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Your search keyword '"Wamsley, R. C."' showing total 23 results
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23 results on '"Wamsley, R. C."'

1. Emission Measurements of the Concorde Supersonic Aircraft in the Lower Stratosphere

Author

Fahey, D. W., Keim, E. R., Boering, K. A., Brock, C. A., Wilson, J. C., Jonsson, H. H., Anthony, S., Hanisco, T. F., Wennberg, P. O., Miake-Lye, R. C., Salawitch, R. J., Louisnard, N., Woodbridge, E. L., Gao, R. S., Donnelly, S. G., Wamsley, R. C., Del Negro, L. A., Solomon, S., Daube, B. C., Wofsy, S. C., Webster, C. R., May, R. D., Kelly, K. K., Loewenstein, M., Podolske, J. R., and Chan, K. R.

Published
1995

2. The Role of HOx in Super-and Subsonic Aircraft Exhaust Plumes

Author

Hanisco, T. F, Wennberg, P. O, Cohen, R. C, Anderson, J. G, Fahey, D. W, Keim, E. R, Gao, R. S, Wamsley, R. C, Donnelly, S. G, and DelNegro, L. A

Subjects
Environment Pollution
Abstract

The generation of sulfuric acid aerosols in aircraft exhaust has emerged as a critical issue in determining the impact of supersonic aircraft on stratospheric ozone. It has long been held that the first step in the mechanism of aerosol formation is the oxidation of SO2 emitted from the engine by OH in the exhaust plume. We report in situ measurements of OH and HO2 in the exhaust plumes of a supersonic (Air France Concorde) and a subsonic (NASA ER-2) aircraft in the lower stratosphere. These measurements imply that reactions with OH are responsible for oxidizing only a small fraction of SO2 (2%), and thus cannot explain the large number of particles observed in the exhaust wake of the Concorde.

Published
1997
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3. The role of HO_x in super- and subsonic aircraft exhaust plumes

Author

Hanisco, T. F., Wennberg, P. O., Cohen, R. C., Anderson, J. G., Fahey, D. W., Keim, E. R., Gao, R. S., Wamsley, R. C., Donnelly, S. G., Del Negro, L. A., Salawitch, R. J., Kelly, K. K., and Proffitt, M. H.

Abstract

The generation of sulfuric acid aerosols in aircraft exhaust has emerged as a critical issue in determining the impact of supersonic aircraft on stratospheric ozone. It has long been held that the first step in the mechanism of aerosol formation is the oxidation of SO_(2) emitted from the engine by OH in the exhaust plume. We report in situ measurements of OH and HO_(2) in the exhaust plumes of a supersonic (Air France Concorde) and a subsonic (NASA ER-2) aircraft in the lower stratosphere. These measurements imply that reactions with OH are responsible for oxidizing only a small fraction of SO_(2) (2%), and thus cannot explain the large number of particles observed in the exhaust wake of the Concorde.

Published
1997

4. NO(y) partitioning from measurements of nitrogen and hydrogen radicals in the upper troposphere

Author

Keim, E. R., Keim, E. R., McKeen, S. A., Gao, R. S., Donnelly, S. G., Wamsley, R. C., Del Negro, L. A., Fahey, D. W., Hanisco, T. F., Lanzendorf, E. J., Proffitt, M. H., Margitan, J. J., Hintsa, E. J., Jaeglé, L., Webster, C. R., May, R. D., Scott, D. C., Salawitch, R. J., Wilson, J. C., McElroy, C. T., Atlas, E. L., Flocke, F., Bui, T. P., Keim, E. R., Keim, E. R., McKeen, S. A., Gao, R. S., Donnelly, S. G., Wamsley, R. C., Del Negro, L. A., Fahey, D. W., Hanisco, T. F., Lanzendorf, E. J., Proffitt, M. H., Margitan, J. J., Hintsa, E. J., Jaeglé, L., Webster, C. R., May, R. D., Scott, D. C., Salawitch, R. J., Wilson, J. C., McElroy, C. T., Atlas, E. L., Flocke, F., and Bui, T. P.

Abstract

Recent studies using NO, NO(y), OH and HO2 (HO(X)) observations have postulated acetone and convection of peroxides as significant sources of HO(X) in the upper troposphere (UT). This work focuses on the effect these additional HO(X) sources have on the modeled NO(y) partitioning and comparisons of the modeled NO(x)/NO(y) ratio to observations. The measured NO(x)/NO(y) ratio is usually much higher than predicted regardless of the presence of acetone in the model. The exception occurs for air parcels having low NO(y) and O3 values. For these air parcels the measured NO(x)/NO(y) ratio is much lower than the calculated ratio unless acetone is included in the model. In all cases acetone increases the fraction of NO(y) that is peroxy acetyl nitrate (PAN) from typical values of much less than 0.1 to values as high as 0.35. Including acetone also reduces the scatter in a comparison between modeled and observed NO(x)/NO(y) ratios.

Published
1999

5. Partitioning of the reactive nitrogen reservoir in the lower sratosphere of the southern hemisphere: Observations and modeling

Author

Gao, R. S., Gao, R. S., Fahey, D. W., Salawitch, R. J., Lloyd, S. A., Anderson, D. E., DeMajistre, R., McElroy, C. T., Woodbridge, E. L., Wamsley, R. C., Donnelly, S. G., Del Negro, L. A., Proffitt, M. H., Stimpfle, R. M., Kohn, D. W., Kawa, S. R., Lait, L. R., Loewenstein, M., Podolske, J. R., Keim, E. R., Dye, J. E., Wilson, J. C., Chan, K. R., Gao, R. S., Gao, R. S., Fahey, D. W., Salawitch, R. J., Lloyd, S. A., Anderson, D. E., DeMajistre, R., McElroy, C. T., Woodbridge, E. L., Wamsley, R. C., Donnelly, S. G., Del Negro, L. A., Proffitt, M. H., Stimpfle, R. M., Kohn, D. W., Kawa, S. R., Lait, L. R., Loewenstein, M., Podolske, J. R., Keim, E. R., Dye, J. E., Wilson, J. C., and Chan, K. R.

Abstract

Measurements of nitric oxide (NO), nitrogen dioxide (NO2), and total reactive nitrogen (NOy = NO + NO2 + NO3 + HNO3 + ClONO2 + 2N2O5 + ...) were made during austral fall, winter, and spring 1994 as part of the NASA Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft mission. Comparisons between measured NO2 values and those calculated using a steady state (SS) approximation are presented for flights at mid and high latitudes. The SS results agree with the measurements to within 8%, suggesting that the kinetic rate coefficients and calculated NO2 photolysis rate used in the SS approximation are reasonably accurate for conditions in the lower stratosphere. However, NO2 values observed in the Concorde exhaust plume were significantly less than SS values. Calculated NO2 photolysis rates showed good agreement with values inferred from solar flux measurements, indicating a strong self-consistency in our understanding of UV radiation transmission in the lower stratosphere. Model comparisons using a full diurnal, photochemical steady state model also show good agreement with the NO and NO2 measurements, suggesting that the reactions affecting the partitioning of the NO2 reservoir are well understood in the lower stratosphere.

Published
1997

6. NOy partitioning from measurements of nitrogen and hydrogen radicals in the upper troposphere

Author

Keim, E. R., primary, McKeen, S. A., additional, Gao, R. S., additional, Donnelly, S. G., additional, Wamsley, R. C., additional, Del Negro, L. A., additional, Fahey, D. W., additional, Hanisco, T. F., additional, Lanzendorf, E. J., additional, Proffitt, M. H., additional, Margitan, J. J., additional, Hintsa, E. J., additional, Jaeglé, L., additional, Webster, C. R., additional, May, R. D., additional, Scott, D. C., additional, Salawitch, R. J., additional, Wilson, J. C., additional, McElroy, C. T., additional, Atlas, E. L., additional, Flocke, F., additional, and Bui, T. P., additional

Published
1999
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7. Measurements of the NOy-N2O correlation in the lower stratosphere: Latitudinal and seasonal changes and model comparisons

Author

Keim, E. R., primary, Loewenstein, M., additional, Podolske, J. R., additional, Fahey, D. W., additional, Gao, R. S., additional, Woodbridge, E. L., additional, Wamsley, R. C., additional, Donnelly, S. G., additional, Del Negro, L. A., additional, Nevison, C. D., additional, Solomon, S., additional, Rosenlof, K. H., additional, Scott, C. J., additional, Ko, M. K. W., additional, Weisenstein, D., additional, and Chan, K. R., additional

Published
1997
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8. Evaluating the role of NAT, NAD, and liquid H2SO4/H2O/HNO3 solutions in Antarctic polar stratospheric cloud aerosol: Observations and implications

Author

Del Negro, L. A., primary, Fahey, D. W., additional, Donnelly, S. G., additional, Gao, R. S., additional, Keim, E. R., additional, Wamsley, R. C., additional, Woodbridge, E. L., additional, Dye, J. E., additional, Baumgardner, D., additional, Gandrud, B. W., additional, Wilson, J. C., additional, Jonsson, H. H., additional, Loewenstein, M., additional, Podolske, J. R., additional, Webster, C. R., additional, May, R. D., additional, Worsnop, D. R., additional, Tabazadeh, A., additional, Tolbert, M. A., additional, Kelly, K. K., additional, and Chan, K. R., additional

Published
1997
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10. Partitioning of the reactive nitrogen reservoir in the lower stratosphere of the southern hemisphere: Observations and modeling

Author

Gao, R. S., primary, Fahey, D. W., additional, Salawitch, R. J., additional, Lloyd, S. A., additional, Anderson, D. E., additional, DeMajistre, R., additional, McElroy, C. T., additional, Woodbridge, E. L., additional, Wamsley, R. C., additional, Donnelly, S. G., additional, Del Negro, L. A., additional, Proffitt, M. H., additional, Stimpfle, R. M., additional, Kohn, D. W., additional, Kawa, S. R., additional, Lait, L. R., additional, Loewenstein, M., additional, Podolske, J. R., additional, Keim, E. R., additional, Dye, J. E., additional, Wilson, J. C., additional, and Chan, K. R., additional

Published
1997
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11. In situ observations of NOy, O3, and the NOy/O3 ratio in the lower stratosphere

Author

Fahey, D. W., primary, Donnelly, S. G., additional, Keim, E. R., additional, Gao, R. S., additional, Wamsley, R. C., additional, Del Negro, L. A., additional, Woodbridge, E. L., additional, Proffitt, M. H., additional, Rosenlof, K. H., additional, Ko, M. K. W., additional, Weisenstein, D. K., additional, Scott, C. J., additional, Nevison, C., additional, Solomon, S., additional, and Chan, K. R., additional

Published
1996
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18. Evaluating the role of NAT, NAD, and liquid H2SO4/H2O/HNO3 solutions in Antarctic polar stratospheric cloud aerosol: Observations and implications.

Author

Del Negro, L. A., Fahey, D. W., Donnelly, S. G., Gao, R. S., Keim, E. R., Wamsley, R. C., Woodbridge, E. L., Dye, J. E., Baumgardner, D., Gandrud, B. W., Wilson, J. C., Jonsson, H. H., Loewenstein, M., Podolske, J. R., Webster, C. R., May, R. D., Worsnop, D. R., Tabazadeh, A., Tolbert, M. A., and Kelly, K. K.

Published
1997
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23. Absorption spectroscopy on Hg+ and excited Hg in Hg-Ar discharges.

Author

Wamsley, R. C., Lawler, J. E., Ingold, J. H., Bigio, L., and Roberts, V. D.

Subjects
*LAMPS, *CATHODES, *MERCURY, *ARGON, *ABSORPTION spectra
Abstract

We describe an absorption spectroscopy experiment at 194 nm on Hg+, ground-state atomic mercury ions, and at visible wavelengths on Hg*, excited 63Po mercury atoms in Hg-Ar discharges. This experiment is used to map the absolute density of Hg+ and Hg* in the cathode region of Hg-Ar discharge lamps operated in the hot-cathode mode. [ABSTRACT FROM AUTHOR]

Published
1990
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