Total gaseous mercury in Pearl River Delta region, China during 2008 winter period

Zheng, Li; Xia, Chonghuan; Wang, Xinming; Xiang, Yunrong; Xie, Zhouqing

doi:10.1016/j.atmosenv.2010.11.032

Cited by 37 publications

(24 citation statements)

References 25 publications

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“…This is consistent with many other urban cases, which report a similar pattern with the daily peak in the morning and decrease in the afternoon (e.g. Friedli et al, 2011;Song et al, 2009;Liu et al, 2011;Li et al, 2011;Mao et al, 2008). However, quite different diurnal patterns were observed at many suburban sites with the daily maximum occurring at 12 p.m.-3 p.m. probably owing to local emissions and transport(e.g.…”

Section: Diurnal Variationsupporting

confidence: 77%

Characteristics of atmospheric Total Gaseous Mercury (TGM) observed in urban Nanjing, China

et al. 2012

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Abstract. Long-term continuous measurements of total gaseous mercury (TGM=gaseous elemental mercury (GEM)+ reactive gaseous mercury (RGM)) were conducted simultaneously along with meteorological variables and a suite of trace gases at an urban site in Nanjing, China from 18 January to 31 December 2011. Measurements were conducted using a high resolution mercury vapor analyzer (Tekran 2537B) with 5-min time resolution. The average concentration of TGM was 7.9 ± 7.0 ng m −3 with a range of 0.8-180 ng m −3 over the study period. TGM concentrations followed a typical lognormal pattern dominated by a range of 3-7 ng m −3 , which was significantly higher than the continental background values (∼1.5 ng m −3 ) in Northern Hemisphere. The mean seasonal TGM concentrations decreased in the following order: summer, spring, fall, and winter. This seasonal pattern was quite different from measurements at most other sites around the world. We attributed high monthly average concentrations to the re-volatilization of deposited mercury during the warm season due to high temperatures and greater solar radiation. Previous modeling studies suggested that Nanjing and the surrounding region have the largest Chinese natural emissions during the summer. Positive correlations between temperature, solar radiation, and TGM concentration combined with no correlation between CO and TGM in summer provide a strong indication that natural sources are important in Nanjing while most sharp peaks were caused by anthropogenic sources. TGM concentrations in Nanjing exhibited a noticeable diurnal pattern with a sharp increase after sunrise and peak of greater than 8 ng m −3 during 7-10 a.m. local time. Further, seasonally averaged diurnal cycles of TGM exhibited considerably different patterns with the largest variation in spring and insignificant fluctuations in winter. Using HYSPLIT backwards trajectories from six clusters, it was indicated that the highest TGM concentrations, 11.9 ng m −3 , was derived from local air masses. The cleanest air masses, with an average TGM concentration of 4.7 and 5.9 ng m −3 , were advected from the north via fast transport facilitated by sweeping synoptic flows.

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Section: Diurnal Variationsupporting

confidence: 77%

Characteristics of atmospheric Total Gaseous Mercury (TGM) observed in urban Nanjing, China

et al. 2012

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“…Han et al (2004) attributed a negative correlation between total gaseous mercury (TGM) and temperature to seasonal difference in emission rates of coal-fired power plants (winter maximum) in the northern hemisphere based on two summers of measurement data. A negative correlation between temperature and TGM was shown by measurements during a winter month at a rural site in the central Pearl River Delta region (Li et al, 2011). A ten month data set at Elora, Ontario, Canada suggested highest Hg 0 concentrations in late spring and fall possibly due to increases in air temperature among other factors in spring and lower atmospheric mixing height in fall (Baya and Van Heyst, 2010).…”

Section: H Mao Et Al: Speciated Mercury At Marine Coastal and Inlmentioning

confidence: 99%

Speciated mercury at marine, coastal, and inland sites in New England – Part 2: Relationships with atmospheric physical parameters

et al. 2012

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Abstract. Long-term continuous measurements of gaseous elemental mercury (Hg 0 ), reactive gaseous mercury (RGM), and particulate phase mercury (Hg P ) were conducted at coastal (Thompson Farm, denoted as TF), marine (Appledore Island, denoted as AI), and elevated inland rural (Pac Monadnock, denoted as PM) monitoring sites of the AIRMAP Observing Network. Diurnal, seasonal, annual, and interannual variability in Hg 0 , RGM, and Hg P from the three distinctly different environments were characterized and compared in Part 1. Here in Part 2 relationships between speciated mercury (i.e., Hg 0 , RGM, and Hg P ) and climate variables (e.g., temperature, wind speed, humidity, solar radiation, and precipitation) were examined. The best point-to-point correlations were found between Hg 0 and temperature in summer at TF and spring at PM, but there was no similar correlation at AI. Subsets of data demonstrated regional impacts of episodic dynamic processes such as strong cyclonic systems on ambient levels of Hg 0 at all three sites, possibly through enhanced oceanic evasion of Hg 0 . A tendency of higher levels of RGM and Hg P was identified in spring and summer under sunny conditions in all environments. Specifically, the 10th, 25th, median, 75th, and 90th percentile mixing ratios of RGM and Hg P increased with stronger solar radiation at both the coastal and marine sites. These metrics decreased with increasing wind speed at AI indicating enhanced loss of RGM and Hg P through deposition. RGM and Hg P levels correlated with temperature positively in spring, summer and fall at the coastal and marine locations. At the coastal site relationships between RGM and relative humidity suggested a clear decreasing tendency in all metrics from <40 % to 100 % relative humidity in all seasons especially in spring, compared to less variability in the marine environment. The effect of precipitation on RGM at coastal and marine locations was similar. At the coastal site, RGM levels were a factor of 3-4 to two orders of magnitude higher under dry conditions than rainy conditions in all seasons. In winter RGM mixing ratios appeared to be mostly above the limit of detection (LOD) during snowfalls suggesting less scavenging efficiency of snow. Mixing ratios of Hg P at the coastal and marine sites remained above the LOD under rainy conditions. Precipitation had negligible impact on the magnitude and pattern of diurnal variation of Hg P in all seasons in the marine environment.

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“…During the nighttime, TGM is relatively stable especially in autumn. We can see the same peak at about 8:00 in the morning in other coastal sites in China (Chenshantou and Wanqingsha) (Ci et al, 2011a;Li et al, 2011). At Chongming and Chenshantou, much sharper increase occurs at 5:00 in summer and autumn.…”

Section: Diurnal Variation Of Speciated Hg Concentrationsmentioning

confidence: 52%

“…The median value being smaller than the mean indicates that TGM is in a relatively low level near the background. The average TGM at Chongming site was 1.8-2 times the Northern Hemisphere background (Slemr et al, 2011), close to those at other coastal sites in China (2.3 ng m -3 at Chengshantou site in the Yellow Sea region and 2.9 ng m -3 at Wanqingsha site in the South China Sea region) (Ci et al, 2011a;Li et al, 2011 ) (Fu et al, 2008) and Miyun (8.9 pg m -3 ) (Zhang et al, 2013). PHg ranges from 0.1 to 315.9 pg m -3 with an average of 21.5 ± 25.4 pg m -3 , quite close to the level at the remote site Mt.…”

Section: Characteristics Of Speciated Hg Concentrations Overall Statimentioning

confidence: 83%

“…Nguyen et al (2010) reported the average TGM in Jeju, Korea during 2006-2007 to be 3.9 ng m -3 . Two coastal sites in China are Chengshantou in the Yellow Sea region and Wanqingsha in the South China Sea region, where the average TGM concentrations were found to be 2.3 and 2.9 ng m -3 , respectively (Ci et al, 2011a;Li et al, 2011). Corresponding monitoring campaigns at two offshore marine sites in the Yellow Sea and South China Sea regions showed an average TGM level of 2.6 ng m -3 (Fu et al, 2010b;Ci et al, 2011b).…”

Section: Introductionmentioning

confidence: 99%

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Characteristics and Sources of Speciated Atmospheric Mercury at a Coastal Site in the East China Sea Region

Zhang

Wang

et al. 2017

Aerosol Air Qual. Res.

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Atmospheric mercury is a global concern due to its ability of long-range transport. In order to understand the characteristics and sources of speciated mercury in the East China Sea region, a coastal monitoring site was established on Chongming Island in Shanghai, China. Total gaseous mercury (TGM), reactive gaseous mercury (RGM) and particulatebound mercury ( , respectively. TGM has a sharp increase at 5:00 in the morning and reaches peak at about 8:00, which is probably caused by the downward mixing of enhanced TGM aloft originated from regional sources. Wind roses suggest that urban Shanghai area has a considerable contribution to TGM in Chongming. Repartitioning of reactive mercury from particles to the air under the influence of air temperature could be one major source of RGM. Four heavy mercury pollution episodes were selected for source analysis. Mercury pollution in the summer event is mainly from the southwest direction with high ∆TGM/∆CO ratio and has the most influence on the North China Plain (NCP) region. The winter event is mainly under the influence of industrial pollution from the NCP region. The autumn event is contributed by both industrial pollution and biomass burning in North and Northeast China exhibiting a lower slope of ∆PHg/∆TGM. Springtime Asian long-range transport (ALRT) is crucial to the mercury background of North America. However, in the spring event identified in this study the mercury outflow from low altitude through East China mostly ascended to high altitude during the transpacific airmass transport. This provides an important incentive for future studies to focus on the way of mercury outflow from East Asia.

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Total gaseous mercury in Pearl River Delta region, China during 2008 winter period

Cited by 37 publications

References 25 publications

Characteristics of atmospheric Total Gaseous Mercury (TGM) observed in urban Nanjing, China

Characteristics of atmospheric Total Gaseous Mercury (TGM) observed in urban Nanjing, China

Speciated mercury at marine, coastal, and inland sites in New England – Part 2: Relationships with atmospheric physical parameters

Characteristics and Sources of Speciated Atmospheric Mercury at a Coastal Site in the East China Sea Region

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