scholarly journals Ten-year trends of atmospheric mercury in the high Arctic compared to Canadian sub-Arctic and mid-latitude sites

2013 ◽  
Vol 13 (3) ◽  
pp. 1535-1545 ◽  
Author(s):  
A. S. Cole ◽  
A. Steffen ◽  
K. A. Pfaffhuber ◽  
T. Berg ◽  
M. Pilote ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
High Arctic ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Gaseous Mercury ◽  
Time Period ◽  
Long Term Trends ◽  
Arctic Atmosphere ◽  
Global Emissions

Abstract. Global emissions of mercury continue to change at the same time as the Arctic is experiencing ongoing climatic changes. Continuous monitoring of atmospheric mercury provides important information about long-term trends in the balance between transport, chemistry, and deposition of this pollutant in the Arctic atmosphere. Ten-year records of total gaseous mercury (TGM) from 2000 to 2009 were analyzed from two high Arctic sites at Alert (Nunavut, Canada) and Zeppelin Station (Svalbard, Norway); one sub-Arctic site at Kuujjuarapik (Nunavik, Québec, Canada); and three temperate Canadian sites at St. Anicet (Québec), Kejimkujik (Nova Scotia) and Egbert (Ontario). Five of the six sites examined showed a decreasing trend over this time period. Overall trend estimates at high latitude sites were: −0.9% yr−1 (95% confidence limits: −1.4, 0) at Alert and no trend (−0.5, +0.7) at Zeppelin Station. Faster decreases were observed at the remainder of the sites: −2.1% yr−1 (−3.1, −1.1) at Kuujjuarapik, −1.9% yr−1 (−2.1, −1.8) at St. Anicet, −1.6% yr−1 (−2.4, −1.0) at Kejimkujik and −2.2% yr−1 (−2.8, −1.7) at Egbert. Trends at the sub-Arctic and mid-latitude sites agree with reported decreases in background TGM concentration since 1996 at Mace Head, Ireland, and Cape Point, South Africa, but conflict with estimates showing an increase in global anthropogenic emissions over a similar period. Trends in TGM at the two high Arctic sites were not only less negative (or neutral) overall but much more variable by season. Possible reasons for differences in seasonal and overall trends at the Arctic sites compared to those at lower latitudes are discussed, as well as implications for the Arctic mercury cycle. The first calculations of multi-year trends in reactive gaseous mercury (RGM) and total particulate mercury (TPM) at Alert were also performed, indicating increases from 2002 to 2009 in both RGM and TPM in the spring when concentrations are highest.

scholarly journals Ten-year trends of atmospheric mercury in the high Arctic compared to Canadian sub-Arctic and mid-latitude sites

2012 ◽  
Vol 12 (8) ◽  
pp. 20209-20237 ◽  
Author(s):  
A. S. Cole ◽  
A. Steffen ◽  
K. Aspmo Pfaffhuber ◽  
T. Berg ◽  
M. Pilote ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
High Arctic ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Gaseous Mercury ◽  
Time Period ◽  
Long Term Trends ◽  
Arctic Atmosphere ◽  
Global Emissions

Abstract. Global emissions of mercury continue to change at the same time as the Arctic is experiencing ongoing climatic changes. Continuous monitoring of atmospheric mercury provides important information about long-term trends in the balance between transport, chemistry, and deposition of this pollutant in the Arctic atmosphere. Ten-year records of total gaseous mercury (TGM) were analyzed from two high Arctic sites at Alert (Nunavut, Canada) and Zeppelin Station (Svalbard, Norway); one sub-Arctic site at Kuujjuarapik (Nunavik, Québec, Canada); and three temperate Canadian sites at St. Anicet (Québec), Kejimkujik (Nova Scotia) and Egbert (Ontario). Five of the six sites examined show a decreasing trend over this time period. Overall trend estimates at high latitude sites were: −0.9% yr−1 (95% confidence limits: −1.4, 0) at Alert and no trend (−0.5, +0.7) at Zeppelin Station. Faster decreases were observed at the remainder of the sites: −2.1% yr−1 (−3.1, −1.1) at Kuujjuarapik, −1.9% yr−1 (−2.1, −1.8) at St. Anicet, −1.6% yr−1 (−2.4, −1.0) at Kejimkujik and −2.2% yr−1 (−2.8, −1.7) at Egbert. Trends at the sub-Arctic and mid-latitude sites agree with reported decreases in background TGM concentration since 1996 at Mace Head, Ireland, and Cape Point, South Africa, but conflict with estimates showing an increase in global anthropogenic emissions over a similar period. Trends in TGM at the two high Arctic sites were not only less negative (or neutral) overall but much more variable by season. Possible reasons for differences in seasonal and overall trends at the Arctic sites compared to those at lower latitudes are discussed, as well as implications for the Arctic mercury cycle. The first calculations of multi-year trends in reactive gaseous mercury (RGM) and total particulate mercury (TPM) at Alert were also performed, indicating increases from 2002 to 2009 in both RGM and TPM in the spring when concentrations are highest.

Long-term trends in temperature of the Arctic atmosphere and their relation to variations of solar activity

2006 ◽  
Vol 31 (1-3) ◽  
pp. 94-98
Author(s):  
A.V. Shirochkov ◽  
L.N. Makarova ◽  
V.V. Maystrova ◽  
A.P. Nagurny
Keyword(s):  
Solar Activity ◽  
The Arctic ◽  
Long Term Trends ◽  
Arctic Atmosphere

scholarly journals Assessing volumetric change distributions and scaling relations of retrogressive thaw slumps across the Arctic

2022 ◽  
Vol 16 (1) ◽  
pp. 1-15
Author(s):  
Philipp Bernhard ◽  
Simon Zwieback ◽  
Nora Bergner ◽  
Irena Hajnsek
Keyword(s):  
Regional Differences ◽  
Scaling Laws ◽  
Remote Sensing Data ◽  
High Arctic ◽  
The Arctic ◽  
Scaling Relations ◽  
Volumetric Change ◽  
Inverse Gamma ◽  
Time Period ◽  
Study Sites

Abstract. Arctic ice-rich permafrost is becoming increasingly vulnerable to terrain-altering thermokarst, and among the most rapid and dramatic of these changes are retrogressive thaw slumps (RTSs). They initiate when ice-rich soils are exposed and thaw, leading to the formation of a steep headwall which retreats during the summer months. The impacts and the distribution and scaling laws governing RTS changes within and between regions are unknown. Using TanDEM-X-derived digital elevation models, we estimated RTS volume and area changes over a 5-year time period from winter 2011/12 to winter 2016/17 and used for the first time probability density functions to describe their distributions. We found that over this time period all 1853 RTSs mobilized a combined volume of 17×106 m3 yr−1, corresponding to a volumetric change density of 77 m3 yr−1 km−2. Our remote sensing data reveal inter-regional differences in mobilized volumes, scaling laws, and terrain controls. The distributions of RTS area and volumetric change rates follow an inverse gamma function with a distinct peak and an exponential decrease for the largest RTSs. We found that the distributions in the high Arctic are shifted towards larger values than at other study sites We observed that the area-to-volume scaling was well described by a power law with an exponent of 1.15 across all study sites; however the individual sites had scaling exponents ranging from 1.05 to 1.37, indicating that regional characteristics need to be taken into account when estimating RTS volumetric changes from area changes. Among the terrain controls on RTS distributions that we examined, which included slope, adjacency to waterbodies, and aspect, the latter showed the greatest but regionally variable association with RTS occurrence. Accounting for the observed regional differences in volumetric change distributions, scaling relations, and terrain controls may enhance the modelling and monitoring of Arctic carbon, nutrient, and sediment cycles.

Comparison of the Long-Term Trends of the Largest Waves in the Ice-Free Arctic Waters From Different Reanalysis Products

2018 ◽  
Author(s):  
Takuji Waseda ◽  
Takehiko Nose ◽  
Adrean Webb
Keyword(s):  
Arctic Ocean ◽  
The Arctic ◽  
Extreme Value Analysis ◽  
Positive Trend ◽  
Value Analysis ◽  
The Arctic Ocean ◽  
Ship Route ◽  
Long Term Trends ◽  
Horizontal Grid

The long-term trends of the expected largest waves in the ice-free Arctic waters from Laptev to Beaufort Seas was studied analyzing the ERA-interim reanalysis from 1979 to 2016. The analysis showed that the positive trend is largest in October and increased almost 70 cm in 38 years. For ships navigating the Northern Ship Route, it is important to know what the possible largest waves to expect during its cruise. In view of conducting the extreme value analysis, the uncertainty of the largest wave needs to be validated. However, the observation in the Arctic Ocean is limited. We, therefore, rely on the reanalysis wave products in the Arctic Ocean, whose uncertainty is yet to be determined. ERA-Interim and ERA-5 are compared in the Laptev, the East Siberian, Chukchi and Beaufort Seas. The comparison is relevant as the two products differ in its horizontal grid resolution and availability of the satellite altimeter significant wave height data assimilation. During 2010–2016 when the ERA5 is available, only a small difference from ERA-Interim was detected in the mean. However, the expected largest waves in the domain tended to be large for the ERA-5, 8% normalized bias. The tendency was quite similar with a high correlation of 0.98.

scholarly journals Record high peaks in PCB concentrations in the Arctic atmosphere due to long-range transport of biomass burning emissions

2007 ◽  
Vol 7 (17) ◽  
pp. 4527-4536 ◽  
Author(s):  
S. Eckhardt ◽  
K. Breivik ◽  
S. Manø ◽  
A. Stohl
Keyword(s):  
Biomass Burning ◽  
Dry Matter ◽  
The Arctic ◽  
Pcb Congeners ◽  
Range Transport ◽  
Standard Deviations ◽  
High Concentrations ◽  
Arctic Atmosphere ◽  
Primary Emissions

Abstract. Soils and forests in the boreal region of the Northern Hemisphere are recognised as having a large capacity for storing air-borne Persistent Organic Pollutants (POPs), such as the polychlorinated biphenyls (PCBs). Following reductions of primary emissions of various legacy POPs, there is an increasing interest and debate about the relative importance of secondary re-emissions on the atmospheric levels of POPs. In spring of 2006, biomass burning emissions from agricultural fires in Eastern Europe were transported to the Zeppelin station on Svalbard, where record-high levels of many air pollutants were recorded (Stohl et al., 2007). Here we report on the extremely high concentrations of PCBs that were also measured during this period. 21 out of 32 PCB congeners were enhanced by more than two standard deviations above the long-term mean concentrations. In July 2004, about 5.8 million hectare of boreal forest burned in North America, emitting a pollution plume which reached the Zeppelin station after a travel time of 3–4 weeks (Stohl et al., 2006). Again, 12 PCB congeners were elevated above the long-term mean by more than two standard deviations, with the less chlorinated congeners being most strongly affected. We propose that these abnormally high concentrations were caused by biomass burning emissions. Based on enhancement ratios with carbon monoxide and known emissions factors for this species, we estimate that 130 and 66 μg PCBs were released per kilogram dry matter burned, respectively. To our knowledge, this is the first study relating atmospheric PCB enhancements with biomass burning. The strong effects on observed concentrations far away from the sources, suggest that biomass burning is an important source of PCBs for the atmosphere.

scholarly journals Wave Climate from Spectra and Its Connections with Local and Remote Wind Climate

2019 ◽  
Vol 49 (2) ◽  
pp. 543-559 ◽  
Author(s):  
Haoyu Jiang ◽  
Lin Mu
Keyword(s):  
Wind Field ◽  
Wave Climate ◽  
The Arctic ◽  
Target Point ◽  
Wave Spectra ◽  
Basin Scale ◽  
Long Term Trends ◽  
Wind Climate ◽  
Climate Systems

AbstractWind-generated waves can propagate over large distances. Therefore, wave spectra from a fixed point can record information about air–sea interactions in distant areas. In this study, the spectral wave climate for a point in the tropical eastern Pacific Ocean is computed. Several well-defined wave climate systems are observed in the mean wave spectrum. Significant seasonal cycling, long-term trends, and correlations with the Southern Oscillation, the Arctic Oscillation, and the Antarctic Oscillation are observed in the local wave spectra, showing abundant climatic information. Projections of wind vectors on the directions pointing to the target location are used to connect the spectral wave climate and basin-scale wind climate, because significant correlations are observed between the wave spectra and the wind projections of both local and remote wind systems. The origins of all the identified wave climate systems, including the westerlies and the trade winds in both hemispheres, are clearly shown in wind projection maps. Some of these origins are thousands of kilometers away from the target point, demonstrating the validity of this connection. Comparisons are made between wave spectra and the corresponding local and remote wind fields with respect to seasonal and interannual variability and long-term trends. The results show that each frequency and direction of ocean wave spectra at a certain location can be approximately linked to the wind field for a geographical area, implying that it is feasible to reconstruct spectral wave climates from observational wind field data and monitor wind climates from observational wave spectra geographically far away.

scholarly journals Temporal and spatial analysis of ozone concentrations in Europe based on time scale decomposition and a multi-clustering approach

2019 ◽  
Author(s):  
Eirini Boleti ◽  
Christoph Hueglin ◽  
Stuart K. Grange ◽  
André S. H. Prévôt ◽  
Satoshi Takahama
Keyword(s):  
Time Scale ◽  
Seasonal Cycle ◽  
Clustering Algorithm ◽  
Short Term ◽  
Ozone Concentrations ◽  
Time Period ◽  
Term Variation ◽  
Long Term Trends ◽  
Time Scale Decomposition

Abstract. Air quality measures that were implemented in Europe in the 1990s resulted in reductions of ozone precursors concentrations. In this study, the effect of these reductions on ozone is investigated by analyzing surface measurements of ozone for the time period between 2000 and 2015. Using a non-parametric time scale decomposition methodology, the long-term, seasonal and short-term variation of ozone observations were extracted. A clustering algorithm was applied to the different time scale variations, leading to a classification of sites across Europe based on the temporal characteristics of ozone. The clustering based on the long-term variation resulted in a site type classification, while a regional classification was obtained based on the seasonal and short-term variations. Long-term trends of de-seasonalized mean and meteo-adjusted peak ozone concentrations were calculated across large parts of Europe for the time period 2000–2015. A multi-dimensional scheme was used for a detailed trend analysis, based on the identified clusters, which reflect precursor emissions and meteorological influence either on the inter-annual or the short-term time scale. Decreasing mean ozone concentrations at rural sites and increasing or stabilizing at urban sites were observed. At the same time downward trends for peak ozone concentrations were detected for all site types. The effect of hemispheric transport of ozone can be seen either in regions affected by synoptic patterns in the northern Atlantic or at sites located at remote high altitude locations. In addition, a reduction of the amplitude in the seasonal cycle of ozone was observed, and a shift in the occurrence of the seasonal maximum towards earlier time of the year. Finally, a reduced sensitivity of ozone to temperature was identified. It was concluded that long-term trends of mean and peak ozone concentrations are mostly controlled by precursors emissions changes, while seasonal cycle trends and changes in the sensitivity of ozone to temperature are driven by regional climatic conditions.

scholarly journals Atmospheric mercury observations from Antarctica: seasonal variation and source and sink region calculations

2012 ◽  
Vol 12 (7) ◽  
pp. 3241-3251 ◽  
Author(s):  
K. A. Pfaffhuber ◽  
T. Berg ◽  
D. Hirdman ◽  
A. Stohl
Keyword(s):  
Southern Hemisphere ◽  
Dispersion Model ◽  
Particle Dispersion ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Research Station ◽  
The Mean ◽  
The Antarctic ◽  
Source And Sink

Abstract. Long term atmospheric mercury measurements in the Southern Hemisphere are scarce and in Antarctica completely absent. Recent studies have shown that the Antarctic continent plays an important role in the global mercury cycle. Therefore, long term measurements of gaseous elemental mercury (GEM) were initiated at the Norwegian Antarctic Research Station, Troll (TRS) in order to improve our understanding of atmospheric transport, transformation and removal processes of GEM. GEM measurements started in February 2007 and are still ongoing, and this paper presents results from the first four years. The mean annual GEM concentration of 0.93 ± 0.19 ng m−3 is in good agreement with other recent southern-hemispheric measurements. Measurements of GEM were combined with the output of the Lagrangian particle dispersion model FLEXPART, for a statistical analysis of GEM source and sink regions. It was found that the ocean is a source of GEM to TRS year round, especially in summer and fall. On time scales of up to 20 days, there is little direct transport of GEM to TRS from Southern Hemisphere continents, but sources there are important for determining the overall GEM load in the Southern Hemisphere and for the mean GEM concentration at TRS. Further, the sea ice and marginal ice zones are GEM sinks in spring as also seen in the Arctic, but the Antarctic oceanic sink seems weaker. Contrary to the Arctic, a strong summer time GEM sink was found, when air originates from the Antarctic plateau, which shows that the summertime removal mechanism of GEM is completely different and is caused by other chemical processes than the springtime atmospheric mercury depletion events. The results were corroborated by an analysis of ozone source and sink regions.

STRATEGIC OPPORTUNITIES OF DEVELOPMENT OF INTERNATIONAL RELATIONS IN THE ARCTIC

2016 ◽  
Vol 11 (1) ◽  
pp. 114-119
Author(s):  
Медведев ◽  
Dmitriy Medvedev
Keyword(s):  
International Relations ◽  
Political Development ◽  
The Arctic ◽  
Security Dilemma ◽  
Security Environment ◽  
Political Cooperation ◽  
Long Term Trends ◽  
Development Prospects ◽  
Foreign Policy Strategies

The article describes the long-term trends in the development of international relations in the Arctic, the strategic importance of the region in modern international relations is proved. By analyzing the foreign policy strategies of the polar states the possible directions of international cooperation are formulated, threats to the development of constructive cooperation in the region are identified. The trends and key integration structures of military and political cooperation in the region are described, for the study of development prospects of the situation the concept of «security dilemma» is applied. The author describes the conditions necessary to reduce the tension in the region and the establishment of a non-confrontational model of world political development in the Arctic. In particular, the recognition of insolvency of isolation policy, as well as the rejection of the fragmentation of international security environment in the Arctic will allow to overcome the destructive tendencies of development and increase the possibility to maintain a mutually acceptable dialogue.

scholarly journals Dynamics of gaseous oxidized mercury at Villum Research Station during the High Arctic summer

2021 ◽  
Vol 21 (17) ◽  
pp. 13287-13309
Author(s):  
Jakob Boyd Pernov ◽  
Bjarne Jensen ◽  
Andreas Massling ◽  
Daniel Charles Thomas ◽  
Henrik Skov
Keyword(s):  
General Pattern ◽  
Ground Level ◽  
High Arctic ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Research Station ◽  
Cold Temperatures ◽  
Air Masses ◽  
Arctic Summer ◽  
Gaseous Oxidized Mercury

Abstract. While much research has been devoted to the subject of gaseous elemental mercury (GEM) and gaseous oxidized mercury (GOM) in the Arctic spring during atmospheric mercury depletion events, few studies have examined the behavior of GOM in the High Arctic summer. GOM, once deposited and incorporated into the ecosystem, can pose a threat to human and wildlife health, though there remain large uncertainties regarding the transformation, deposition, and assimilation of mercury into the food web. Therefore, to further our understanding of the dynamics of GOM in the High Arctic during the late summer, we performed measurements of GEM and GOM, along with meteorological parameters and atmospheric constituents, and utilized modeled air mass history during two summer campaigns in 2019 and 2020 at Villum Research Station (Villum) in northeastern Greenland. Seven events of enhanced GOM concentrations were identified and investigated in greater detail. In general, the common factors associated with event periods at ground level were higher levels of radiation and lower H2O mixing ratios, accumulated precipitation, and relative humidity (RH), although none were connected with cold temperatures. Non-event periods at ground level each displayed a different pattern in one or more parameters when compared to event periods. Generally, air masses during event periods for both campaigns were colder and drier, arrived from higher altitudes, and spent more time above the mixed layer and less time in a cloud compared to non-events, although some events deviated from this general pattern. Non-event air masses displayed a different pattern in one or more parameters when compared to event periods, although they were generally warmer and wetter and arrived from lower altitudes with little radiation. Coarse-mode aerosols were hypothesized to provide the heterogenous surface for halogen propagation during some of the events, while for others the source is unknown. While these general patterns were observed for event and non-event periods, analysis of individual events showed more specific origins. Five of the seven events were associated with air masses that experienced similar conditions: transported from the cold, dry, and sunlit free troposphere. However, two events experienced contrasting conditions, with air masses being warm and wet with surface layer contact under little radiation. Two episodes of extremely high levels of NCoarse and BC, which appear to originate from flaring emissions in Russia, did not contribute to enhanced GOM levels. This work aims to provide a better understanding of the dynamics of GOM during the High Arctic summer.

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