This study reports on the measurements of ion and refractory black carbon (rBC) concentrations in a shallow (10.96 m) ice core sample which was drilled from the field site of the East Greenland Ice Core Project (EGRIP) in July, 2016. The results provide a recent record of rBC deposition in the East Greenland ice sheet from 1990 to 2016. The annual variability in oxygen (delta O-18) and hydrogen (delta D) isotopic compositions indicated that notably warm events occurred since 2008. Peaks in rBC occurred during summer seasons, which may be attributed to the burning of biomass in boreal summer. The rBC record and analysis of historical air trajectories using the HYSPLIT model indicated that anthropogenic BC emissions from Russia, North America and Europe contributed to the majority of rBC deposition in the Greenland region, and a reduction in anthropogenic BC consumption in these areas played a dominant role in the decrease in BC concentrations since 2000. This record also suggests that the emissions from the East Asian region (China) contributed very little to the recorded BC concentrations in East Greenland ice core. The model results indicated that radiative forcing due to BC had decreased significantly since 1990, and had remained below 0.02W m(-2) since 2000.

This study reports on the measurements of ion and refractory black carbon (rBC) concentrations in a shallow (10.96 m) ice core sample which was drilled from the field site of the East Greenland Ice Core Project (EGRIP) in July, 2016. The results provide a recent record of rBC deposition in the East Greenland ice sheet from 1990 to 2016. The annual variability in oxygen (delta O-18) and hydrogen (delta D) isotopic compositions indicated that notably warm events occurred since 2008. Peaks in rBC occurred during summer seasons, which may be attributed to the burning of biomass in boreal summer. The rBC record and analysis of historical air trajectories using the HYSPLIT model indicated that anthropogenic BC emissions from Russia, North America and Europe contributed to the majority of rBC deposition in the Greenland region, and a reduction in anthropogenic BC consumption in these areas played a dominant role in the decrease in BC concentrations since 2000. This record also suggests that the emissions from the East Asian region (China) contributed very little to the recorded BC concentrations in East Greenland ice core. The model results indicated that radiative forcing due to BC had decreased significantly since 1990, and had remained below 0.02W m(-2) since 2000.

Greenland is one of the regions of interest with respect to climate change and global warming in the Northern Hemisphere. Little is known about the structure and diversity of the terrestrial bacterial communities in ice-free areas in northern Greenland. These soils are generally poorly developed and usually carbon- and nitrogen-limited. Our goal was to provide the first insights into the soil bacterial communities from five different sites in Northeast Greenland using culture-independent and culture-dependent methods. The comparison of environmental and biological data showed that the soil bacterial communities are diverse and significantly pH-dependent. The most frequently detected OTUs belonged to the phyla Acidobacteria, Bacteroidetes and (Alpha-, Beta-, Delta-) Proteobacteria. Low pH together with higher nitrogen and carbon concentrations seemed to support the occurrence of (Alpha-, Beta-, Delta-) Proteobacteria (at the expense of Acidobacteria), whereas Bacteroidetes were predominant at higher values of soil pH. Our study indicates that pH is the main factor for shaping bacterial community, but carbon and nitrogen concentrations as well may become important, especially for selecting oligotrophic microorganisms.