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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.

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At least 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Data set for background investigation of atmospheric constituents for Cape Henry site: August 5-22, 1974

The laboratory was located within the Fort Story Military Reservation at Cape Henry between 5 August and 21 August 1974. Total sulfur, total hydrocarbons, NO, NO2, Nox, and O3 were monitored and reported as hourly averages. Visibility was measured using an integrating nephelometer and reported as hourly averages. Twenty-four hour averaged mass loading was determined using two high volume air samplers located on different levels (25' and 50') at the site. Temperature, wind speed, relative humidity, barometric pressure and solar radiation intensity were measured at the site or supplemented by readings taken by the U. S. Coast Guard at the Cape Henry Light House.

Source record↗
NASA NTRS1979

Real-time instrument averages 100 data sets

Instrument generates average curve of 100 consecutive cycles of any function that occurs as time varying electrical signal. Device has been used to average parameters on 1975 Chevrolet V-8 engine, and on Continental six cylinder aircraft engine.

Birchenough, A. G.↗
NASA NTRS1977

Instrument to average 100 data sets

An instrumentation system is currently under development which will measure many of the important parameters associated with the operation of an internal combustion engine. Some of these parameters include mass-fraction burn rate, ignition energy, and the indicated mean effective pressure. One of the characteristics of an internal combustion engine is the cycle-to-cycle variation of these parameters. A curve-averaging instrument has been produced which will generate the average curve, over 100 cycles, of any engine parameter. the average curve is described by 2048 discrete points which are displayed on an oscilloscope screen to facilitate recording and is available in real time. Input can be any parameter which is expressed as a + or - 10-volt signal. Operation of the curve-averaging instrument is defined between 100 and 6000 rpm. Provisions have also been made for averaging as many as four parameters simultaneously, with a subsequent decrease in resolution. This provides the means to correlate and perhaps interrelate the phenomena occurring in an internal combustion engine. This instrument has been used successfully on a 1975 Chevrolet V8 engine, and on a Continental 6-cylinder aircraft engine. While this instrument was designed for use on an internal combustion engine, with some modification it can be used to average any cyclically varying waveform.

Tuma, G. B.↗
NASA NTRS1984

Recorded radiance indices for vegetation monitoring using NOAA AVHRR data; atmospheric and other effects in multitemporal data sets

Work is reported in which a series of cloud-free portions of digital imagery obtained over the Great Plains area of the U.S.A. by the NOAA advanced very high resolution radiometer (AVHRR) throughout the crop growing season were examined in order to study date-dependent and scan-angle-dependent variations in recorded radiance in each sensor channel. Combinations of radiance recorded in different channels (vegetative indices; VINs) were also studied. The problem of atmospheric variation between acquisitions is discussed and some suggestions are made for work which may further improve cloud screening procedures and which may result in vegetation indices which are less affected by atmospheric effects.

Duggin, M. J.↗
NASA NTRS1985

Development of algorithms for using satellite meteorological data sets to study global transport of stratospheric aerosols and ozone

The utilization of stratospheric aerosol and ozone measurements obtained from the NASA developed SAM II and SAGE satellite instruments were investigated for their global scale transports. The stratospheric aerosols showed that during the stratospheric warming of the winter 1978 to 1979, the distribution of the zonal mean aerosol extinction ratio in the northern high latitude exhibited distinct changes. Dynamic processes might have played an important role in maintenance role in maintenance of this zonal mean distribution. As to the stratospheric ozone, large poleward ozone transports are shown to occur in the altitude region from 24 km to 38 km near 55N during this warming. This altitude region is shown to be a transition region of the phase relationship between ozone and temperature waves from an in-phase one above 38 km. It is shown that the ozone solar heating in the upper stratosphere might lead to enhancement of the damping rate of the planetary waves due to infrared radiation alone in agreement with theoretical analyses and an earlier observational study.

Want, P. H.↗
NASA NTRS1987

Nimbus 7 earth radiation budget wide field of view climate data set improvement. II - Deconvolution of earth radiation budget products and consideration of 1982-1983 El Nino event

A deconvolution technique is employed that permits recovery of daily averaged earth radiation budget (ERB) parameters at the top of the atmosphere from a set of the Nimbus 7 ERB wide field of view (WFOV) measurements. Improvements in both the spatial resolution of the resultant fields and in the fidelity of the time averages is obtained. The algorithm is evaluated on a set of months during the period 1980-1983. The albedo, outgoing long-wave radiation, and net radiation parameters are analyzed. The amplitude and phase of the quasi-stationary patterns that appear in the spatially deconvolved fields describe the radiation budget components for 'normal' as well as the El Nino/Southern Oscillation (ENSO) episode years. They delineate the seasonal development of large-scale features inherent in the earth's radiation budget as well as the natural variability of interannual differences. These features are underscored by the powerful emergence of the 1982-1983 ENSO event in the fields displayed. The conclusion is that with this type of resolution enhancement, WFOV radiometers provide a useful tool for the observation of the contemporary climate and its variability.

Ardanuy, Phillip E.↗
NASA NTRS1990

A study of the Baldwin effect in the IUE data set

The paper investigates the controversial relation between the continuum luminosity and the C IV 1550 emission-line strength in the spectra of quasars, commonly referred to as the Baldwin effect, as a possible indicator of absolute luminosity. It is concluded that the Baldwin effect does represent a physical correlation between the continuum and the C IV 1550 equivalent width rather than a consequence of selection effects. In addition to the C IV results, a similar relation is found for the Lyman-alpha emission line.

Kinney, A. L.↗
NASA NTRS1991

Analysis of energy balance models using the ERBE data set

A review of Energy Balance Models is presented. Results from the Outgoing Longwave Radiation parameterization are discussed. The albedo parameterizations and the consequences of the new parameterizations are examined.

Graves, Charles E.↗
NASA NTRS1993

Interactive access and management for four-dimensional environmental data sets using McIDAS

Significant accomplishments in the past year are presented and include the following: (1) enhancements to VIS-5D; (2) Implementation of the VIS AD System; and (3) numerical modeling applications. Focus of current research and plans for next year in the following areas are briefly discussed: (1) continued development and application of the VIS-AD system; (2) further enhancements to VIS-5D; and (3) plans for modeling applications.

Hibbard, William L.↗
NASA NTRS1996

Interpretation of lidar and satellite data sets using a global photochemical model

The status in the beginning of the report period was that the existing General Circulation Model (GCM) was running with a chemistry module compiled for stratospheric simulation studies. The chemistry simulation was not working sufficiently in the troposphere and any tropospheric trace gas sources or dry deposition sinks were not yet incorporated. The current status concerning the chemistry module is that the chemistry simulation has been modified to also simulate the chemistry in the troposphere with resulting mixing ratios close to other model simulations as described in Olson et al. (1996). The mechanism to incorporate trace gas source and dry deposition sinks, testing for H202, CH300H, 03, HCHO, HN03, and N02, are incorporated and is currently being tested. Existing model and development versions include: the full GCM model, currently still running with the original stratospheric chemistry module; an off-line version of the GCM, i.e. wind and photolysis rates are pre-calculated and prescribed in read-in arrays; a box model version of the modified chemistry module for developments and first tests of new modifications; and a box model with the same chemistry simulated but flexible partitioning and integration methods for test purposes of those. The grantee's work focused mainly on three areas: trace gas sources and dry deposition; method to introduce a NO source instead of a NO(x) source; and investigating integration methods.

Chyba, Thomas↗
NASA NTRS1999

Longwave Radiative Flux Calculations in the TOVS Pathfinder Path A Data Set

A radiative transfer model developed to calculate outgoing longwave radiation (OLR) and downwelling longwave, surface flux (DSF) from the Television and Infrared Operational Satellite (TIROS) Operational Vertical Sounder (TOVS) Pathfinder Path A retrieval products is described. The model covers the spectral range of 2 to 2800 cm in 14 medium medium spectral bands. For each band, transmittances are parameterized as a function of temperature, water vapor, and ozone profiles. The form of the band transmittance parameterization is a modified version of the approach we use to model channel transmittances for the High Resolution Infrared Sounder 2 (HIRS2) instrument. We separately derive effective zenith angle for each spectral band such that band-averaged radiance calculated at that angle best approximates directionally integrated radiance for that band. We develop the transmittance parameterization at these band-dependent effective zenith angles to incorporate directional integration of radiances required in the calculations of OLR and DSF. The model calculations of OLR and DSF are accurate and differ by less than 1% from our line-by-line calculations. Also, the model results are within 1% range of other line-by-line calculations provided by the Intercomparison of Radiation Codes in Climate Models (ICRCCM) project for clear-sky and cloudy conditions. The model is currently used to calculate global, multiyear (1985-1998) OLR and DSF from the TOVS Pathfinder Path A Retrievals.

Mehta, Amita↗
NASA NTRS1999

Water Ice Cloud Opacities and Temperatures Derived from the Viking IRTM Data Set

The degree to which water ice clouds play a role in the Mars climate is unknown. Latent heating of water ice clouds is small and since most hazes appeared to be thin (tau less than or = 1) their radiative effects have been neglected. Condensation likely limits the vertical extent of water vapor in the water column and a lowering of the condensation altitude, as seen in the northern spring and summer, could increase the seasonal exchange of water between the atmosphere and the surface. It has been suggested that water ice cloud formation is more frequent and widespread in the aphelic hemisphere (currently the northern). This may limit water to the northern hemisphere through greater exchange with the regolith and through restricted southward transport of water vapor by the Mars Hadley circulation. In addition, it has been suggested that water ice cloud formation also controls the vertical distribution of atmospheric dust in some seasons. This scavenging of dust may Continuing from the IRTM cloud maps, derived cloud opacities and cloud temperatures for several locations and seasons will be presented. Sensitivities to cloud particle sizes, surface temperature, and dust opacity will be discussed.

TamppariL. K.↗