Particles are important in the global climate and black carbon (BC) particles are disproportionately important because they absorb sunlight directly warming the atmosphere. Deposition of BC on ice/snow surfaces changes its albedo and enhances melting. The Arctic receives its BC from much of the northern hemisphere. Regional BC emissions have dramatically changed over these 45 years. Therefore, to develop strategies to limit BC and other PM transported to the Arctic, it is essential to determine the regional particulate mass (PM) contributions. The changing climate also affects the production of biogenic sulfate particles that increases the negative radiative forcing.
This collaborative project between Clarkson University and SUNY Albany/ Health Research, Inc/ NYS Health Department with the cooperation of the Finnish Meteorological Institute will develop the world's longest record (45 year time series) of PM compositions of Arctic Haze at a single location by analyzing archived samples collected at Kevo, Finland. This work will: (1) determine the concentrations of BC, SO4 (sulfate), methane sulfonic acid (MSA), and other selected ions, cations and trace elements at Kevo for 45 continuous years; (2) investigate seasonal effects; (3) use state-of-the-art statistical methods, and air parcel back trajectories to determine the contributions of various emission regions and source types to the Arctic region.
This project has the following broader impacts. The resulting long term record of Arctic PM composition variation and its analyses will improve our understanding of Arctic change over nearly a half century. Insights into atmospheric transport and chemical transformation can be gleaned from these data, and identify trends that may extend into the future. The thoroughly analyzed and quality assured data set will be available to the scientific community for comparison of long-term BC and sulfate trends in the Arctic for model evaluations. The other species and data analysis will identify the PM sources over these 45 years. The relative concentrations of absorbing and scattering particles will be determined in this critical geographical area.
This collaboration between Clarkson University, the State University of New York University at Albany, and the Finnish Meteorological Institute in Helsinki Finland has led to the understand of particulate matter observed at Kevo, Finland, near the northern border with Norway. Particles play an important role in global climate in both cooling and warming the earth. Fine particles can travel thousands of kilometers from their sources. Thus, the Arctic receives particles from much of the world. Therefore, to develop strategies to limit further the impacts of particles on the Arctic, it is essential to determine various regional contributions to the observed particulate matter. We have analyzed filters collected weekly from 1964 thru 2010 to investigate the composition and origins of Arctic Haze. The objectives were to: (1) determine the concentrations of black carbon, [BC], SO4=, methane sulfonic acid (MSA), and other anions, cations and trace elements for 47 continuous years; (2) investigate seasonal effects; (3) use statistical methods, and air parcel back trajectories to determine the contributions of various emission regions and source types to the Arctic Haze at Kevo. These data provide the world’s longest record of PM compositions. The results of these studies have been presented in 5 journal papers. MSA and non-sea salt sulfate (NSS-SO4) show clear seasonal trends. MSA peaks from May to July, coinciding with warmer waters and increased biogenic activity in the surrounding seas. NSS-SO4 peaks in March with a minimum during the summer, the typical pattern for Arctic Haze. MSA concentrations were found to be positively correlated with sea surface temperature (SST) anomalies in the surrounding seas (Figure 1). Non sea-salt sulfate (NSS-SO4) declined dramatically in the early 1990s likely from the collapse of the Soviet Union and have continued to decline since the mid-1990s (Figure 2). Species from human activities including V, Co, Cu, Ni, As, Cd, Pb have significantly higher concentrations compared with measurements made at other Arctic locations. A clear seasonal trend with winter/spring maxima and summer minima was observed for most species. High concentrations of Cu (14.1 ng/m3), Ni (0.97 ng/m3), and Co (0.04 ng/m3) indicate the influence of the non-ferrous metal smelters on the Kola Peninsula. The solubility of metals can help determine if the source is natural or anthropogenic. It also dictates the bioavailability of metals once introduced to the environment. Cu, Re, Tl, As, W, and V had high solubility (61%-87%), Co and Ni had solubility’s of ~33%, and Pb had a solubility of 22.9%. Thus, many of these metals come from industrial sources and are readily biologically available. The weekly trace metal and major ion concentrations were analyzed for long-term trends and by source identification methods. Significant long-term decreasing trends were detected for most species. The largest decreases over the 47 years were Sb (-3.90 %/yr), Pb (-3.87 %/yr), Mn (-3.45 %/yr), Cd (-3.42 %/yr), and Ca (-3.13 %/yr). As, Pb, and Cd concentrations at Kevo were consistent with the reported European emissions inventories. Pb concentrations have dramatically decreased (92%) due to the reduced use of leaded gasoline in automobiles. The mean winter, spring, summer, and autumn black carbon [BC] based on the entire data set were 339, 199, 127, and 213 ng m-3, respectively. Annual mean [BC] decreased from ~300 in ~1970 to 82 ng m-3 in 2010 (Figure 4). [BC] at other Arctic sites show similar trends but concentrations at Kevo are generally higher. From ~1970 to 2010 the [BC] decreased by ~1.8% per year. However, [BC] did not decrease monotonically. Instead, cyclical peaks occurred around 1976- 77, 1985-87, and 1999. During such periods, nickel concentrations were well correlated with [BC] suggesting that emissions from the smelting on the Kola Peninsula were significant contributors. The chemical composition dataset was analyzed by Positive Matrix Factorization in multiple ways. The dataset was split in 1979 due to a change from Whatman 42 cellulose filters to a glass fiber filters, and in 1990 due to drops in concentrations related to the economic collapse of the Soviet Union. Two factors representing non-ferrous metal smelters were found for all time periods. One was dominated by Cu and the other by Ni and Co. Each of the time periods contained a factor describing stationary fuel combustion with high percentages of V, BC, and nss-SO4; a ferrous metal factor dominated by Fe and some Mn; a biogenic sulfate factor; a factor containing the majority of Mo and W; and a factor dominated by Sn. Thus, the project has produced an invaluable data set that can be used by others to test models and compare to measurements made at other sites. We have shown the interaction between particle compositions in the Arctic and economic and regulatory driven changes in the source areas and provided additional information on the concentrations of several important particulate species related to climate change.
