Seasonal variations in sulfate, nitrate and chloride in the greenland ice sheet: Relation to atmospheric concentrations

Large-scale spatial trends in recent firn chemistry along an east-west transect through central Greenland

“…Peak timing in our study agrees well with ~other findings from south Greenland (Mayewski et al, 1987;Davidson et al, 1989;Beer et al, 1991) and own findings (unpublished data) from northeast Greenland. Since all these sites cover a wide range of geographical and climatological conditions of the Greenland Ice Sheet, we assume a common temporal deposition pattern for each species over the entire ice sheet.…”

“…Yang et al (1995), however, investigating small temporal changes of annual nitrate firn concentrations in cores from different north hemispherical drill sites, could not confirm such accumulation dependence. Furthermore, Davidson et al (1989) suggest more efficient aerosol scavenging for higher temperatures in the summer months at Dye3, attributed to i enhanced riming of snow flakes during that sea~on.…”

“…• atmospheric concentrations of aerosol species are subject to high variability on a daily and seasonal scale due to their relatively low atmospheric lifetimes; • snow concentrations of mainly wet deposited species are coupled to the atmosphere by single precipitation events; • efficiencies of wet deposition processes are dependent on meteorological parameters such as temperature (Davidson, 1989); and • snow chemistry strata are subject to various postdepositional changes (sublimation, diffusion, wind drift, etc.) (Bales and Wolff, 1995).…”

“…The nitrate summer maximum in snow is not yet satisfactorily explained. Davidson et al (1989) proposed enhanced scavenging of atmospheric nitrate loadings in summer due to higher atmospheric temperatures (higher probability for the occurence of riming). On the other hand, photochemical decomposition during summer of peroxyacetyl nitrate (PAN) (Laj et al, 1992), acting as transient reservoir for reactive nitrogen, or stratospheric inputs in early summer may be responsible for higher atmospheric nitrate concentrations.…”

Source Attribution of Black Carbon in Arctic Snow

“…For example, it is clear that the Russian sites have the highest levels of black carbon and nitrate whereas the sites near the North Pole, interestingly, have the highest non sea salt (NSS) sulfate levels. The Greenland sites, unsurprisingly based on their high altitude and previous studies (e.g., (26)), have the lowest overall concentrations (i.e., the lowest total mass and the lowest mass for most of the individual species analyzed). Positive correlations significant at the 95% level or better were found between black carbon and a number of other species (e.g., nitrate, Al, Fe, acenaphthene).…”