scholarly journals Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions

2019 ◽  
Vol 19 (10) ◽  
pp. 6913-6929 ◽  
Author(s):  
Christopher Pearson ◽  
Dean Howard ◽  
Christopher Moore ◽  
Daniel Obrist
Keyword(s):  
Trace Metal ◽  
Wet Deposition ◽  
The United States ◽  
Environmental Conservation ◽  
The Arctic ◽  
Lower Latitude ◽  
Back Trajectory ◽  
Source Regions ◽  
Kodiak Island ◽  
Precipitation Regimes

Abstract. A total of 1360 weeks of mercury (Hg) wet deposition data were collected by the state of Alaska Department of Environmental Conservation and the U.S. National Park Service across five stations spanning up to 8 years. Here, we analyze concentration patterns, source regions, and seasonal and annual Hg deposition loadings across these five sites in Alaska, along with auxiliary trace metals including Cr, Ni, As, and Pb. We found that Hg concentrations in precipitation at the two northernmost stations, Nome (64.5∘ N) along the coast of the Bering Sea and the inland site of Gates of the Arctic (66.9∘ N), were statistically higher (average of 5.3 and 5.5 ng L−1, respectively) than those at the two lowest-latitude sites, Kodiak Island (57.7∘ N, 2.7 ng L−1) and Glacier Bay (58.5∘ N, 2.6 ng L−1). These differences were largely explained by different precipitation regimes, with higher precipitation at the lower-latitude stations leading to dilution effects. The highest annual Hg deposition loads were consistently observed at Kodiak Island (4.80±1.04 µg m−2), while the lowest annual deposition was at Gates of the Arctic (2.11±0.67 µg m−2). Across all stations and collection years, annual precipitation strongly controlled annual Hg deposition, explaining 73 % of the variability in observed annual Hg deposition. The data further showed that annual Hg deposition loads across all five Alaska sites were consistently among the lowest in the United States, ranking in the lowest 1 % to 5 % of over 99 monitoring stations. Detailed back-trajectory analyses showed diffuse source regions for most Hg deposition sites suggesting largely global or regional Hg sources. One notable exception was Nome, where we found increased Hg contributions from the western Pacific Ocean downwind of East Asia. Analysis of other trace elements (As, Cr, Cu, Ni, Pb, Se, Zn) from Dutch Harbor, Nome, and Kodiak Island showed generally higher trace metal concentrations at the northern station Nome compared to Kodiak Island further to the south, with concentrations at Dutch Harbor falling in between. Across all sites, we find two distinct groups of correlating elements: Cr and Ni and As and Pb. We attribute these associations to possibly different source origins, whereby sources of Ni and Cr may be derived from crustal (e.g., dust) sources while As and Pb may include long-range transport of anthropogenic pollution. Hg was not strongly associated with either of these two groups.

scholarly journals Mercury and trace metal wet deposition across five stations in Alaska: controlling factors, spatial patterns, and source regions

2018 ◽  
Author(s):  
Christopher Pearson ◽  
Dean Howard ◽  
Christopher Moore ◽  
Daniel Obrist
Keyword(s):  
Trace Elements ◽  
Trace Metal ◽  
Wet Deposition ◽  
Enrichment Factors ◽  
The Arctic ◽  
Lower Latitude ◽  
Diffuse Source ◽  
Source Regions ◽  
Kodiak Island ◽  
Annual Deposition

Abstract. A total of 1,360 weeks of mercury (Hg) wet deposition data were collected by the State of Alaska Department of Environmental Conservation and the U.S. National Park Service, across five stations covering up to eight years. Here, we analyze concentration patterns, source regions, and seasonal and annual deposition loadings across these five sites in Alaska, along with auxiliary trace metals including Cr, Ni, As, and Pb. We found that Hg concentrations in precipitation at the two northern-most stations, Nome (64.5° N) along the coast of the Bering Sea and the inland site of Gates of the Arctic (66.9° N), were significantly higher (average of 5.3 ng L−1 and 5.5 ng L−1, respectively) than those at the two lowest-latitude sites, Kodiak Island (57.7° N, 2.7 ng L−1) and Glacier Bay (58.5° N, 2.6 ng L−1). These differences were largely explained by different precipitation regimes, with higher amounts of precipitation at the lower latitude stations leading to dilution effects. Highest annual Hg deposition loads were consistently observed at Kodiak Island (4.80 +/− 1.04 µg m−2), while lowest annual deposition was at Gates of the Arctic (2.11 +/− 0.67 µg m−2). Across all stations and collection years, annual precipitation overwhelmingly controlled annual Hg deposition, explaining 73 % of the variability in observed annual Hg deposition. Our analyses further showed that annual Hg deposition loads across all five Alaska sites were consistently among the lowest in the United States, ranking in the lowest 1 to 5 percent of over 99 monitoring stations. Detailed back trajectory analyses showed diffuse source regions for most Hg deposition sites, which were almost identical with precipitation origins, suggesting global or regional Hg sources. One notable exception was Nome where we found pronounced differences between precipitation and Hg source origins with increased Hg contributions from the western Pacific Ocean downwind of East Asia. Analysis of multiple trace elements from Dutch Harbor, Nome, and Kodiak Island showed generally higher trace metal concentrations at the northern station Nome compared to Kodiak Island further to the south, with concentrations at Dutch Harbor falling in-between. Across all sites, we find two distinct groups of correlating elements: Cr and Ni and As and Pb. We attribute these associations to possibly different source origins, whereby sources of Ni and Cr may be derived from crustal (e.g., dust) sources while As and Pb may include long-range transport of anthropogenic pollution. Neither Hg nor any of the other trace elements analyzed, consistently associated with these two groups of elements, suggesting largely diffuse source origins. Calculations of enrichment factors (i.e., elemental enrichment compared to the upper continental crust) show low enrichment for Cr and Ni which is in support of a predominantly crustal source. High enrichment factors for Pb and Se are indicative of anthropogenic or additional natural sources for these elements. For most other elements including Hg, enrichment factors fell in-between these groups showing no clear source attribution to either crustal or anthropogenic source origins.

scholarly journals Atmospheric VOC measurements at a High Arctic site: characteristics and source apportionment

2020 ◽  
Author(s):  
Jakob B. Pernov ◽  
Rossana Bossi ◽  
Thibaut Lebourgeois ◽  
Jacob K. Nøjgaard ◽  
Rupert Holzinger ◽  
...  
Keyword(s):  
Source Apportionment ◽  
Biomass Burning ◽  
High Arctic ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Back Trajectory ◽  
Research Station ◽  
Source Regions ◽  
Arctic Haze

Abstract. There are few long-term datasets of volatile organic compounds (VOCs) in the High Arctic. Furthermore, knowledge about their source regions remains lacking. To address this matter, we report a long-term dataset of highly time-resolved VOC measurements in the High Arctic from April to October 2018. We have utilized a combination of measurement and modeling techniques to characterize the mixing ratios, temporal patterns, and sources of VOCs at Villum Research Station at Station Nord, in Northeast Greenland. Atmospheric VOCs were measured using Proton Transfer-Time of Flight-Mass Spectrometry (PTR-ToF-MS). Ten ions were selected for source apportionment with the receptor model, positive matrix factorization (PMF). A four-factor solution to the PMF model was deemed optimal. The factors identified were Biomass Burning, Marine Cryosphere, Background, and Arctic Haze. The Biomass Burning factor described the variation of acetonitrile and benzene. Back trajectory analysis indicated the influence of active fires in North America and Eurasia. The Marine Cryosphere factor was comprised of carboxylic acids (formic, acetic, and propionic acid) as well as dimethyl sulfide (DMS). This factor displayed a clear diurnal profile during periods of snow and sea ice melt. Back trajectories showed that the source regions for this factor were the coasts around North Greenland and the Arctic Ocean. The Background factor was temporally ubiquitous, with a slight decrease in the summer. This factor was not driven by any individual chemical species. The Arctic Haze factor was dominated by benzene with contributions from oxygenated VOCs. This factor exhibited a maximum in the spring and minima during the summer and autumn. This temporal pattern and species profile are indicative of anthropogenic sources in the mid-latitudes. This study provides seasonal characteristics and sources of VOCs and can help elucidate the processes affecting the atmospheric chemistry and biogeochemical feedback mechanisms in the High Arctic.

NEARSHORE OPERATIONS RESPONSE STRATEGY: Overcoming Spill Response Challenges in Remote Areas

2014 ◽  
Vol 2014 (1) ◽  
pp. 300126
Author(s):  
Mike Popovich ◽  
Tim L. Robertson ◽  
Gary Folley
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
The United States ◽  
Environmental Conservation ◽  
Coast Guard ◽  
Response Strategy ◽  
The Arctic ◽  
Remote Areas ◽  
Near Shore ◽  
Department Of Environmental Conservation

Conducting oil spill recovery operations in remote regions/environments is a daunting challenge. Increased shipping and oil exploration in the Arctic drives the need for developing innovative ways to mitigate oil spills in remote regions. This includes bolstering near-shore spill response to protect coastal resources. The Alaska Department of Environmental Conservation, in conjunction with the United States Coast Guard, and Alaska oil spill response organizations, has developed a Nearshore Operations Response Strategy (NORS) that provides planners and responders with a framework to plan for and carry out long-term oil removal and shoreline protection strategies in the Alaskan near-shore environment. NORS addresses the logistical challenges that exist when considering sustained operations in remote areas without shore-based support facilities. This strategy begins with tactics developed using best available technology to recover oil and protect resources in the near-shore environment. The components of a Nearshore Response Group designed to implement these tactics over a ten mile radius are described. Finally, the elements of a marine logistical base to support the Group for up to 21 days in remote regions are developed.

scholarly journals Ice-Breaking Fleets of the United States and Canada: Assessing the Current State of Affairs and Future Plans

2021 ◽  
Vol 13 (2) ◽  
pp. 703
Author(s):  
Megan Drewniak ◽  
Dimitrios Dalaklis ◽  
Anastasia Christodoulou ◽  
Rebecca Sheehan
Keyword(s):  
United States ◽  
The United States ◽  
Maritime Transportation ◽  
The Arctic ◽  
Polar Ice ◽  
Northwest Passage ◽  
Ice Cap ◽  
Ice Coverage ◽  
Current State ◽  
State Of Affairs

In recent years, a continuous decline of ice-coverage in the Arctic has been recorded, but these high latitudes are still dominated by earth’s polar ice cap. Therefore, safe and sustainable shipping operations in this still frozen region have as a precondition the availability of ice-breaking support. The analysis in hand provides an assessment of the United States’ and Canada’s polar ice-breaking program with the purpose of examining to what extent these countries’ relevant resources are able to meet the facilitated growth of industrial interests in the High North. This assessment will specifically focus on the maritime transportation sector along the Northwest Passage and consists of four main sections. The first provides a very brief description of the main Arctic passages. The second section specifically explores the current situation of the Northwest Passage, including the relevant navigational challenges, lack of infrastructure, available routes that may be used for transit, potential choke points, and current state of vessel activity along these routes. The third one examines the economic viability of the Northwest Passage compared to that of the Panama Canal; the fourth and final section is investigating the current and future capabilities of the United States’ and Canada’s ice-breaking fleet. Unfortunately, both countries were found to be lacking the necessary assets with ice-breaking capabilities and will need to accelerate their efforts in order to effectively respond to the growing needs of the Arctic. The total number of available ice-breaking assets is impacting negatively the level of support by the marine transportation system of both the United States and Canada; these two countries are facing the possibility to be unable to effectively meet the expected future needs because of the lengthy acquisition and production process required for new ice-breaking fleets.

scholarly journals The Northwest Passage in the Arctic: A Brief Assessment of the Relevant Marine Transportation System and Current Availability of Search and Rescue Services

Logistics ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 23
Author(s):  
Rebecca Sheehan ◽  
Dimitrios Dalaklis ◽  
Anastasia Christodoulou ◽  
Megan Drewniak ◽  
Peter Raneri ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Transportation System ◽  
Search And Rescue ◽  
Maritime Transportation ◽  
The Arctic ◽  
Marine Transportation ◽  
Northwest Passage ◽  
Traffic Routing ◽  
Brief Assessment

The analysis in hand provides a brief assessment of the United States’ and Canada’s marine transportation system and relevant search and rescue (SAR) support in relation to the Northwest Passage, with the purpose of examining to what extent these countries’ relevant infrastructure resources are able to meet the expected growth of shipping operations and business activities in the Arctic. Through an extensive literature review, this assessment will specifically describe the most important influences upon the maritime transportation system, with the issue of certain geographical details and the capabilities of existing ports standing out. Additionally, vessel activity trends and vessel traffic routing measure initiatives will be examined. Furthermore, the SAR infrastructure details and means to render assistance to people in distress along the Northwest Passage will be discussed. The reality remains that port characteristics are limited and vessel traffic routing measure initiatives and upgrades to SAR assets are commendable but slow-paced. It is true that both the United States and Canada are taking proper measures to build up infrastructure needs, but they both may run out of time to put adequate infrastructure in place to deal effectively with the changing environment.

Logistic problems in the Canadian Arctic

Polar Record ◽  
1961 ◽  
Vol 10 (67) ◽  
pp. 365-371
Author(s):  
T. A. Harwood
Keyword(s):  
United States ◽  
Canadian Arctic ◽  
The United States ◽  
The Arctic ◽  
Weather Bureau ◽  
Weather Stations ◽  
Resolute Bay ◽  
States Weather

In 1946 the United States Weather Bureau and the Canadian Meteorological Service installed the first of the Joint Arctic Weather Stations at Resolute Bay. The network of satellite stations was extended into the Arctic archipelago in the following years on roughly a 275-mile spacing to Mould Bay, Isachsen, Eureka and Alert.

scholarly journals Pan-Arctic aerosol number size distributions: seasonality and transport patterns

2017 ◽  
Vol 17 (13) ◽  
pp. 8101-8128 ◽  
Author(s):  
Eyal Freud ◽  
Radovan Krejci ◽  
Peter Tunved ◽  
Richard Leaitch ◽  
Quynh T. Nguyen ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Regional Scale ◽  
Arctic Region ◽  
The Arctic ◽  
Research Station ◽  
Size Distributions ◽  
Back Trajectories ◽  
Accumulation Mode ◽  
Source Regions ◽  
The Arctic Ocean

Abstract. The Arctic environment has an amplified response to global climatic change. It is sensitive to human activities that mostly take place elsewhere. For this study, a multi-year set of observed aerosol number size distributions in the diameter range of 10 to 500 nm from five sites around the Arctic Ocean (Alert, Villum Research Station – Station Nord, Zeppelin, Tiksi and Barrow) was assembled and analysed.A cluster analysis of the aerosol number size distributions revealed four distinct distributions. Together with Lagrangian air parcel back-trajectories, they were used to link the observed aerosol number size distributions with a variety of transport regimes. This analysis yields insight into aerosol dynamics, transport and removal processes, on both an intra- and an inter-monthly scale. For instance, the relative occurrence of aerosol number size distributions that indicate new particle formation (NPF) event is near zero during the dark months, increases gradually to  ∼ 40 % from spring to summer, and then collapses in autumn. Also, the likelihood of Arctic haze aerosols is minimal in summer and peaks in April at all sites.The residence time of accumulation-mode particles in the Arctic troposphere is typically long enough to allow tracking them back to their source regions. Air flow that passes at low altitude over central Siberia and western Russia is associated with relatively high concentrations of accumulation-mode particles (Nacc) at all five sites – often above 150 cm−3. There are also indications of air descending into the Arctic boundary layer after transport from lower latitudes.The analysis of the back-trajectories together with the meteorological fields along them indicates that the main driver of the Arctic annual cycle of Nacc, on the larger scale, is when atmospheric transport covers the source regions for these particles in the 10-day period preceding the observations in the Arctic. The scavenging of these particles by precipitation is shown to be important on a regional scale and it is most active in summer. Cloud processing is an additional factor that enhances the Nacc annual cycle.There are some consistent differences between the sites that are beyond the year-to-year variability. They are the result of differences in the proximity to the aerosol source regions and to the Arctic Ocean sea-ice edge, as well as in the exposure to free-tropospheric air and in precipitation patterns – to mention a few. Hence, for most purposes, aerosol observations from a single Arctic site cannot represent the entire Arctic region. Therefore, the results presented here are a powerful observational benchmark for evaluation of detailed climate and air chemistry modelling studies of aerosols throughout the vast Arctic region.

scholarly journals International Arctic Systems for Observing the Atmosphere: An International Polar Year Legacy Consortium

2016 ◽  
Vol 97 (6) ◽  
pp. 1033-1056 ◽  
Author(s):  
Taneil Uttal ◽  
Sandra Starkweather ◽  
James R. Drummond ◽  
Timo Vihma ◽  
Alexander P. Makshtas ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Satellite Observations ◽  
The Arctic ◽  
International Polar Year ◽  
Network Measurements ◽  
International Polar ◽  
In Situ Observations ◽  
Arctic Atmosphere

Abstract International Arctic Systems for Observing the Atmosphere (IASOA) activities and partnerships were initiated as a part of the 2007–09 International Polar Year (IPY) and are expected to continue for many decades as a legacy program. The IASOA focus is on coordinating intensive measurements of the Arctic atmosphere collected in the United States, Canada, Russia, Norway, Finland, and Greenland to create synthesis science that leads to an understanding of why and not just how the Arctic atmosphere is evolving. The IASOA premise is that there are limitations with Arctic modeling and satellite observations that can only be addressed with boots-on-the-ground, in situ observations and that the potential of combining individual station and network measurements into an integrated observing system is tremendous. The IASOA vision is that by further integrating with other network observing programs focusing on hydrology, glaciology, oceanography, terrestrial, and biological systems it will be possible to understand the mechanisms of the entire Arctic system, perhaps well enough for humans to mitigate undesirable variations and adapt to inevitable change.

THE ACTIVITIES OF THE USA AND CHINA IN THE REGIONS OF THE WORLD, AFFECTING THE REALIZATION OF RUSSIA'S INTERESTS. Part 1: country interests and activities

2021 ◽  
Vol 1 (10) ◽  
pp. 149-166
Author(s):  
Dmitry V. Gordienko ◽  
Keyword(s):  
United States ◽  
Russian Federation ◽  
The United States ◽  
Asia Pacific ◽  
The Arctic ◽  
The World ◽  
The Usa ◽  
The Russian Federation ◽  
The Military ◽  
The Impact

The paper examines the interests of Russia, the United States and China in the regions of the world and identifies the priorities of Russia's activities in Europe, Central Asia and the Caucasus, the Asia-Pacific region, the Arctic, Africa, the Middle East and Latin America, their comparative assessment with the interests of the United States and China. An approach to assessing the impact of possible consequences of the activities of the United States and China on the realization of Russia's interests is proposed. This makes it possible to identify the priorities of the policy of the Russian Federation in various regions of the world. The results of the analysis can be used to substantiate recommendations to the military-political leadership of our country. It is concluded that the discrepancy between the interests of the United States and China is important for the implementation of the current economic and military policy of the Russian Federation.

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