Nitrogen oxide photochemistry in high northern latitudes during spring

• Main Author: Beine, Harald Jurgen
• Other Authors: Jaffe, Daniel A., Benner, Richard, Shaw, Glenn, Stolzberg, Richard, Wendler, Gerd
• Format: Doctoral or Postdoctoral Thesis
• Language: unknown
• Published: 1996
• Subjects: Environmental science; Analytical chemistry; Biogeochemistry; Arctic; Fairbanks; Svalbard; Alaska
• Online Access: http://hdl.handle.net/11122/9415

Dissertation (Ph.D.) University of Alaska Fairbanks, 1996 The transport of NOy reservoir species from midlatitudes into the Arctic and the thermal and photochemical breakup of these species has been proposed to be the most important NOx source during spring, and may have an important influence on the ozone budget. This has not yet been shown to be correct. The objective of this research is to understand the sources of NOx and ozone in high latitudes during spring. To measure NOx, a high sensitivity chemiluminescence NO detector and a photolytic converter for NO$\sb2$ were constructed. The detection limits for NO and NO$\sb2$ were 1.70 and 5.67 part per trillion (pptv) in a one-hour average, respectively. Springtime NOx measurements were carried out concurrently with measurements of ozone, PAN, J(NO$\sb2$), and other species during 1994 at the Zeppelin station on Svalbard, and during 1993 and 1995 at Poker Flat, Alaska. The median mixing ratios of NOx, PAN and ozone at Svalbard were 23.7, 237.0 pptv, and 39.0 parts per billion (ppbv), respectively. During a few ozone depletion events in the Arctic marine boundary layer ozone and NOx mixing ratios were as low as 4 ppbv and 0.9 pptv, respectively. Halogen chemistry is probably responsible for both effects. The median NOx, PAN and ozone mixing ratios at Poker Flat were 79.5 pptv, 85.9 pptv, and 40.6 ppbv, respectively. During April and May diurnal cycles of PAN, ozone and temperature were observed and anticorrelated with the water mixing ratio. We interpret this to be the result of mixing with higher layers of the troposphere during the day. At both locations thermal PAN decomposition was an important NOx source. At Svalbard PAN decomposition was small, and the in-situ ozone production rates are an insignificant contribution to the ozone budget. Because of the higher temperatures, PAN decomposition rates, NOx mixing ratios, and in-situ ozone production rates are higher at Poker Flat. A contribution from this production to the overall ozone budget was visible ...