scholarly journals Subtropical subsidence and surface deposition of oxidized mercury produced in the free troposphere

2017 ◽  
Vol 17 (14) ◽  
pp. 8999-9017 ◽  
Author(s):  
Viral Shah ◽  
Lyatt Jaeglé
Keyword(s):  
Boundary Layer ◽  
Dry Deposition ◽  
Wet Deposition ◽  
Transport Model ◽  
Lower Troposphere ◽  
Deposition Flux ◽  
Surface Deposition ◽  
Middle Troposphere ◽  
Western Us ◽  
Wet Deposition Flux

Abstract. Oxidized mercury (Hg(II)) is chemically produced in the atmosphere by oxidation of elemental mercury and is directly emitted by anthropogenic activities. We use the GEOS-Chem global chemical transport model with gaseous oxidation driven by Br atoms to quantify how surface deposition of Hg(II) is influenced by Hg(II) production at different atmospheric heights. We tag Hg(II) chemically produced in the lower (surface–750 hPa), middle (750–400 hPa), and upper troposphere (400 hPa–tropopause), in the stratosphere, as well as directly emitted Hg(II). We evaluate our 2-year simulation (2013–2014) against observations of Hg(II) wet deposition as well as surface and free-tropospheric observations of Hg(II), finding reasonable agreement. We find that Hg(II) produced in the upper and middle troposphere constitutes 91 % of the tropospheric mass of Hg(II) and 91 % of the annual Hg(II) wet deposition flux. This large global influence from the upper and middle troposphere is the result of strong chemical production coupled with a long lifetime of Hg(II) in these regions. Annually, 77–84 % of surface-level Hg(II) over the western US, South America, South Africa, and Australia is produced in the upper and middle troposphere, whereas 26–66 % of surface Hg(II) over the eastern US, Europe, and East Asia, and South Asia is directly emitted. The influence of directly emitted Hg(II) near emission sources is likely higher but cannot be quantified by our coarse-resolution global model (2° latitude  ×  2.5° longitude). Over the oceans, 72 % of surface Hg(II) is produced in the lower troposphere because of higher Br concentrations in the marine boundary layer. The global contribution of the upper and middle troposphere to the Hg(II) dry deposition flux is 52 %. It is lower compared to the contribution to wet deposition because dry deposition of Hg(II) produced aloft requires its entrainment into the boundary layer, while rain can scavenge Hg(II) from higher altitudes more readily. We find that 55 % of the spatial variation of Hg wet deposition flux observed at the Mercury Deposition Network sites is explained by the combined variation of precipitation and Hg(II) produced in the upper and middle troposphere. Our simulation points to a large role of the dry subtropical subsidence regions. Hg(II) present in these regions accounts for 74 % of Hg(II) at 500 hPa over the continental US and more than 60 % of the surface Hg(II) over high-altitude areas of the western US. Globally, it accounts for 78 % of the tropospheric Hg(II) mass and 61 % of the total Hg(II) deposition. During the Nitrogen, Oxidants, Mercury, and Aerosol Distributions, Sources, and Sinks (NOMADSS) aircraft campaign, the contribution of Hg(II) from the dry subtropical regions was found to be 75 % when measured Hg(II) exceeded 250 pg m−3. Hg(II) produced in the upper and middle troposphere subsides in the anticyclones, where the dry conditions inhibit the loss of Hg(II). Our results highlight the importance the subtropical anticyclones as the primary conduits for the production and export of Hg(II) to the global atmosphere.

scholarly journals Surface deposition of oxidized mercury dominated by production in the upper and middle troposphere

2017 ◽  
Author(s):  
Viral Shah ◽  
Lyatt Jaeglé
Keyword(s):  
Boundary Layer ◽  
Dry Deposition ◽  
Wet Deposition ◽  
Lower Troposphere ◽  
The United States ◽  
Atmospheric Mercury ◽  
Deposition Flux ◽  
Surface Deposition ◽  
Middle Troposphere ◽  
Wet Deposition Flux

Abstract. Oxidized mercury (Hg(II)) is chemically produced in the atmosphere by oxidation of elemental mercury and is directly emitted by anthropogenic activities. We use the GEOS-Chem global chemical transport model, with gaseous oxidation driven by Br atoms, to quantify how surface deposition of Hg(II) is influenced by Hg(II) production at different atmospheric heights. We tag Hg(II) chemically produced in the lower (surface–750 hPa), middle (750–400 hPa) and upper troposphere (400 hPa–tropopause), in the stratosphere, as well as directly emitted Hg(II). A two-year simulation (2013–2014) reproduces the spatial distribution and seasonal cycle of Hg(II) surface concentrations and Hg wet deposition observed at the Atmospheric Mercury Network (AMNet) and the Mercury Deposition Network (MDN) stations over the United States to within 21 %, but displays a 46 % underestimate of wet deposition observed at the European Monitoring and Evaluation Programme (EMEP) stations. We find that Hg(II) produced in the upper and middle troposphere constitutes 91 % of the tropospheric mass of Hg(II) and 91 % of the annual Hg(II) wet deposition flux. This large global influence from the upper and middle troposphere is the result of strong chemical production coupled with a long lifetime of Hg(II) in these regions. Annually, 77–84 % of surface level Hg(II) over the western U.S., South America, South Africa, and Australia is produced in the upper and middle troposphere, whereas 26–66 % of surface Hg(II) over the eastern U.S., Europe, East Asia, and South Asia is directly emitted. Over the oceans, 72 % of surface Hg(II) is produced in the lower troposphere, because of higher Br concentrations in the marine boundary layer. The global contribution of the upper and middle troposphere to the Hg(II) dry deposition flux is 52 %. It is lower compared to the contribution to wet deposition because dry deposition of Hg(II) produced aloft requires its entrainment into the boundary layer, while rain can scavenge Hg(II) from higher altitudes more readily. We find that 55 % of the spatial variation of Hg wet deposition flux observed at the MDN sites is explained by the combined variation of precipitation and Hg(II) produced in the upper and middle troposphere. Our simulation points to a large role of Hg(II) present in the dry subtropical subsidence regions, which account for 74 % of Hg(II) at 500 hPa over the continental U.S., and more than 60 % of the surface Hg(II) over high-altitude areas of the western U.S. During the Nitrogen, Oxidants, Mercury, and Aerosol Distributions, Sources, and Sinks (NOMADSS) aircraft campaign, the contribution of these dry regions was found to be 75 % when measured Hg(II) exceeded 250 pg m−3. Our results highlight the importance of the upper and middle troposphere as key regions for Hg(II) production and of the subtropical anticyclones as the primary conduits for the production and export of Hg(II) to the global atmosphere.

scholarly journals Environmental effect of heavy metals deposition in arid city

2019 ◽  
Keyword(s):  
Heavy Metals ◽  
Dry Deposition ◽  
Arid Region ◽  
Wet Deposition ◽  
Environmental Effect ◽  
Deposition Flux ◽  
Rain Event ◽  
Heating Period ◽  
Deposition Fluxes ◽  
Wet Deposition Flux

<p>This paper analysis the contents and variation of heavy metals in wet and dry deposition in Changji (Xinjiang, China) revealed their reducing regularity for heavy metals in atmosphere in arid area. Samples (including 84 dry deposition samples and 16 wet deposition samples) were collected from January 2016 to December 2016, and the contents of heavy metals (Ni, Cu, Cd and Pb) were analyzed by AA-7000 atomic absorption spectrophotometer. The dry deposition fluxes of Ni, Cu, Cd and Pb are 3.70 mg/( m2.a), 4.81 mg/( m2. a), 0.53 mg/( m2•a) and 22.74 mg/( m2•a), respectively; the wet deposition fluxes of Ni, Cu, Cd and Pb are 0.77mg/( m2•a), 3.25mg/( m2•a), 0.04mg/( m2•a) and 0.11mg/( m2•a), respectively. Each of the four heavy metals deposition fluxes during heating period was higher than non-heating period, especially for Pb and Cd, which is mainly due to the emission of coal combustion for heating. During sampling periods, the ratio of wet deposition flux to total for Ni, Cu, Cd and Pb are 17.21%, 40.33%, 7.67% and 0.48%, respectively; the wet deposition flux is far less than dry deposition, especially for Pb. The rate of dry deposition is lower than wet deposition, however dry deposition plays an important role in scavenging heavy metals in arid region. Arid region has a low intensity and frequency of rain event, heavy metals were mainly scavenging by dry deposition attribute to its continuous and dependable process. Dry deposition has much more environmental effect on heavy metal in arid region.</p>

scholarly journals Characteristics of atmospheric mercury deposition and size-fractionated particulate mercury in urban Nanjing, China

2014 ◽  
Vol 14 (5) ◽  
pp. 2233-2244 ◽  
Author(s):  
J. Zhu ◽  
T. Wang ◽  
R. Talbot ◽  
H. Mao ◽  
X. Yang ◽  
...  
Keyword(s):  
Dry Deposition ◽  
Wet Deposition ◽  
Fine Particles ◽  
Unit Area ◽  
Atmospheric Mercury ◽  
Anthropogenic Sources ◽  
Deposition Flux ◽  
Coarse Particles ◽  
Mercury Deposition ◽  
Particulate Mercury

Abstract. A comprehensive measurement study of mercury wet deposition and size-fractionated particulate mercury (HgP) concurrent with meteorological variables was conducted from June 2011 to February 2012 to evaluate the characteristics of mercury deposition and particulate mercury in urban Nanjing, China. The volume-weighted mean (VWM) concentration of mercury in rainwater was 52.9 ng L−1 with a range of 46.3–63.6 ng L−1. The wet deposition per unit area was averaged 56.5 μg m−2 over 9 months, which was lower than that in most Chinese cities, but much higher than annual deposition in urban North America and Japan. The wet deposition flux exhibited obvious seasonal variation strongly linked with the amount of precipitation. Wet deposition in summer contributed more than 80% to the total amount. A part of contribution to wet deposition of mercury from anthropogenic sources was evidenced by the association between wet deposition and sulfates, as well as nitrates in rainwater. The ions correlated most significantly with mercury were formate, calcium, and potassium, which suggested that natural sources including vegetation and resuspended soil should be considered as an important factor to affect the wet deposition of mercury in Nanjing. The average HgP concentration was 1.10 ± 0.57 ng m−3. A distinct seasonal distribution of HgP concentrations was found to be higher in winter as a result of an increase in the PM10 concentration. Overall, more than half of the HgP existed in the particle size range less than 2.1 μm. The highest concentration of HgP in coarse particles was observed in summer, while HgP in fine particles dominated in fall and winter. The size distribution of averaged mercury content in particulates was bimodal, with two peaks in the bins of < 0.7 μm and 4.7–5.8 μm. Dry deposition per unit area of HgP was estimated to be 47.2 μg m−2 using meteorological conditions and a size-resolved particle dry deposition model. This was 16.5% less than mercury wet deposition. Compared to HgP in fine particles, HgP in coarse particles contributed more to the total dry deposition due to higher deposition velocities. Negative correlation between precipitation and the HgP concentration reflected the effect of scavenging of HgP by precipitation.

scholarly journals Impacts of Anthropogenic Emissions and Meteorological Variation on Hg Wet Deposition in Chongming, China

Atmosphere ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1301
Author(s):  
Yi Tang ◽  
Qingru Wu ◽  
Wei Gao ◽  
Shuxiao Wang ◽  
Zhijian Li ◽  
...  
Keyword(s):  
Wet Deposition ◽  
Warm Season ◽  
Meteorological Condition ◽  
Anthropogenic Emissions ◽  
Deposition Flux ◽  
Wet Deposition Flux ◽  
Meteorological Variation ◽  
Global Concern ◽  
The Impact

Mercury (Hg) is a ubiquitous environmental toxicant that has caused global concern due to its persistence and bioaccumulation in the environment. Wet deposition is a crucial Hg input for both terrestrial and aquatic environments and is a significant indicator for evaluating the effectiveness of anthropogenic Hg control. Rainwater samples were collected from May 2014 to October 2018 in Chongming Island to understand the multi-year Hg wet deposition characteristics. The annual Hg wet deposition flux ranged from 2.6 to 9.8 μg m−2 yr−1 (mean: 4.9 μg m−2 yr−1). Hg wet deposition flux in Chongming was comparable to the observations at temperate and subtropical background sites (2.0–10.2 μg m−2 yr−1) in the northern hemisphere. Hg wet deposition flux decreased from 8.6 μg m−2 yr−1 in 2014–2015 to 3.8 μg m−2 yr−1 in 2016 and was attributed to a decrease in the volume-weighted mean (VWM) Hg concentration (−4.1 ng L−1 yr−1). The reduced VWM Hg was explained by the decreasing atmospheric Hg and anthropogenic emissions reductions. The annual Hg wet deposition flux further decreased from 3.8 μg m−2 in 2016 to 2.6 μg m−2 in 2018. The reduction of warm season (April–September) rainfall amounts (356–845 mm) mainly contributed to the Hg wet deposition flux reduction during 2016–2018. The multi-year monitoring results suggest that long-term measurements are necessary when using wet deposition as an indicator to reflect the impact of anthropogenic efforts on mercury pollution control and meteorological condition variations.

scholarly journals Observed Evolution of Northward-Propagating Intraseasonal Variation over the Western Pacific: A Case Study in Boreal Early Summer

2013 ◽  
Vol 141 (2) ◽  
pp. 690-706 ◽  
Author(s):  
Masaki Katsumata ◽  
Hiroyuki Yamada ◽  
Hisayuki Kubota ◽  
Qoosaku Moteki ◽  
Ryuichi Shirooka
Keyword(s):  
Boundary Layer ◽  
Large Scale ◽  
Lower Troposphere ◽  
Western Pacific ◽  
Boreal Summer ◽  
Intraseasonal Variation ◽  
Middle Troposphere ◽  
Inactive Period ◽  
The Western Pacific

Abstract This report describes the in situ observed evolution of the atmospheric profile during an event of the boreal summer intraseasonal variation (BSISV) in the tropical western Pacific Ocean. The convectively active region of the BSISV proceeded northward over the sounding and radar network. Over the array, the situation changed from a convectively inactive period to an active period. Inspection of the sounding data revealed the gradual moistening of the lower troposphere during the convectively inactive period. The sounding-derived heat and moisture budget analyses indicated that both the convective- and large-scale processes caused moistening of the lower and middle troposphere where the radar echo tops were observed most frequently. This study is the first to identify such a “preconditioning” process for the BSISV in the western Pacific using detailed in situ observational data. During the preconditioning, an increase in CAPE was observed, as in previous studies of the MJO. An increase of moisture in the boundary layer was responsible for the increase of CAPE. The large-scale horizontal convergence in the boundary layer may be a key factor to moisten the boundary layer through the convective-scale processes, as well as through the large-scale processes to moisten the lower and middle troposphere.

scholarly journals How are NH<sub>3</sub> dry deposition estimates affected by combining the LOTOS-EUROS model with IASI-NH<sub>3</sub> satellite observations?

2018 ◽  
Author(s):  
Shelley C. van der Graaf ◽  
Enrico Dammers ◽  
Martijn Schaap ◽  
Jan Willem Erisman
Keyword(s):  
Dry Deposition ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Deposition Velocity ◽  
Deposition Flux ◽  
Deposition Fluxes ◽  
Po Valley ◽  
Atmospheric Remote Sensing ◽  
Spatial Coverage ◽  
Recent Developments

Abstract. Atmospheric levels of reactive nitrogen have substantially increased during the last century resulting in increased nitrogen deposition to ecosystems, causing harmful effects such as soil acidification, reduction in plant biodiversity and eutrophication in lakes and the ocean. Recent developments in the use of atmospheric remote sensing enabled us to resolve concentration fields of NH3 with larger spatial coverage and these observations may be used to improve the quantification of NH3 deposition. In this paper we use a relatively simple, data-driven method to derive dry deposition fluxes and surface concentrations of NH3 for Europe and for the Netherlands. The aim of this paper is to determine for the applicability and the limitations of this method for NH3 using space-born observations of the Infrared Atmospheric Sounding Interferometer (IASI) and the LOTOS-EUROS atmospheric transport model. The original modelled dry NH3 deposition flux from LOTOS-EUROS and the flux inferred from IASI are compared to indicate areas with large discrepancies between the two and where potential model improvements are needed. The largest differences in derived dry deposition fluxes occur in large parts of Central Europe, where the satellite-observed NH3 concentrations are higher than the modelled ones, and in Switzerland, northern Italy (Po Valley) and southern Turkey, where the modelled NH3 concentrations are higher than the satellite-observed ones. A sensitivity analysis of 8 model input parameters important for NH3 dry deposition modelling showed that the IASI-derived dry NH3 deposition fluxes may vary from ~ 20 % up to ~ 50 % throughout Europe. Variations in the dry deposition velocity used for NH3 led to the largest deviations in the IASI-derived dry NH3 deposition flux and should be focused on in the future. A comparison of NH3 surface concentrations with in-situ measurements of several established networks (EMEP, MAN and LML) showed no significant, or consistent improvement in the IASI-derived NH3 surface concentrations compared to the originally modelled NH3 surface concentrations from LOTOS-EUROS. It is concluded that the IASI-derived NH3 deposition fluxes do not show strong improvements compared to modelled NH3 deposition fluxes and there is future need for better, more robust, methods to derive NH3 dry deposition fluxes.

scholarly journals Composite study of aerosol export events from East Asia and North America

2012 ◽  
Vol 12 (8) ◽  
pp. 21977-22022 ◽  
Author(s):  
Y. Luan ◽  
L. Jaeglé
Keyword(s):  
Boundary Layer ◽  
North America ◽  
East Asia ◽  
Transport Model ◽  
Lower Troposphere ◽  
Temporal Variations ◽  
The Arctic ◽  
Chemical Transport Model ◽  
Mean Values ◽  
Warm Conveyor Belts

Abstract. We use satellite observations of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectrometer (MODIS) together with the GEOS-Chem global chemical transport model to contrast export of aerosols from East Asia and North America during 2004–2010. The GEOS-Chem model reproduces the spatial distribution and temporal variations of Asian aerosol outflow generally well, although a low bias (−30%) is found in the model fine mode AOD. We use the model to identify 244 aerosol pollution export events from E. Asia and 251 export events from N. America over our 7-yr study period. When these events are composited by season, we find that the AOD in the outflow is enhanced by 50–100% relative to seasonal mean values. The composite Asian plume splits into one branch going poleward towards the Arctic, with the other crossing the Pacific in 6–8 days. A fraction of the aerosols is trapped in the subtropical Pacific High. The N. American plume travels to the northeast Atlantic, reaching Europe after 4–5 days. Part of the composite plume turns anticyclonically in the Azores High, where it slowly decays. Both the Asian and N. American export events are favored by a dipole structure in sea-level pressure anomalies, associated with mid-latitude cyclone activity over the respective source regions. The observed AOD in the E. Asian outflow exhibits stronger seasonality, with a spring maximum, than the N. American outflow, with a weak summer maximum. The large spring AOD in the Asian outflow is the result of enhanced sulfate and dust aerosol concentrations, but is also due to a larger export efficiency of sulfate and SO2 from the Asian boundary layer relative to the N. American boundary layer. While the N. American sulfate outflow is mostly found in the lower troposphere (1–3 km altitude), the Asian sulfate outflow occurs at higher altitudes (2–6 km). In the Asian outflow 42–59% of the sulfate column is present above 2 km altitude, with only 24–35% in the N. American outflow. We link this to the factor of 2–5 lower precipitation in the warm conveyor belts (WCB) of midlatitude cyclones over E. Asia compared to N. America. This relative lack of precipitation makes Asian WCB very efficient for injecting aerosols in the middle troposphere.

scholarly journals Technical note: How are NH<sub>3</sub> dry deposition estimates affected by combining the LOTOS-EUROS model with IASI-NH<sub>3</sub> satellite observations?

2018 ◽  
Vol 18 (17) ◽  
pp. 13173-13196 ◽  
Author(s):  
Shelley C. van der Graaf ◽  
Enrico Dammers ◽  
Martijn Schaap ◽  
Jan Willem Erisman
Keyword(s):  
Dry Deposition ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Deposition Velocity ◽  
Monitoring And Evaluation ◽  
Technical Note ◽  
Deposition Flux ◽  
Deposition Fluxes ◽  
Po Valley ◽  
Spatial Coverage

Abstract. Atmospheric levels of reactive nitrogen have increased substantially during the last century resulting in increased nitrogen deposition to ecosystems, causing harmful effects such as soil acidification, reduction in plant biodiversity and eutrophication in lakes and the ocean. Recent developments in the use of atmospheric remote sensing enabled us to resolve concentration fields of NH3 with larger spatial coverage. These observations may be used to improve the quantification of NH3 deposition. In this paper, we use a relatively simple, data-driven method to derive dry deposition fluxes and surface concentrations of NH3 for Europe and for the Netherlands. The aim of this paper is to determine the applicability and the limitations of this method for NH3. Space-born observations of the Infrared Atmospheric Sounding Interferometer (IASI) and the LOTOS-EUROS atmospheric transport model are used. The original modelled dry NH3 deposition flux from LOTOS-EUROS and the flux inferred from IASI are compared to indicate areas with large discrepancies between the two. In these areas, potential model or emission improvements are needed. The largest differences in derived dry deposition fluxes occur in large parts of central Europe, where the satellite-observed NH3 concentrations are higher than the modelled ones, and in Switzerland, northern Italy (Po Valley) and southern Turkey, where the modelled NH3 concentrations are higher than the satellite-observed ones. A sensitivity analysis of eight model input parameters important for NH3 dry deposition modelling showed that the IASI-derived dry NH3 deposition fluxes may vary from ∼ 20 % up to ∼50 % throughout Europe. Variations in the NH3 dry deposition velocity led to the largest deviations in the IASI-derived dry NH3 deposition flux and should be focused on in the future. A comparison of NH3 surface concentrations with in situ measurements of several established networks – the European Monitoring and Evaluation Programme (EMEP), Meetnet Ammoniak in Natuurgebieden (MAN) and Landelijk Meetnet Luchtkwaliteit (LML) – showed no significant or consistent improvement in the IASI-derived NH3 surface concentrations compared to the originally modelled NH3 surface concentrations from LOTOS-EUROS. It is concluded that the IASI-derived NH3 deposition fluxes do not show strong improvements compared to modelled NH3 deposition fluxes and there is a future need for better, more robust, methods to derive NH3 dry deposition fluxes.

scholarly journals Temporal and Spatial Variations of Wet Deposition Flux of Mineral Dust in Japan

SOLA ◽  
2011 ◽  
Vol 7 ◽  
pp. 49-52 ◽  
Author(s):  
K. Osada ◽  
S. Ura ◽  
M. Kagawa ◽  
M. Mikami ◽  
T. Y. Tanaka ◽  
...  
Keyword(s):  
Wet Deposition ◽  
Mineral Dust ◽  
Spatial Variations ◽  
Deposition Flux ◽  
Temporal And Spatial Variations ◽  
Wet Deposition Flux ◽  
Temporal And Spatial

Aerosol acidity as a driver of aerosol formation and nutrient deposition to ecosystems

2020 ◽  
Author(s):  
Athanasios Nenes ◽  
Maria Kanakidou ◽  
Spyros Pandis ◽  
Armistead Russell ◽  
Shaojie Song ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Particulate Matter ◽  
Dry Deposition ◽  
Deposition Velocity ◽  
Liquid Water Content ◽  
Reactive Nitrogen ◽  
Deposition Flux ◽  
Deposition Rates ◽  
Dry Deposition Flux ◽  
Nitrate Aerosol

&lt;p&gt;Nitrogen oxides (NOx) and ammonia (NH&lt;sub&gt;3&lt;/sub&gt;) from anthropogenic and biogenic emissions are central contributors to particulate matter (PM) concentrations worldwide. Ecosystem productivity can also be strongly modulated by the atmospheric deposition of this inorganic &quot;reactive nitrogen&quot; nutrient. The response of PM and nitrogen deposition to changes in the emissions of both compounds is typically studied on a case-by-case basis, owing in part to the complex thermodynamic interactions of these aerosol precursors with other PM constituents. In the absence of rain, much of the complexity of nitrogen deposition is driven by the large difference in dry deposition velocity when a nitrogen-containing molecule is in the gas or condensed phase.&lt;/p&gt;&lt;p&gt;Here we present a simple but thermodynamically consistent approach that expresses the chemical domains of sensitivity of aerosol particulate matter to NH&lt;sub&gt;3&lt;/sub&gt; and HNO&lt;sub&gt;3&lt;/sub&gt; availability in terms of aerosol pH and liquid water content. From our analysis, four policy-relevant regimes emerge in terms of sensitivity: i) NH&lt;sub&gt;3&lt;/sub&gt;-sensitive, ii) HNO&lt;sub&gt;3&lt;/sub&gt;-sensitive, iii) combined NH&lt;sub&gt;3&lt;/sub&gt; and HNO&lt;sub&gt;3&lt;/sub&gt; sensitive, and, iv) a domain where neither NH&lt;sub&gt;3&lt;/sub&gt; and HNO&lt;sub&gt;3&lt;/sub&gt; are important for PM levels (but only nonvolatile precursors such as NVCs and sulfate). When this framework is applied to ambient measurements or predictions of PM and gaseous precursors, the &amp;#8220;chemical regime&amp;#8221; of PM sensitivity to NH3 and HNO3 availability is directly determined.&amp;#160;&lt;/p&gt;&lt;p&gt;The same framework is then extended to consider the impact of gas-to-particle partitioning, on the deposition velocity of NH&lt;sub&gt;3&lt;/sub&gt; and HNO&lt;sub&gt;3&lt;/sub&gt; individually, and combined affects the dry deposition of inorganic reactive nitrogen. Four regimes of deposition velocity emerge: i) HNO&lt;sub&gt;3&lt;/sub&gt;-fast, NH&lt;sub&gt;3&lt;/sub&gt;-slow, ii) HNO&lt;sub&gt;3&lt;/sub&gt;-slow, NH&lt;sub&gt;3&lt;/sub&gt;-fast, iii) HNO&lt;sub&gt;3&lt;/sub&gt;-fast, NH&lt;sub&gt;3&lt;/sub&gt;-fast, and, iv) HNO&lt;sub&gt;3&lt;/sub&gt;-slow, NH&lt;sub&gt;3&lt;/sub&gt;-slow. Conditions that favor strong partitioning of species to the aerosol phase strongly delay the deposition of reactive nitrogen species and promotes their accumulation in the boundary layer and potential for long-range transport.&amp;#160;&lt;/p&gt;&lt;p&gt;The use of these regimes allows novel insights and is an important tool to evaluate chemical transport models. Most notably, we find that nitric acid displays considerable variability of dry deposition flux, with maximum deposition rates found in the Eastern US (close to gas-deposition rates) and minimum rates for North Europe and China. Strong reductions in deposition velocity lead to considerable accumulation of nitrate aerosol in the boundary layer &amp;#8211;up to 10-fold increases in PM2.5 nitrate aerosol, eventually being an important contributor to high PM2.5 levels observed during haze episodes. With this new understanding, aerosol pH and associated liquid water content can be understood as control parameters that drive PM formation and dry deposition flux and arguably can catalyze the accumulation of aerosol precursors that cause intense haze events throughout the globe.&lt;/p&gt;

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