Relationships between organic nitrates and surface ozone destruction during Polar Sunrise Experiment 1992

Concurrent measurements of total reactive odd nitrogen species (ie NO_y) and its major components, including organic nitrates, were carried out during 1992 Polar Sunrise Experiment (PSE92) at Alert, Northwest Territories, Canada, to investigate the episodic depletion of surface level ozone following polar sunrise. The total concentrations of these organic nitrates ranged from 34 to 128 parts per trillion by volume and the distribution in the dark period was found to be similar to that found for rural lower-latitude air masses. The organic nitrates at Alert were found to contribute between 7 and 20% of the total odd nitrogen species. After polar sunrise the total concentrations of these organic nitrates decreased steadily, due primarily to the consumption of larger (>C₄) alkyl nitrates. The C₃ alkyl nitrate concentrations showed little variation during this study. During ozone depletion episodes in April there was a positive correlation between the concentration of the larger organic nitrates and ozone. -from Authors