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Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Photochemical Production Of Gas Phase No X From Ice Crystal No3 −, R E. Honrath, S Guo, Matthew C. Peterson, M P. Dziobak, Jack E. Dibb, Matthew Arsenault
Photochemical Production Of Gas Phase No X From Ice Crystal No3 −, R E. Honrath, S Guo, Matthew C. Peterson, M P. Dziobak, Jack E. Dibb, Matthew Arsenault
Earth Sciences
Recent measurements have demonstrated that sunlight irradiation of snow results in the release of significant amounts of gas phase NOx (NO+NO2). We report here the results of a series of experiments designed to test the hypothesis that the observed NOx production is the result of nitrate photolysis. Snow produced from deionized water with and without the addition of nitrate was exposed to natural sunlight in an outdoor flow chamber. While NOx release from snow produced without added NO−3 was minimal, the addition of 100 µM NO−3resulted in the release …
Release Of No(X) From Sunlight-Irradiated Midlatitude Snow, R E. Honrath, Matthew C. Peterson, M P. Dziobak, Jack E. Dibb, Matthew Arsenault, S A. Green
Release Of No(X) From Sunlight-Irradiated Midlatitude Snow, R E. Honrath, Matthew C. Peterson, M P. Dziobak, Jack E. Dibb, Matthew Arsenault, S A. Green
Earth Sciences
Photochemical production and release of gas-phase NO(x) (NO + NO2) from the natural snowpack at a remote site in northern Michigan were investigated during the Snow Nitrogen and Oxidants in Winter study in January 1999. Snow was collected in an open 34 L chamber, which was then sealed with a transparent Teflon cover and used as an outdoor flow and reaction chamber. Significant increases in NO(x) mixing ratio were observed in synthetic and ambient air pulled through the sunlit chamber. [NO(x)] enhancements were correlated to ultraviolet sunlight intensity, reaching ~300 pptv under partially overcast midday, mid-winter conditions. These findings are …
Tropospheric Reactive Odd Nitrogen Over The South Pacific In Austral Springtime, Jack E. Dibb, R. Talbot, Eric Scheuer, J D. Bradshaw, S T. Sandholm, D R. Blake, N J. Blake, Elliot Atlas, F Flocke
Tropospheric Reactive Odd Nitrogen Over The South Pacific In Austral Springtime, Jack E. Dibb, R. Talbot, Eric Scheuer, J D. Bradshaw, S T. Sandholm, D R. Blake, N J. Blake, Elliot Atlas, F Flocke
Earth Sciences
The distribution of reactive nitrogen species over the South Pacific during austral springtime appears to be dominated by biomass burning emissions and possibly lightning and stratospheric inputs. The absence of robust correlations of reactive nitrogen species with source-specific tracers (e.g., C2H2 [combustion], CH3Cl [biomass burning], C2Cl4 [industrial],210Pb [continental], and 7Be [stratospheric]) suggests significant aging and processing of the sampled air parcels due to losses by surface deposition, OH attack, and dilution processes. Classification of the air parcels based on CO enhancements indicates that the greatest influence was found in …
Chemical Nox Budget In The Upper Troposphere Over The Tropical South Pacific, Martin G. Schultz, Daniel J. Jacob, J D. Bradshaw, S T. Sandholm, Jack E. Dibb, R. Talbot, Hanwant B. Singh
Chemical Nox Budget In The Upper Troposphere Over The Tropical South Pacific, Martin G. Schultz, Daniel J. Jacob, J D. Bradshaw, S T. Sandholm, Jack E. Dibb, R. Talbot, Hanwant B. Singh
Earth Sciences
The chemical NOx budget in the upper troposphere over the tropical South Pacific is analyzed using aircraft measurements made at 6-12 km altitude in September 1996 during the Global Tropospheric Experiment (GTE) Pacific Exploratory Mission (PEM) Tropics A campaign. Chemical loss and production rates of NOx along the aircraft flight tracks are calculated with a photochemical model constrained by observations. Calculations using a standard chemical mechanism show a large missing source for NOx; chemical loss exceeds chemical production by a factor of 2.4 on average. Similar or greater NOx budget imbalances have been reported in analyses of data from previous …
Composition And Distribution Of Aerosols Over The North Atlantic During The Subsonic Assessment Ozone And Nitrogen Oxide Experiment (Sonex), Jack E. Dibb, R. Talbot, Eric Scheuer
Composition And Distribution Of Aerosols Over The North Atlantic During The Subsonic Assessment Ozone And Nitrogen Oxide Experiment (Sonex), Jack E. Dibb, R. Talbot, Eric Scheuer
Earth Sciences
We report the mixing ratios of aerosol-associated soluble ions (focusing on SO4= and NO3−) and HNO3 over the North Atlantic during NASA's Subsonic Assessment Ozone and Nitrogen Oxide Experiment (SONEX). The SONEX campaign was designed to quantify the impacts of jet emissions in the North Atlantic Flight Corridor (NAFC) by sampling both directly within and far removed from the organized track system. Beryllium-7 activities were also measured to assess the magnitude of stratospheric influence in the SONEX study region. Mixing ratios of aerosol-associated SO4= and NO3− above 8 km during …