-based SMART–s (Spectral Measurements for Atmospheric Radiative Transfer–spectroradiometer) instrument, which is an extended-range Pandora with reliable radiometric calibration in the 330–820 nm range, to retrieve remotely sensed chemical and aerosol properties for the first time near biomass burning sources. The high spectral resolution (∼ 1.0 nm full width half maximum with ∼ 3.7 × oversampling) of sun and sky measurements from SMART–s provides several key trace gases (e.g., O 3 , NO 2 , and H 2 O) and aerosol properties covering the UV where significant light absorption occurs by the carbonaceous particles. During the measurement period, highly correlated total column amounts of NO 2 and aerosol optical thickness (т aer ) retrieved from SMART–s (correlation coefficient, R=0.74) indicated their common emissions from biomass burning events. The SMART–s retrievals of the spectral single scattering albedo (ω 0 ) of smoke aerosols showed an abrupt decrease in the UV, which is an important parameter dictating photochemical processes in the atmosphere. The values of ω 0 and column precipitable water vapor (H 2 O) gradually increase with the mixing of biomass burning smoke particles and higher water vapor concentrations when approaching the monsoon season. The retrieved ω 0 and weighted mean radius of fine-mode aerosols from SMART–s showed positive correlations with the H 2 O (R=0.81 for ω 0 at 330 nm and 0.56 for the volume-weighted mean radius), whereas the real part of the refractive index of fine-mode aerosol (n f ) showed negative correlations (R = -0.61 at 330 nm), which suggest that aerosol aging processes including hygroscopic growth (e.g., humidification and cloud processing) can be a major factor affecting the temporal trends of aerosol optical properties. Retrieved n f and ω 0 were closer to those of the water droplet (i.e., n f of about 1.33 and ω 0 of about 1.0) under lower amounts of NO 2 during the measurement period; considering that the NO 2 amounts in the smoke may indicate the aging of the plume after emission due to its short lifetime, the tendency is also consistent with active hygroscopic processes of the aerosols over this area. Retrieved UV aerosol properties from SMART–s generally support the assumed smoke aerosol models (i.e., the spectral shape of aerosol absorption) used in NASA's current satellite algorithms, and their spectral ω 0 retrievals from ground and satellites showed good agreements (R = 0.73–0.79). However, temporal and spectral variabilities in the aerosol absorption properties in the UV emphasize the importance of a realistic optical model of aerosols for further improvements in satellite retrievals.
biomass burning↗
Three-dimensional boundary layer flow with streamwise adverse pressure gradient
The present study examines the effects of a strong adverse pressure gradient on a 3D turbulent boundary layer in an axisymmetric spinning cylinder geometry. Velocity measurements made with a three-component laser Doppler velocimeter include all three mean flow components, all six Reynolds stress components, and all ten triple-product correlations. Total Reynolds shear stress diminishes as the flow becomes 3D. Lower levels of shear stress were found to persist under adverse pressure gradient conditions. This low stress level was observed to roughly correlate with the magnitude of the crossflow. Variations in the pressure gradient do not alter this correlation. It is inferred that a 3D boundary layer is more prone to separate than a 2D boundary layer.
Driver, David M.↗
TACT: A Set of MSC/PATRAN- and MSC/NASTRAN- based Modal Correlation Tools
This paper describes the functionality and demonstrates the utility of the Test Analysis Correlation Tools (TACT), a suite of MSC/PATRAN Command Language (PCL) tools which automate the process of correlating finite element models to modal survey test data. The initial release of TACT provides a basic yet complete set of tools for performing correlation totally inside the PATRAN/NASTRAN environment. Features include a step-by-step menu structure, pre-test accelerometer set evaluation and selection, analysis and test result export/import in Universal File Format, calculation of frequency percent difference and cross-orthogonality correlation results using NASTRAN, creation and manipulation of mode pairs, and five different ways of viewing synchronized animations of analysis and test modal results. For the PATRAN-based analyst, TACT eliminates the repetitive, time-consuming and error-prone steps associated with transferring finite element data to a third-party modal correlation package, which allows the analyst to spend more time on the more challenging task of model updating. The usefulness of this software is presented using a case history, the correlation for a NASA Langley Research Center (LaRC) low aspect ratio research wind tunnel model. To demonstrate the improvements that TACT offers the MSC/PATRAN- and MSC/DIASTRAN- based structural analysis community, a comparison of the modal correlation process using TACT within PATRAN versus external third-party modal correlation packages is presented.
Marlowe, Jill M.↗
Total carbon contents of Apollo 15 and 16 lunar samples
The total carbon contents in Apollo 15 fines range from 29 to 170 micrograms/g. Fines from Apollo 16 range from 65 to 280 micrograms/g. These samples are similar to those from Apollo 11, 12, and 14, with dark colored fines generally containing more carbon than lighter fines. Sample 61221 (light colored fines) is anomalously high with 100 micrograms/g total carbon. Correlations between total carbon content and sample collection station for each mission are evident. Basalts from Apollo 15 have less than 27 micrograms/g total carbon. Anorthositic rocks from Apollo 15 and 16 have less than 20 micrograms/g total carbon. Breccias show complex and variable carbon distributions.
Moore, C. B.↗
Numerical simulation of rarefied flow through a slit. I - Direct simulation Monte Carlo results
The pressure-driven flow of a rarefied monatomic gas through a two-dimensional slit is simulated using the direct simulation Monte Carlo technique. Of particular interest is the change in flow field structure as pressure ratio and Knudsen number are varied. Comparisons are made to quantify the limits of validity of free-molecular theory and approximate, nearly free-molecular iterative methods. Also addressed is the sensitivity of the numerical solutions to grid structure and boundary conditions. The free-molecular theory is found to predict quantitative flow field properties (e.g., centerline velocities or downstream flux profiles) reasonably well for large finite Knudsen number with the error dependent on the pressure ratio. The nearly free-molecular corrections are shown to have limited range of applicability. A previously derived parameter is found to correlate total mass flux well as a function of pressure ratio and Knudsen number over a large portion of the transitional regime.
Wadsworth, D. C.↗
Regional correlation between TOMS total ozone from NIMBUS-7 satellite and geopotential height from the GLAS analysis
In order to study the relation between zone and the atmospheric circulation on a global scale the global correlation has been computed between TOMS total ozone measurements from NIMBUS-7 satellite and collocated geopotential heights analysis at all mandatory pressure levels between 1000-50 mb. The heights are obtained from the 4 deg x 5 deg GLAS analysis that uses both conventional (rawinsonde) and the operational TIROS-N satellite soundings but no ozone data. Zonal averages have been substracted to eliminate the correlation due merely to latitudinal dependence, and emphasize the correlation associated with synoptic features. Tables are presented with correlation coefficients for the four synoptic times covering the Pacific Ocean, Asia, Europe and the Atlantic Ocean, and United States regions. These coverages are approximate since NIMBUS-7 does not observe exactly the same region each day.
Munteanu, M. J.↗
Evaluation of three portable samplers for monitoring airborne fungi
Airborne fungi were monitored at five sample sites with the Burkard portable, the RCS Plus, and the SAS Super 90 air samplers; the Andersen 2-stage impactor was used for comparison. All samplers were calibrated before being used simultaneously to collect 100-liter samples at each site. The Andersen and Burkard samplers retrieved equivalent volumes of airborne fungi; the SAS Super 90 and RCS Plus measurements did not differ from each other but were significantly lower than those obtained with the Andersen or Burkard samplers. Total fungal counts correlated linearly with Cladosporium and Penicillium counts. Alternaria species, although present at all sites, did not correlate with total count or with amounts of any other fungal genera. Sampler and location significantly influenced fungal counts, but no interactions between samplers and locations were found.
NASA Center JSC↗
Total ozone and surface temperature correlations during 1972 - 1981
Ten years of Dobson spectrophotometer total ozone measurements and surface temperature observations were used to construct monthly mean values of the two parameters. The variability of both parameters is greatest in the months of January and February. Indeed, in January there is an apparent correlation between high total ozone values and abnormally low surface temperatures. However, the correlation does not hold in February. By reviewing the history of stratospheric warmings during this period, it is argued that the ozone and surface temperature correlation is influenced by the advection or lack of advection of ozone rich arctic air resulting from sudden stratospheric warmings.
Parsons, C. L.↗
Energy Inputs Uncertainty: Total Amount, Distribution and Correlation Between Different Forms of Energy
Describes solar energy inputs contributing to ionospheric and thermospheric weather processes, including total energy amounts, distributions and the correlation between particle precipitation and Poynting flux.
space weather↗
A 10 micron survey of star formation in galactic nuclei Virgo spiral galaxies
A survey for 10 micron emission in the nuclei of spiral galaxies in the Virgo cluster is reported. It is found that the nuclei of most luminous spiral galaxies are active 10 micron emitters, and that the luminosity function for the sample can be represented by a simple power law over the entire range sampled. The most luminous sources at 10 microns show only a weak correlation with total optical luminosity, and no correlation with morphological type or location in the cluster. It is argued that the 10 micron flux from the Virgo galaxies arises from active star formation regions. A mean far-IR luminosity of two billion solar luminosities is inferred for the galactic nuclei; the required rate of massive star formation is 0.1 solar masses/yr. The results suggest that the rate of star formation in galactic nuclei has little relationship to the size of the nuclear bulge or the gravitational potential near the center.
Becklin, E. E.↗
Characterization of Vertical Ozonesonde Measurements in Equatorial Regions Utilizing the Cooperative Enterprise SHADOZ
Vertical ozone profiles between the Equator and 10 S latitude available from the Southern Hemisphere Additional Ozone (SHADOZ) program provide consistent data Ozone sets from up to 10 sounding locations. SHADOZ designed to provide independent ozone profiles in the tropics for evaluation of satellite ozone data and models has made available over 600 soundings over the period 1998-1999. These observations provide an ideal data base for the detailed description of ozone and afford differential comparison between sites. TOMS total ozone when compared with correlative integrated total ozone overburden from the sondes is found to be negatively biased when using the classical constant mixing ratio procedure to determine residual ozone. On the other hand, the climatological method proposed by McPeters and Labow appears to give consistent results but is positively biased. The longer then two years series of measurements also was subjected to harmonic analysis to examine data cycles. These will be discussed as well.
Schmidlin, F. J.↗
Sulfur abundances and distributions in mare basalts and their source magmas
An inverse correlation between metallic iron content and total sulfur abundances was observed by Gibson and Moore (1974) for five Apollo 17 and six Apollo 15 basalts. An investigation was conducted with the objective to distinguish between two processes leading to the inverse metallic iron and total sulfur correlation. The investigation included analyses of ten Apollo 15 and five Apollo 17 basalts for their sulfur and metallic iron abundances along with carbon and hydrogen. The sulfur isotopic compositions were measured for a possible identification of the fractionation processes which might have occurred during volatilization of the basalts.
Gibson, E. K., Jr.↗