first_imgDetailed chemical analysis of the 122 m, relatively high-altitude and lowmelt Lomonosovfonna ice core provides the best-dated record of nitrate from Svalbard. A very significant non-linear trend present in the record shows: (a) a rise in concentrations from the 12th to the mid-16th century, (b) reasonably stable concentrations until the mid19th century, (c) a rise in concentrations into the 20th century, with (d) a rapid rise in the 1950s and (e) a decrease after the mid-1980s. Nitrate is well correlated with ammonium before 1920 and after 1960 but not in the intervening period. The correlation between ammonium and nitrate concentrations indicates that ammonium nitrate (NH4NO3) has been common at Lomonosovfonna. There are also places in the core where nitrate is very closely associated with calcium.last_img read more