A 60 Year Record of Atmospheric Aerosol Depositions Preserved in a High‐Accumulation Dome Ice Core, Southeast Greenland

Abstract

The Southeastern Greenland Dome (SE‐Dome) has both a high elevation and a high accumulation rate (1.01 m we yr−1), which are suitable properties for reconstructing past environmental changes with a high time resolution. For this study, we measured the major ion fluxes in a 90 m ice core drilled from the SE‐Dome region in 2015 and present the records of annual ion fluxes from 1957 to 2014. From 1970 to 2010, the trend of nonsea‐salt (nss) SO42− flux decreases, whereas that for NH4+ increases, tracking well with the anthropogenic SOx and NH3 emissions mainly from North America. The result suggests that these fluxes reflect histories of the anthropogenic SOx and NH3 emissions. In contrast, the decadal trend of NO3− flux differs from the decreasing trend of anthropogenic NOx emissions. Although the cause of this discrepancy remains unclear, it may be related to changes in particle formation processes and chemical scavenging rates caused by an increase in sea salt and dust and/or a decrease in nssSO42−. We also find a high average NO3− flux (1.13 mmol m−2 yr−1) in the ice core, which suggests a negligible effect from postdepositional NO3− loss. Thus, the SE‐Dome region is an excellent location for reconstructing nitrate fluxes. Over a decadal time scale, our NO3− flux record is similar to those from other ice cores in Greenland high‐elevation sites, suggesting that NO3− concentration records from these ice cores are reliable.

A Factor and Trends Analysis of Multidecadal Lower Tropospheric Observations of Arctic Aerosol Composition, Black Carbon, Ozone, and Mercury at Alert, Canada

“…Considering that Eurasian emissions showed a relative increase in NH 3 to SO x (Figure c), the associated reduction in aerosol acidity at Alert (Figure d) likely shifted the partitioning of atmospheric nitrate from gaseous nitric acid to aerosol nitrate (e.g., Guo et al, ). Similar trends in nitrate were also found in Greenland ice cores (Iizuka et al, ).…”

Isotopic evidence for acidity-driven enhancement of sulfate formation after SO 2 emission control

“…The ion fluxes of the species used in Fig. 1 are from a previous study (38). To match the resolution of ion fluxes and  17 O SO 4…”

“…The record from the past 60 years covers the high-pollution decades of the 1950s to 1970s as well as the substantial SO 2 emissions-reduction period from the 1980s to the present (1). The SE-Dome ice core preserves atmospheric aerosols that originate mainly from NA and WE, with no notable change in the air mass origin over the period (38). We reconstructed  17 O SO 4 2− in 3 to 6 years resolution with an accuracy of dating better than 2 months, which is given by precise age-depth scaling with the oxygen-isotope matching method (39). )…”

Variations in mineralogy of dust in an ice core obtained from northwestern Greenland over the past 100 years

“…According to previous studies, some minerals have localized distributions. Ito and Wagai (2017) showed the global terrestrial distribution of clay size mineral groups, revealing that Type A minerals were predominant in humid regions in low-or middle-latitude areas, whereas Type B minerals were abundant in arid and/or highlatitude areas. Furthermore, kaolinite (Type A) can be used as an indicator of intensive weathering in palaeoclimatic conditions (Biscaye, 1965;Griffin et al, 1968).…”