Zobrazeno 1 - 10
of 29
pro vyhledávání: '"E. R. Keim"'
Autor:
Ru-Shan Gao, S. G. Donnelly, J.-F. Blavier, A. Y. Chang, G. C. Toon, Ross J. Salawitch, T. P. Bui, E. R. Keim, G. B. Osterman, Robert L. Herman, Markus Rex, David W. Fahey, M. R. Gunson, Bhaswar Sen, J. A. Neuman, D. C. Scott, Fredrick W. Irion, R. D. May, Elisabeth J. Moyer, James J. Margitan, Curtis P. Rinsland, Christopher R. Webster
Publikováno v:
Journal of Geophysical Research: Atmospheres. 104:26611-26623
We use the correlation between CH(sub 4) and N(sub 2)O as measured during the POLARIS campaign in spring 1997 to estimate the degree of mixing between descended air masses from the vortex and air masses from mid-latitudes.
Autor:
Sean C. Solomon, David W. Fahey, E. R. Keim, Max Loewenstein, J. R. Podolske, James W. Elkins, Cynthia D. Nevison
Publikováno v:
Global Biogeochemical Cycles. 13:737-742
Recent isotopic studies have suggested that the trace gas N 2 O has a missing stratospheric sink of potentially major significance. While these studies have raised interesting questions, the constraints on N 2 O photochemistry imposed by correlations
Autor:
Eric J. Hintsa, E. R. Keim, James C. Wilson, Elliot Atlas, R. S. Gao, Michael H. Proffitt, J. J. Margitan, S. G. Donnelly, Thomas F. Hanisco, Frank Flocke, L. A. Del Negro, Ross J. Salawitch, C. T. McElroy, D. C. Scott, R. C. Wamsley, T. P. Bui, C. R. Webster, E. J. Lanzendorf, Lyatt Jaeglé, R. D. May, Stuart A. McKeen, David W. Fahey
Publikováno v:
Geophysical Research Letters. 26:51-54
Recent studies using NO, NOy, OH and HO2 (HOx) observations have postulated acetone and convection of peroxides as significant sources of HOx in the upper troposphere (UT). This work focuses on the effect these additional HOx sources have on the mode
Publikováno v:
Geophysical Research Letters. 25:3323-3326
In situ measurements in the engine exhaust of a Concorde supersonic aircraft in the lower stratosphere are used to constrain heterogeneous reaction rates on soot particles in a plume model. Upper limit values are obtained for the product of the react
Autor:
Christopher R. Webster, Bruce E. Anderson, Sue M. Schauffler, Max Loewenstein, S. W. Bowen, P. R. Wamsley, K. A. Boering, K. R. Chan, T. P. Bui, Andrew J. Weinheimer, S. Donnelly, Frank Flocke, G. W. Sachse, James W. Elkins, James J. Margitan, Denise D. Montzka, E. R. Keim, James R. Podolske, Mark R. Schoeberl, Teresa Campos, L. A. Del Negro, Paul A. Newman, Leslie R. Lait, R. D. May, Michael H. Proffitt, Stephanie A. Vay, Brian A. Ridley, S. C. Wofsy, James Walega, Arlyn E. Andrews, J. E. Collins, Bruce C. Daube, Elliot Atlas
Publikováno v:
Journal of Geophysical Research: Atmospheres. 103:22087-22096
We compare measurements of six species taken aboard NASA DC-8 and ER-2 aircraft during two flight legs in the tropical middle troposphere near Hawaii. NO, NOy, O3, CH4, and N2O measurements agree to within the limits set by the known systematic error
Autor:
David W. Fahey, Robert L. Herman, E. J. Lanzendorf, E. R. Keim, Paul O. Wennberg, Thomas F. Hanisco, Elliot Atlas, Ruixuan Gao, C. T. McElroy, L. A. Del Negro, Ross J. Salawitch, Eric J. Hintsa, M. H. Proffitt, J. J. Margitan, D. J. Jacob, S. G. Donnelly, S. A. McKeen, Frank Flocke, C. R. Webster, R. D. May, Lyatt Jaeglé, T. P. Bui, James G. Anderson, S. M. Schauffler
Publikováno v:
Science. 279:49-53
The concentrations of the hydrogen radicals OH and HO 2 in the middle and upper troposphere were measured simultaneously with those of NO, O 3 , CO, H 2 O, CH 4 , non-methane hydrocarbons, and with the ultraviolet and visible radiation field. The dat
Autor:
David W. Fahey, Leonhard Pfister, Clive Midwinter, Thomas F. Hanisco, Paul O. Wennberg, Frank Flocke, C. M. Spivakovsky, Eric J. Hintsa, James C. Wilson, C. T. McElroy, D. J. Jacob, Elliot Atlas, Michael H. Proffitt, Sue M. Schauffler, Lyatt Jaeglé, E. R. Keim, E. J. Lanzendorf
Publikováno v:
Geophysical Research Letters. 24:3181-3184
ER-2 aircraft observations of OH and HO_2 concentrations in the upper troposphere during the NASA/STRAT campaign are interpreted using a photochemical model constrained by local observations of O_3, H_2O, NO, CO, hydrocarbons, albedo and overhead ozo
Autor:
Tomasz Gierczak, Thomas F. Hanisco, Stuart A. McKeen, David W. Fahey, Paul O. Wennberg, A. R. Ravishankara, E. R. Keim, Shaw Chen Liu, James B. Burkholder, R. S. Gao
Publikováno v:
Geophysical Research Letters. 24:3177-3180
This paper summarizes measured photodissociation quantum yields for acetone in the 290-320 nm wavelength region for pressures and temperatures characteristic of the upper troposphere. Calculations combine this laboratory data with trace gas concentra
Autor:
Douglas R. Worsnop, Ru-Shan Gao, James C. Wilson, David W. Fahey, J. R. Podolske, Christopher R. Webster, K. R. Chan, Max Loewenstein, Margaret A. Tolbert, E. L. Woodbridge, Darrel Baumgardner, L. A. Del Negro, R. C. Wamsley, Azadeh Tabazadeh, B. W. Gandrud, R. D. May, Haflidi Jonsson, K. K. Kelly, E. R. Keim, S. G. Donnelly, James E. Dye
Publikováno v:
Journal of Geophysical Research: Atmospheres. 102:13255-13282
Airborne measurements of total reactive nitrogen (NOy) and polar stratospheric cloud (PSC) aerosol particles were made in the Antarctic (68°S) as part of the NASA Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects o
Autor:
J. R. Podolske, David W. Fahey, Max Loewenstein, James W. Elkins, S. C. Wofsy, L. R. Lait, Paul A. Newman, M. H. Proffitt, K. K. Kelly, Geoff S. Dutton, Darryn W. Waugh, E. R. Keim, Bruce C. Daube, C. M. Volk, K. R. Chan, Ru-Shan Gao, Kristie A. Boering, R. A. Plumb
Publikováno v:
Journal of Geophysical Research: Atmospheres. 102:13119-13134
The occurrence of mixing of polar vortex air with midlatitude air is investigated by examining the scatterplots of insitu measurements of long-lived tracers from the NASA ER-2 aircraft during the Stratospheric Photochemistry, Aerosols and Dynamics Ex