Fig. 8
From: A review of atmospheric chemistry observations at mountain sites
Seasonal variations in NO x and NO y concentrations at six mountain stations. The lines with circles denote the average observed NO x and NO y concentrations during a particular period. The years in parenthesis denote the averaging periods. The red shaded bands and error bars denote the standard deviations. The concentrations of NO x and NO y were measured using photolytic (a–e), thermal Au (f–j), and Mo (k) convertors, followed by chemiluminescence detection