Measurements of the atmospheric concentrations of NO, NO2, total NOy and O3 were made on a 12-m tower in a tundra bog ecosystem in southwestern Alaska during the growing season (July--August) of 1988. Typical concentrations of NOx and NOy were 10--15 pptv, and 130--200 pptv, respectively, lower than at other remote continental sites. Anthropogenic influences were small at this site during this time of year, but significant enhancements in NOx and NOy concentrations were observed from distant biomass fires. Measurements of NOx and O3 vertical profiles, in combination with eddy correlation measurements of O3 flux (Jacob et al., this issue (b), provide an estimate of the NOx emission rate from the surface to the atmosphere, 0.13(¿0.05)¿109 molecules cm-2 s-1. Direct (eddy correlation) measurements of the flux of total Noy were made for the first time, indicating a downward flux of NOy at all times of day, with maximum deposition of 2.5(¿0.9)¿109 molecules cm-2 s-1 in the afternoon. Deposition of HNO3 appears to dominate the atmosphere/surface exchange of NOy. The mean dry deposition rate of NOy to the tundra was 1.8(¿1.0)¿109 molecules cm-2 s-1, about half as large as the wet deposition rate of NO-3 (Talbot et al., this issue). The impact of wet tundra ecosystems on regional and global atmospheric chemistry is discussed in light of these results. ¿ American Geophysical Union 1992