scholarly journals <sup>222</sup>Rn calibrated mercury fluxes from terrestrial surface of southern Africa derived from observations at Cape Point, South Africa

2013 ◽  
Vol 13 (3) ◽  
pp. 8213-8231
Author(s):  
F. Slemr ◽  
E.-G. Brunke ◽  
S. Whittlestone ◽  
W. Zahorowski ◽  
R. Ebinghaus ◽  
...  
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Standard Error ◽  
Wet Deposition ◽  
Emission Rate ◽  
Elemental Mercury ◽  
Gaseous Elemental Mercury ◽  
Emission Ratio ◽  
Mercury Fluxes ◽  
Almost All

Abstract. Gaseous elemental mercury (GEM) and 222Rn, a radioactive gas of primarily terrestrial origin with a half-life of 3.8 days, have been measured simultaneously at Cape Point, South Africa, since March 2007. Between March 2007 and December 2011 altogether 191 events with high 222Rn concentrations were identified. GEM correlated with 222Rn in 94 of the events and was constant during almost all the remaining events without significant correlation. The average GEM/222Rn emission ratio of all events including the non-significant ones was −0.0001 &amp;pm; 0.0030 pg mBq−1, with 0.0030 pg mBq−1 being the standard error of the average. With an emission rate of 1.1 222Rn atoms cm−2 s−1 and a correction for the transport duration, this emission ratio corresponds to a radon calibrated flux of about −0.01 ng GEM m−2 h−1 with a standard error of &amp;pm;0.34 ng GEM m−2 h−1 (n = 191). With wet deposition, which is not included in this estimate, the terrestrial surface of southern Africa seems to be a net mercury sink of about −1.01 ng m−2 h−1.

scholarly journals <sup>222</sup>Rn-calibrated mercury fluxes from terrestrial surface of southern Africa

2013 ◽  
Vol 13 (13) ◽  
pp. 6421-6428 ◽  
Author(s):  
F. Slemr ◽  
E.-G. Brunke ◽  
S. Whittlestone ◽  
W. Zahorowski ◽  
R. Ebinghaus ◽  
...  
Keyword(s):  
Southern Africa ◽  
Standard Error ◽  
Emission Rate ◽  
Flux Ratio ◽  
Elemental Mercury ◽  
Additional Contribution ◽  
Transport Time ◽  
Event Duration ◽  
Gaseous Elemental Mercury ◽  
Almost All

Abstract. Gaseous elemental mercury (GEM) and 222Rn, a radioactive gas of primarily terrestrial origin with a half-life of 3.8 days, have been measured simultaneously at Cape Point, South Africa, since March 2007. Between March 2007 and December 2011, altogether 191 events with high 222Rn concentrations were identified. GEM correlated with 222Rn in 94 of the events and was constant during almost all the remaining events without significant correlation. The average GEM / 222Rn flux ratio of all events including the non-significant ones was −0.0001 with a standard error of ±0.0030 pg mBq−1. Weighted with the event duration, the average GEM / 222Rn flux ratio was −0.0048 ± 0.0011 pg mBq−1. With an emission rate of 1.1 222Rn atoms cm−2 s−1 and a correction for the transport time, this flux ratio corresponds to a radon-calibrated flux of about −0.54 ng GEM m−2 h−1 with a standard error of ±0.13 ng GEM m−2 h−1 (n = 191). With wet deposition, which is not included in this estimate, the terrestrial surface of southern Africa seems to be a net mercury sink of about −1.55 ng m−2 h−1. The additional contribution of an unknown but presumably significant deposition of reactive gaseous mercury would further increase this sink.

scholarly journals Trend of atmospheric mercury concentrations at Cape Point for 1995–2004 and since 2007

2016 ◽  
Author(s):  
Lynwill G. Martin ◽  
Casper Labuschagne ◽  
Ernst-Günther Brunke ◽  
Andreas Weigelt ◽  
Ralf Ebinghaus ◽  
...  
Keyword(s):  
South Africa ◽  
Biomass Burning ◽  
Wet Deposition ◽  
Elemental Mercury ◽  
Atmospheric Mercury ◽  
Austral Spring ◽  
Mercury Emissions ◽  
Gaseous Elemental Mercury ◽  
Regional Processes

Abstract. Long-term measurements of gaseous elemental mercury (GEM) concentrations at Cape Point, South Africa, reveal a downward trend between September 1995 and December 2005 and an upward one since March 2007 until June 2015 implying a change in trend sign between 2004 and 2007. The trend change is qualitatively consistent with the trend changes in GEM concentrations observed at Mace Head, Ireland, and in mercury wet deposition over North America suggesting a change in worldwide mercury emissions. Seasonally resolved trends suggest a modulation of the overall trend by regional processes. The trends in absolute terms (downward in 1995–2004 and upward in 2007–2015) are the highest in austral spring (SON) coinciding with the peak in emissions from biomass burning in South America and southern Africa. The influence of trends in biomass burning is further supported by a biennial variation in GEM concentration found here and an ENSO signature in GEM concentrations reported recently.

scholarly journals Emissions of mercury in Southern Africa derived from long-term observations at Cape Point, South Africa

2012 ◽  
Vol 12 (5) ◽  
pp. 11079-11103
Author(s):  
E.-G. Brunke ◽  
R. Ebinghaus ◽  
H. H. Kock ◽  
C. Labuschagne ◽  
F. Slemr
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Elemental Mercury ◽  
Mercury Emission ◽  
Mercury Emissions ◽  
Gaseous Elemental Mercury ◽  
Term Monitoring ◽  
Co Emission ◽  
Emission Ratios

Abstract. Mercury emissions in South Africa have so far been estimated only by a bottom-up approach from activities and emission factors for different processes. In this paper we derive GEM/CO (GEM being gaseous elemental mercury, Hg0), GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios from plumes observed during long-term monitoring of these species at Cape Point between March 2007 and December 2009. The average observed GEM/CO, GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios were 2.40 ± 2.65 pg m−3 ppb−1 (n = 47), 62.7 ± 80.2 pg m−3 ppb−1 (n = 44), 3.61 ± 4.66 pg m−3 ppb−1 (n = 46), 35.6 ± 25.4 ppb ppm−1 (n = 52), 20.2 ± 15.5 ppb ppm−1 (n=48), and 0.876 ± 1.106 ppb ppm−1 (n=42), respectively. The observed CO/CO2, CH4/CO2, and CH4/CO emission ratios agree within the combined uncertainties of the observations and emissions with the ratios calculated from EDGAR (version 4.2) CO2, CO, and CH4 inventories for South Africa and Southern Africa (South Africa, Lesotho, Swaziland, Namibia, Botswana, Zimbabwe, and Mozambique) in 2007 and 2008 (inventories for 2009 are not available yet). Total elemental mercury emission of 13.1, 15.2, and 16.1 t Hg yr−1 are estimated independently using the GEM/CO, GEM/CO2, and GEM/CH4 emission ratios and the annual mean CO, CO2, and CH4 emissions, respectively, of South Africa in 2007 and 2008. The average of these independent estimates of 14.8 ± 1.5 t GEM yr−1 is much less than the total emission of 257 t Hg yr−1 from older inventories. Considering that emission of GEM represents only 50–78% of all mercury emissions, our estimates come close to the total mercury emission estimates ranging between 40–50 t Hg yr−1 from more recent inventories.

Southern Africa: Regional Politics and Dynamics

2019 ◽  
Author(s):  
Stephen Chan
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Ethnic Diversity ◽  
Regional Politics ◽  
New Era ◽  
Truth And Reconciliation ◽  
Dominant Party ◽  
Contemporary Politics ◽  
The 1960S ◽  
Almost All

Southern Africa is a region marked by huge tensions caused by the longevity of colonial rule and racial discrimination. Angola, Mozambique, Zimbabwe, and South Africa all achieved independence only years after most of Africa, and only with protracted militarized struggle. Even those countries that did enter independence in the 1960s, alongside most of Africa, were marked by the struggles of their neighbors—Zambia, host to exile liberation movements, was a frequent military target; and wars, sponsored or supported by apartheid South Africa, continued to rage in Angola and Mozambique even after they achieved independence. This has marked the post-independence politics of most countries of the region, almost all of whom have gone through, or remain within, an era of one-party politics or dominant party rule. In part, this can be read as a residual longing for stability. In other part it can be read as a “liberation generation” using its history as a lever by which to hang onto power. Having said that, the politics of each country has distinctive characteristics—although one has certainly been protracted effort to adhere to forms of ethics, such as “Humanism” in Zambia, and truth and reconciliation in South Africa. The contemporary politics of the region, however, is one with forms of authoritarianism and corruption and, in many cases, economic decline or turmoil. The rise of Chinese influence is also a new marker of politics in the region as all of Southern Africa, with many different former colonial powers, enters a new era of problematic cosmopolitanism—with the international jostling with already sometimes-volatile elements of ethnic diversity, balancing, and conflict.

scholarly journals 222Rn calibrated mercury fluxes from terrestrial surfaces of southern Africa derived from observations at Cape Point, South Africa

2013 ◽  
Vol 1 ◽  
pp. 17005
Author(s):  
F. Slemr ◽  
E.-G. Brunke ◽  
S. Whittlestone ◽  
W. Zahorowski ◽  
R. Ebinghaus ◽  
...  
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Mercury Fluxes

scholarly journals Emissions of mercury in southern Africa derived from long-term observations at Cape Point, South Africa

2012 ◽  
Vol 12 (16) ◽  
pp. 7465-7474 ◽  
Author(s):  
E.-G. Brunke ◽  
R. Ebinghaus ◽  
H. H. Kock ◽  
C. Labuschagne ◽  
F. Slemr
Keyword(s):  
South Africa ◽  
Southern Africa ◽  
Electricity Consumption ◽  
Elemental Mercury ◽  
Emission Inventories ◽  
Pronounced Difference ◽  
Mercury Emissions ◽  
Co Emission ◽  
Emission Ratios

Abstract. Mercury emissions in South Africa have so far been estimated only by a bottom-up approach from activities and emission factors for different processes. In this paper we derive GEM/CO (GEM being gaseous elemental mercury, Hg0), GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios from plumes observed during long-term monitoring of these species at Cape Point between March 2007 and December 2009. The average observed GEM/CO, GEM/CO2, GEM/CH4, CO/CO2, CH4/CO2, and CH4/CO emission ratios were 2.40 ± 2.65 pg m−3 ppb−1 (n = 47), 62.7 ± 80.2 pg m−3 ppm−1 (n = 44), 3.61 ± 4.66 pg m−3 ppb−1 (n = 46), 35.6 ± 25.4 ppb ppm−1 (n = 52), 20.2 ± 15.5 ppb ppm−1 (n = 48), and 0.876 ± 1.106 ppb ppb−1 (n = 42), respectively. The observed CO/CO2, CH4/CO2, and CH4/CO emission ratios agree within the combined uncertainties of the observations and emissions with the ratios calculated from EDGAR (version 4.2) CO2, CO, and CH4 inventories for South Africa and southern Africa (South Africa, Lesotho, Swaziland, Namibia, Botswana, Zimbabwe, and Mozambique) in 2007 and 2008 (inventories for 2009 are not available yet). Total elemental mercury emission of 13.1, 15.2, and 16.1 t Hg yr−1 are estimated independently using the GEM/CO, GEM/CO2, and GEM/CH4 emission ratios and the annual mean CO, CO2, and CH4 emissions, respectively, of South Africa in 2007 and 2008. The average of these independent estimates of 14.8 t GEM yr−1 is much less than the total emission of 257 t Hg yr−1 shown by older inventories which are now considered to be wrong. Considering the uncertainties of our emission estimate, of the emission inventories, and the fact that emission of GEM represents 50–78 % of all mercury emissions, our estimate is comparable to the currently cited GEM emissions in 2004 and somewhat smaller than emissions in 2006. A further increase of mercury emissions due to increasing electricity consumption will lead to a more pronounced difference. A quantitative assessment of the difference and its significance, however, will require emission inventories for the years of observations (2007–2009) as well as better data on the speciation of the total mercury emissions in South Africa.

scholarly journals Statistical exploration of gaseous elemental mercury (GEM) measured at Cape Point from 2007 to 2011

2015 ◽  
Vol 15 (18) ◽  
pp. 10271-10280 ◽  
Author(s):  
A. D. Venter ◽  
J. P. Beukes ◽  
P. G. van Zyl ◽  
E.-G. Brunke ◽  
C. Labuschagne ◽  
...  
Keyword(s):  
South Africa ◽  
Urban Areas ◽  
Calculated Data ◽  
Elemental Mercury ◽  
Back Trajectory ◽  
Cluster Solution ◽  
Atmospheric Parameters ◽  
Air Mass ◽  
Gaseous Elemental Mercury ◽  
Gem Data

Abstract. The authors evaluated continuous high-resolution gaseous elemental mercury (GEM) data from the Cape Point Global Atmosphere Watch (CPT GAW) station with different statistical analysis techniques. GEM data were evaluated by cluster analysis and the results indicated that two clusters, separated at 0.904 ng m−3, existed. The air mass history for the two-cluster solution was investigated by means of back-trajectory analysis. The air mass back-trajectory net result showed lower GEM concentrations originating from the sparsely populated semi-arid interior of South Africa and the marine environment, whereas higher GEM concentrations originated predominately along the coast of South Africa that most likely coincide with trade routes and industrial activities in urban areas along the coast. Considering the net result from the air mass back-trajectories, it is evident that not all low GEM concentrations are from marine origin, and similarly, not all high GEM concentrations have a terrestrial origin. Equations were developed by means of multi-linear regression (MLR) analysis that allowed for the estimation and/or prediction of atmospheric GEM concentrations from other atmospheric parameters measured at the CPT GAW station. These equations also provided some insight into the relation and interaction of GEM with other atmospheric parameters. Both measured and MLR calculated data confirm a decline in GEM concentrations at CPT GAW over the period evaluated.

scholarly journals Trend of atmospheric mercury concentrations at Cape Point for 1995–2004 and since 2007

2017 ◽  
Vol 17 (3) ◽  
pp. 2393-2399 ◽  
Author(s):  
Lynwill G. Martin ◽  
Casper Labuschagne ◽  
Ernst-Günther Brunke ◽  
Andreas Weigelt ◽  
Ralf Ebinghaus ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Wet Deposition ◽  
Southern Oscillation ◽  
Elemental Mercury ◽  
Atmospheric Mercury ◽  
Austral Spring ◽  
Mercury Emissions ◽  
Gaseous Elemental Mercury ◽  
Regional Processes

Abstract. Long-term measurements of gaseous elemental mercury (GEM) concentrations at Cape Point, South Africa, reveal a downward trend between September 1995 and December 2005 and an upward one from March 2007 until June 2015, implying a change in trend sign between 2004 and 2007. The trend change is qualitatively consistent with the trend changes in GEM concentrations observed at Mace Head, Ireland, and in mercury wet deposition over North America, suggesting a change in worldwide mercury emissions. Seasonally resolved trends suggest a modulation of the overall trend by regional processes. The trends in absolute terms (downward in 1995–2004 and upward in 2007–2015) are highest in austral spring (SON), coinciding with the peak in emissions from biomass burning in South America and southern Africa. The influence of trends in biomass burning is further supported by a biennial variation in GEM concentration found here and an El Niño–Southern Oscillation (ENSO) signature in GEM concentrations reported recently.

scholarly journals Importance of Gaseous Elemental Mercury Fluxes in Western Maryland

Atmosphere ◽  
2016 ◽  
Vol 7 (9) ◽  
pp. 110 ◽  
Author(s):  
Mark Castro ◽  
Christopher Moore
Keyword(s):  
Elemental Mercury ◽  
Gaseous Elemental Mercury ◽  
Mercury Fluxes
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