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Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
Measurements Of Pernitric Acid At The South Pole During Iscat 2000, D Slusher, L Gregory Huey, D Tanner, G Chen, D D. Davis, Martin Buhr, J Nowak, Fred Eisele, E Kosciuch, R L. Mauldin, Barry Lefer, R E. Shetter, Jack E. Dibb
Measurements Of Pernitric Acid At The South Pole During Iscat 2000, D Slusher, L Gregory Huey, D Tanner, G Chen, D D. Davis, Martin Buhr, J Nowak, Fred Eisele, E Kosciuch, R L. Mauldin, Barry Lefer, R E. Shetter, Jack E. Dibb
Earth Sciences
The first measurements of pernitric acid at the South Pole were performed during the second Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT 2000). Observed HO2NO2 concentrations averaged 25 pptv. Simple steady-state calculations constrained by measurements show that the lifetime of pernitric acid was largely controlled by dry deposition, with thermal decomposition becoming increasingly important at warmer temperatures. We determined that the pernitric acid equilibrium constant is less uncertain than indicated in the literature. One consequence of pernitric acid deposition to the snow surface is that it is an important sink for both NOx and HOx. Another is that …
Studies Of Peroxyacetyl Nitrate (Pan) And Its Interaction With The Snowpack At Summit, Greenland, Kevin M. Ford, Bradley M. Campbell, P B. Shepson, Steven B. Bertman, R E. Honrath, Matthew C. Peterson, Jack E. Dibb
Studies Of Peroxyacetyl Nitrate (Pan) And Its Interaction With The Snowpack At Summit, Greenland, Kevin M. Ford, Bradley M. Campbell, P B. Shepson, Steven B. Bertman, R E. Honrath, Matthew C. Peterson, Jack E. Dibb
Earth Sciences
Peroxyacetyl nitrate (PAN) was measured in ambient and snowpack interstitial air at Summit, Greenland, in June and July of 1998 and 1999 and at a rural/forest site in the Keewenaw Peninsula of Michigan in January of 1999. At Summit, we found that PAN typically represented between 30 and 60% of NOy. In the summer of 1999, a significant diel variation in both PAN/NOy and NOx/NOy was observed, but this was much less pronounced in 1998. Experiments during SNOW99 near Houghton, Michigan, indicated that PAN undergoes weak uptake onto snow grain surfaces. At Summit, we …
Shouldn’T Snowpacks Be Sources Of Monocarboxylic Acids?, Jack E. Dibb, Matthew Arsenault
Shouldn’T Snowpacks Be Sources Of Monocarboxylic Acids?, Jack E. Dibb, Matthew Arsenault
Earth Sciences
We report the first measurements of the mixing ratios of acetic (CH3COOH) and formic (HCOOH) acids in the air filling the pore spaces of the snowpacks (firn air) at Summit, Greenland and South Pole. Both monocarboxylic acids were present at levels well above 1 ppbv throughout the upper 35 cm of the snowpack at Summit. Maximum mixing ratios in Summit firn air reached nearly 8 ppbv CH3COOH and 6 ppbv HCOOH. At South Pole the mixing ratios of these acids in the top 35 cm of firn air were also generally >1 ppbv, though their maximums …
Airborne Sampling Of Aerosol Particles: Comparison Between Surface Sampling At Christmas Island And P-3 Sampling During Pem-Tropics B, Jack E. Dibb, R. Talbot, Garry Seid, C. E. Jordan, Eric Scheuer, Elliot Atlas, Nicola J. Blake, D R. Blake
Airborne Sampling Of Aerosol Particles: Comparison Between Surface Sampling At Christmas Island And P-3 Sampling During Pem-Tropics B, Jack E. Dibb, R. Talbot, Garry Seid, C. E. Jordan, Eric Scheuer, Elliot Atlas, Nicola J. Blake, D R. Blake
Earth Sciences
Bulk aerosol sampling of soluble ionic compounds from the NASA Wallops Island P-3 aircraft and a tower on Christmas Island during PEM-Tropics B provides an opportunity to assess the magnitude of particle losses in the University of New Hampshire airborne bulk aerosol sampling system. We find that most aerosol-associated ions decrease strongly with height above the sea surface, making direct comparisons between mixing ratios at 30 m on the tower and the lowest flight level of the P-3 (150 m) open to interpretation. Theoretical considerations suggest that vertical gradients of sea-salt aerosol particles should show exponential decreases with height. Observed …