Some missing puzzle pieces in our understanding of the behavior of PAN during a polar spring time ODE
Abstract
During the OASIS campaign, several spring time ozone depletion episodes (ODEs) were observed. The current hypothesis for ODE formation is based on a “Bromine explosion”, which rapidly depletes ozone via the reaction of a Bromine atom with ozone to form BrO and molecular oxygen. This hypothesis was supported by the observation of high concentrations of BrO during the ODEs. A thus far unexplained finding from previous arctic spring time measurements is the lack of variance in PAN concentration during ODEs. The measured mixing ratios of NOx and VOC precursors and the high oxidizing power of halogen atoms would predict either rapid PAN formation or total depletion of NOx. From February 25th to April 15th 2009, a large suite of instruments including the NCAR PAN_CIGARette was deployed at Barrow, Alaska, as part of the OASIS experiment, to gain a better understanding of the gas phase chemistry occurring during an ODE. This paper will present selected preliminary results from the OASIS experiment. An estimation of net PAN accumulation based on current available OASIS data and the comparison between this estimation and the observations will be presented.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.A24B..04Z
- Keywords:
-
- 0317 ATMOSPHERIC COMPOSITION AND STRUCTURE / Chemical kinetic and photochemical properties;
- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional;
- 0365 ATMOSPHERIC COMPOSITION AND STRUCTURE / Troposphere: composition and chemistry