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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 325 records · Page 18
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NASA NTRS1982

Carbon monoxide measurements in the troposphere

Approximately 35 hours of radiometric measurements were obtained of the CO mixing ratio in the middle troposphere, upper troposphere, and lower stratosphere, by means of the Measurement of Air Pollution from Satellites (MAPS) experiment carried in the OSTA-1 payload of the second Space Shuttle flight. In view of gas filter radiometer data in the 4.67-micron band, gathered over the 38 N-38 S latitude region during both daytime and nighttime, the performance of MAPS was excellent. Significant gradients have been found in the middle tropospheric CO mixing ratio with both latitude and longitude over the North Atlantic, the Mediterranean Sea, and the Middle East.

Reichle, H. G., Jr.↗
NASA NTRS1983

Correlative nature of ozone and carbon monoxide in the troposphere - Implications for the tropospheric ozone budget

The small-scale vertical variability of troposheric O3 and CO is examined using a set of simultaneous measurements obtained in July and August 1974 between 55 deg S and 67 deg N. From this set of vertical profiles, it is found that many of the fluctuations are coincident in both species, and a method is presented that quantifies the correlation between the observed O3 and CO variability. A two-dimensional depiction of the distribution of these O3-CO correlations reveals that there are regions in the troposphere where these trace gases are positively correlated and that, at the same time, there are preferred locations where these two species are primarily anticorrelated. The regions of anticorrelation are found to be consistent with the traditional picture of the tropospheric ozone cycle, suggesting that this gas is chemically unreactive in the troposphere. On the other hand, the location and magnitude of the region in which these two species are positively correlated indicates that there is considerable in situ production of tropospheric ozone.

Fishman, J.↗
NASA NTRS1983

Variability of carbon monoxide in the Mars atmosphere

Recent measurements and reanalyses of past measurements are used to derive estimates of the variability of CO concentrations in the Martian atmosphere. The J = 1 - 2 rotational transition of CO in the microwave spectrum of Mars was observed in January, 1982, and abundances were calculated through surface and atmospheric temperature modeling. A column density of 4.6 + or - 2.0 x 10 to the 20th/sq cm is obtained, which is contrasted with values of 3.0 + or - 1.0 x 10 to the 20th/sq cm in 1980 and 1.7 x + or - 0.9 x 10 to the 20th/sq cm in 1975 obtained by reanalysis of the J = 0 - 1 transition observed by Good and Schloerb (1981) and Kakar et al. (1977), respectively. It is noted that due to the uncertainties in global atmospheric average temperatures, results are consistent with a CO variability of from 0 to 100 percent over a time scale of several years. It is suggested that simultaneous measurements of the J = 0 - 1 and J = 1 - 2 transitions may provide stronger constraints on the CO abundance and atmospheric temperature of Mars.

Clancy, R. T.↗
NASA NTRS1984

Water loss on Venus - The role of carbon monoxide

The four-to-fivefold difference in water abundance between the earth and Venus may reflect either initial differences in the bulk volatile content of the two planets, or massive water loss mechanisms on Venus. These two possibilities were investigated by performing thermodynamic calculations on the heterogeneous system C-O-H-N-S, varying C/H upward from its 0.033 terrestrial value. While atmospheric H2O decreases as bulk C/H increases, the latter would have to rise to an improbably high value in order to account for the low water abundance on Venus through initial deficiency alone. Calculations suggest that if the outgassed C/H on Venus was higher than on earth by even a factor of 5, it would have been sufficient for CO to become competitive with FeO as a sink for oxygen. Together with the lower initial water abundance value that follows from a higher C/H ratio, water loss due to CO may have been a major factor.

Richardson, S. M.↗
NASA NTRS1984

Gas chromatographic separation of nitrogen, oxygen, argon, and carbon monoxide using custom-made porous polymers from high purity divinylbenzene

Existing porous polymers were surveyed for their ability to separate the subject gases. Certain products that showed more promise than others were synthesized and the existing synthetic procedures studied and modified to produce new polymers with enhanced ability to separate the subject gases. Evaluation of the porous polymers was carried out practically by gas chromatography at ambient temperature. The modified synthetic procedures were somewhat simpler than the originals. The new porous polymers made with high purity divinylbenzene enabled use of shorter columns to obtain the separations desired.

Pollock, G. E.↗
NASA NTRS1985

Carbon monoxide isotope ratios in galactic centers and disks

For each of the six galaxies whose mm-wavelength emission of CO and C-13O were observed from both the center and the disk, and the ratio of integrated intensities P(CO)/P(C-13O) is noted to vary markedly from galactic center to galactic center, from galactic disk to galactic disk, and from point to point within a given galaxy. The observed integrated intensity ratios vary from 3 to 16, indicating that the use of a constant P(CO) to sigma(H2) conversion to derive H2 surface densities from extragalactic CO observations can produce major errors.

Rickard, L. J.↗
NASA NTRS1985

More extragalactic carbon monoxide

CO emission has been detected toward the centers of six spiral galaxies - NGC 660, 3504, 3628, 4303, 4631, and 4826 - which had been predicted to have molecular sources similar to that in the center of the Galaxy on the basis of OH and IR studies. Analysis of the entire sample of galaxies with strong central CO peaks supports the interpretation of the central peaks as components distinct from the disk molecular clouds. A new method for estimating the mass of associated H2 is suggested that emphasizes the different kinds of clouds in these different regions. There appears to be no correlation of CO and H I linewidths. However, there are good correlations between CO emission, far-infrared emission, and nonthermal radio continuum emission. The correlation with infrared emissions shows that more molecular gas implies more star formation in galactic centers.

Rickard, L. J.↗
NASA NTRS1985

Operational overview of Wallops Island instrument intercomparison - Carbon monoxide, nitric oxide, and hydroxyl instrumentation

NASA has initiated the Global Tropospheric Experiment (GTE) for the study of the chemistry of the global troposphere. One phase of GTE, Chemical Instrumentation Test and Evaluation (CITE), is concerned with the development and validation of measurement techniques for trace species which play important roles in the tropospheric chemical cycles. In connection with CITE 1 an intercomparison of instruments is conducted for the measurement of CO, NO, and OH. These species have been identified as critical for an understanding of homogeneous gas-phase chemistry in the troposphere. The present paper provides an operational overview of the first of three instrument intercomparison field missions conducted as part of GTE/CITE 1. The missions include one ground-based and two airborne missions, and were designed to characterize current capability of measuring ambient levels of CO, NO, and OH.

Gregory, G. L.↗
NASA NTRS1986

Fourier transform spectrometer observations of solar carbon monoxide. II - Simultaneous cospatial measurements of the fundamental and first-overtone bands, and Ca II K, in quiet and active regions

Fourier transform spectrometry has yielded simultaneous cospatial measurements of important diagnostics of thermal structure in the high solar photosphere and low chromosphere. It is noted that the anomalous behavior of the fundamental bands of CO in quiet areas near the limb is accentuated in an active region plage observed close to the limb. The difference between the core temperatures of the CO fundamental bands in a plage and a nearby quiet region at the limb is larger than the corresponding brightness temperature differences in the inner wings of the Ca II line measured in a quiet region and several plages closer to the disk center. Numerical simulations indicate that the disparate behavior of the CO bands with respect to Ca II K cannot be reconciled with existing single component thermal structure models; a two-component atmosphere is required.

Ayres, T. R.↗
NASA NTRS1986

Methane, carbon monoxide and methylchloroform in the Southern Hemisphere

New observational data on CH4, CO and CH3CCl3 in the Southern Hemisphere are reported. The data are analyzed for long term trends and seasonal cycles. CH3CCl3 data are used to scale the OH fields incorporated in a two-dimensional model, which in turn, is used to constrain the magnitude of a global CH4 source function. The possible causes of observed seasonality of CH3CCl3, CH4 and CO are identified, and several other aspects of observed CH4 variability are discussed. Possible future research directions are also given.

Fraser, P. J.↗
NASA NTRS1986

Carbon monoxide production in low energy oxygen ion bombardment of pyrolytic graphite and Kapton surfaces

The results of an investigtion of the interaction of low energy oxygen ions with pyrolytic graphite and Kapton surface are reported. CO molecules emitted from the surface as a result of the ion bombardment were detected by a mass spectrometer. Because the ion-induced signals were small compared to that arising from the CO background pressure in the vacuum system, the ion beam was modulated and the modulated component of the CO signal measured with a lock-in amplifier. The quantum yield (CO molecules emitted per incident oxygen ion) for graphite rose from 1.9 at 4.5 eV ion energy to 6.6 at 465 eV. Comparable yields were obtained for Kapton. The large size of the yields suggests contributions to the reaction process from the background O2 molecules in the vacuum system.

Horton, C. C.↗
NASA NTRS1987

Field test to intercompare carbon monoxide, nitric oxide and hydroxyl instrumentation at Wallops Island, Virginia

Documentation of the first of three instrument intercomparisons conducted as part of NASA Global Tropospheric Experiment/Chemical Instrumentation Test and Evaluation (GTE/CITE-1) is given. This ground-based intercomparison was conducted during July 1983 at NASA Wallops Flight Facility. Instruments intercompared included one laser system and three grab-sample approaches for CO; two chemiluminescent systems and one laser-induced fluorescent (LIF) technique for NO; and two different LIF systems and a radiochemical tracer technique for OH. The major objectives of this intercomparison was to intercompare ambient measurements of CO, NO, and OH at a common site by using techniques of fundamentally different detection principles and to identify any major biases among the techniques prior to intercomparison on an aircraft platform. Included in the report are comprehensive discussions of workshop requirements, philosophies, and operations as well as intercomparison analyses and results. In addition, the large body of nonintercomparison data incorporated into the workshop measurements is summarized. The report is an important source document for those interested in conducting similar large and complex intercomparison tests as well as those interested in using the data base for purposes other than instrument intercomparison.

Gregory, Gerald L.↗
NASA NTRS1987

Carbon monoxide emission from small galaxies

A search was conducted for J = 1 yields 0 CO emission from 22 galaxies, detecting half, as part of a survey to study star formation in small to medium size galaxies. Although substantial variation was found in the star formation efficiencies of the sample galaxies, there is no apparent systematic trend with galaxy size.

Thronson, Harley A., Jr.↗
NASA NTRS1986

Synthesis of a further improved porous polymer for the separation of nitrogen, oxygen, argon, and carbon monoxide by gas chromatography

A further improvement has been made in the synthesis of an N-type porous polymer for the separation of permanent gases. Changing the ratios of reactants and diluting the Hi-DVB with styrene led to a porous polymer gas chromatographic packing which is superior to commercial products and to the author's own previously reported custom-made polymer.

Pollock, G. E.↗
NASA NTRS1986

Analysis of remote measurements of tropospheric carbon monoxide concentrations made during the 1979 Summer Monsoon Experiment (MONEX)

Mixing ratios of tropospheric CO as measured by an aircraft-mounted radiometer over Saudi Arabia, the Arabian Sea, and northern India during May and June 1979 are reported. During early May, exceptionally high CO levels were detected over Saudi Arabia, and strong horizontal gradients in CO mixing ratios were seen to develop over a period of several days. Over the Arabian Sea, mixing ratios of the order of 150 parts per billion by volume were observed before the monsoon onset, and a pronounced decrease in CO was detected toward the equator. Subsequent measurements after the monsoon had become established revealed a consistent decrease in CO mixing ratio across this region. Analysis of aircraft dropsonde data and constant pressure daily streamline charts lend strong support to the hypothesis that this reduction is associated with the influx of CO-poor Southern Hemisphere air in the monsoon southwesterlies.

Doherty, G. M.↗
NASA NTRS1986

Aperture-synthesis observations of carbon monoxide in the Egg Nebula

Observations of the 2.6-mm CO emission of the bipolar nebular CRL 2688, obtained with resolution 7 arcsec using the mm-wave interferometer at Owens Valley during December 1982-June 1983, are reported. The emission of a 10 x 15-arcsec core, centered on the optical reflection nebula and probably surrounded by a large cloud of cooler gas, is found to have a main-axis velocity gradient of 3 km/s arcsec and an excitation temperature of about 70 K.

Heiligman, G. M.↗
NASA NTRS1986

Detection of carbon monoxide in Saturn

The detection of CO in the atmosphere of Saturn is reported. Six spectral regions containing lines of the CO 1-0 vibration-rotation band near 4.7 microns are studied; three of the lines are free of blending and in effect attest to the presence of this molecule in Saturn's atmosphere. Consideration is given to the following CO sources: (1) rapid convection from the hot interior, and (2) the infall of oxygen-bearing material from outside.

Noll, Keith S.↗