Spatial and Temporal Patterns in Black Carbon Deposition to Dated Fennoscandian Arctic Lake Sediments from 1830 to 2010

Abstract

Black carbon (BC) is fine particulate matter produced by the incomplete combustion of biomass and fossil fuels. It has a strong climate warming effect that is amplified in the Arctic. Long-term trends of BC play an important role in assessing the climatic effects of BC and in model validation. However, few historical BC records exist from high latitudes. We present five lake-sediment soot-BC (SBC) records from the Fennoscandian Arctic and compare them with records of spheroidal carbonaceous fly-ash particles (SCPs), another BC component, for ca. the last 120 years. The records show spatial and temporal variation in SBC fluxes. Two northernmost lakes indicate declining values from 1960 to the present, which is consistent with modeled BC deposition and atmospheric measurements in the area. However, two lakes located closer to the Kola Peninsula (Russia) have recorded increasing SBC fluxes from 1970 to the present, which is likely caused by regional industrial emissions. The increasing trend is in agreement with a Svalbard ice-core-BC record. The results suggest that BC deposition in parts of the European Arctic may have increased over the last few decades, and further studies are needed to clarify the spatial extent of the increasing BC values and to ascertain the climatic implications.

Do contemporary (1980–2015) emissions determine the elemental carbon deposition trend at Holtedahlfonna glacier, Svalbard?

“…A similar rapid increase in BC fluxes between ca. 1970 and 2013 was also observed in two lake sediment records from northern Finland (Ruppel et al, 2015).…”

“…Forsström et al, 2013) and BC deposition (e.g. Ruppel et al, 2013Ruppel et al, , 2015. The modelled BC deposition trend at Holtedahlfonna does not show clear consistency with the observed EC deposition in the ice and firn cores, although some similarities can be observed.…”

“…Moreover, it would be a gross oversimplification to assume that the EC deposition trend at Holtedahlfonna would solely reflect BC emission trends in source areas and/or atmospheric BC concentration trends, since local and regional meteorological processes affect the EC deposition rate notably. As a possible example of the consequences of disregarding temporal meteorological variation, previous modelling results of historical BC deposition in Finland using constant (year 1997) meteorology since 1850 show that the modelled BC deposition trend closely follows the inventory BC emission trend, while the observed BC deposition trend clearly diverged from the modelled trend (Ruppel et al, 2015). One possible explanation for the described discrepancy are variations in meteorological processes affecting BC scavenging efficiencies that were unaccounted for in the model.…”

Impact of forest fires generated black carbon deposition fluxes in Great Hinggan Mountains (China)

“…After the 1980s, BC deposition fluxes in the Great Hinggan Mountains decreased. In contrast, BC deposition fluxes at other worldwide sites (e.g., Tibet Plateau, China; Northern Europe) continued increasing, and the highest deposition fluxes appeared in approximately the 2000s (Cong et al, ; Ruppel et al, ). More intensive human activities in Northeast China, accompanied by accelerated BC production, have led to an increase in BC deposition fluxes in the Sanjiang Plain and Changbai Mountains over the last 150 years, especially after the 1980s (Gao et al, ; Gao et al, ).…”

“…As with regional economic development, high frequency fire events around peatland lead to greater BC deposition into peatland and storage in peat soils. 2013; Ruppel et al, 2015). More intensive human activities in Northeast China, accompanied by accelerated BC production, have led to an increase in BC deposition fluxes in the Sanjiang Plain and Changbai Mountains over the last 150 years, especially after the 1980s (Gao et al, 2016;Gao et al, 2014).…”