Observation of the nighttime nitrate radical in Hefei, China

Abstract

Observation of nighttime nitrate radical (NO 3) was performed by using long path differential optical absorption spectroscopy (LP-DOAS), on the outskirts of Hefei, China. The time series of NO 3 and supporting parameters were simultaneously measured for a week (31 May–7 June 2006). The results indicated that the average concentration of NO 3 was 15.6 pptv with an average lifetimes of 96 s, whereas, NO 3 production rates varied from 8 × 10 5/(cm 3·s) to 2.98 × 10 7/(cm 3·s). Furthermore, the calculated N 2O 5concentration averaged at 380 pptv. Analysis of data indicated that direct sinks were probably dominating the NO 3 loss process during this campaign. The results were compared with other campaigns in the boundary layer.