The individual depth profiles of benzene and toluene showed less identifiable patterns than those in the Southern Ocean (Figure and). Hence, we use depth bin averaging to make the trends visually clearer (Figure ). Within the 75 to 90 % SIC bin (near-full sea ice cover), benzene and toluene concentrations gradually decreased from the surface to 20-30 m. At partial sea ice cover (20-50 % SIC), benzene and toluene were mixed more homogenously within the 40 m near the surface. In ice-free conditions (0 % SIC), subsurface peaks in benzene and toluene occurred which were often situated around a subsurface peak in Chl a concentration. In the Arctic, a substantial amount of biological activity occurs below the surface at this Chl a peak . Thus, subsurface peaks of benzene and toluene co-located with Chl a support a biological source. Other biogenic gases, such as DMS and isoprene also displayed higher concentrations at the depth of peak Chl a concentration compared to 5 m below the surface . About 20 % of the stations displayed higher concentrations at 30 cm than at 2 m. The concentration increase often coincided with lower seawater density (Figure and S6) and suggests fine scale vertical variability in the processes controlling concentrations of benzene and toluene, similar to other biogenic gases during this cruise . Overall, these measurements support distinct biological sources for benzene and toluene in the Arctic Ocean related to Chl a, though the precise factors controlling their distribution are far from clear.