Mercury Wet Deposition and Speciated Air Concentrations from Two Urban Sites in New York State: Temporal Patterns and Regional Context

Abstract

Since 2008, ambient speciated mercury (Hg) concentrations and weekly Hg wet deposition have been measured at two urban locations in New York -Rochester and New York City (borough of Bronx). These measurements were initiated to establish ambient Hg baselines ahead of anticipated emissions reductions, as well as characterize air concentrations and deposition at two different urban settings. In this paper seasonal and regional patterns in Hg wet deposition are presented, as well as seasonal, day of week and diurnal patterns in ambient Hg species at these two sites. The mean (and median) Hg concentration in precipitation was 9.56 ng/L (8.37 ng/L) at the Bronx site, and 9.95 ng/L (8.30 ng/L) at Rochester. Mean ambient air concentrations of gaseous elemental Hg (GEM), reactive gaseous Hg (RGM), and particle-bound Hg (PBM) at the Bronx and Rochester sites were 1.52 and 1.40 ng/m 3 , 6.26 and 8.24 pg/m 3 , and 7.96 and 13.48 pg/m 3 , respectively. Conditional probability function analysis was used to examine potential source regions impacting these two sites. Using these data we were able to examine monthly and diurnal patterns in speciated ambient Hg; however, more research is needed to more fully characterize potential emission sources that impact these sites.

Impacts of large-scale circulation on urban ambient concentrations of gaseous elemental mercury in New York, USA

“…2, Table 1), in agreement with previous urban site studies (Denis et al, 2006;Liu et al, 2007;Zhu et al, 2012;Zhang et al, 2013;Civerolo et al, 2014). The pattern of such annual cycles was evidenced in > 20 % (< 10 %) of the warm (cold) season in 2009 and 2010 and 67 % (31 %) of the warm (cold) season in 2014 experiencing larger GEM mixing ratios (Table 1).…”

“…The Tekran system was operated according to standard operating procedures from the NADP's AMNet. The AMNet site liaison performs annual site visits, which include manual injections to verify the internal permeation source, and is responsible for quality assurance of the data (Civerolo et al, 2014). Additional details can be found in Landis et al (2002) and Gay et al (2013).…”

“…Urban concentrations of GEM/TGM in the US varied between 0.05 and 324 ng m −3 (5.6-36 288 ppqv) (Mao et al, 2016). In comparison, urban concentrations and their temporal variability were larger than rural, remote, and high-elevation concentrations in the Northern Hemisphere (e.g., Kim and Kim, 2001;Feng et al, 2003;Denis et al, 2006;Liu et al, 2007;Peterson et al, 2009;Sprovieri et al, 2010;Zhu et al, 2012;Lan et al, 2012Lan et al, , 2014Chen et al, 2013;Civerolo et al, 2014;Fu et al, 2015;Brown et al, 2015;Mao et al, 2016, and references therein) owing to numerous controlling factors, including anthropogenic and legacy emissions, deposition, meteorology, transport, and atmospheric chemistry (Mao et al, 2016).…”

Impacts of Large-Scale Circulation on Urban Ambient Concentrations of Gaseous Elemental Mercury in New York, USA

“…3.1 General characteristics of diurnal, seasonal, and interannual variation Annual cycles of 2009, 2010, and 2014 displayed larger GEM mixing ratios (> the 75th percentile value of the entire study) during the warm seasons (summer-spring) than the cool seasons (fall-winter) (Fig. 2, Table 1), in agreement with previous urban site studies (Denis et al, 2006;Liu et al, 2007;Zhu et al, 2012;Zhang et al, 2013;Civerolo et al, 2014). The pattern of such annual cycles was evidenced in > 20 % (< 10 %) of the warm (cold) season in 2009 and 2010 and 67 % (31 %) of the warm (cold) season in 2014 experiencing larger GEM mixing ratios (Table 1).…”

“…Urban concentrations of GEM/TGM in the US varied between 0.05 and 324 ng m −3 (5.6-36 288 ppqv) (Mao et al, 2016). In comparison, urban concentrations and their temporal variability were larger than rural, remote, and high-elevation concentrations in the Northern Hemisphere H. Mao et al: Impacts of large-scale circulation on urban ambient concentrations (e.g., Kim and Kim, 2001;Feng et al, 2003;Denis et al, 2006;Liu et al, 2007;Peterson et al, 2009;Sprovieri et al, 2010;Zhu et al, 2012;Lan et al, 2012Lan et al, , 2014Chen et al, 2013;Civerolo et al, 2014;Fu et al, 2015;Brown et al, 2015;Mao et al, 2016, and references therein) owing to numerous controlling factors, including anthropogenic and legacy emissions, deposition, meteorology, transport, and atmospheric chemistry (Mao et al, 2016).…”