Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondônia, Brazil)

Abstract. The input of nitrogen (N) to ecosystems has increased dramatically over the past decades. While total (wet + dry) N deposition has been extensively determined in temperate regions, only very few data sets of N wet deposition exist for tropical ecosystems, and moreover, reliable experimental information about N dry deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning) season, a transition period and the onset of the wet season (clean conditions) (12 September to 14 November 2002) and were a part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign. Ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), nitrogen dioxide (NO2), nitric oxide (NO), ozone (O3), aerosol ammonium (NH4+) and aerosol nitrate (NO3-) were measured in real-time, accompanied by simultaneous meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. N dry and wet deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for N dry deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. Ignoring NH3 emission from the vegetation surface, the annual net N deposition rate is estimated to be about −11 kgN ha-1 yr-1. If on the other hand, surface-atmosphere exchange of NH3 is considered to be bi-directional, the annual net N budget at the pasture site is estimated to range from −2.15 to −4.25 kgN ha-1 yr-1.

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Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondônia, Brazil)

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-5-3131-2005 ◽

2005 ◽

Vol 5 (3) ◽

pp. 3131-3189 ◽

Cited By ~ 1

Author(s):

I. Trebs ◽

L. L. Lara ◽

L. M. M. Zeri ◽

L. V. Gatti ◽

P. Artaxo ◽

...

Keyword(s):

Biomass Burning ◽

Wet Deposition ◽

Particle Deposition ◽

Inorganic Nitrogen ◽

N Deposition ◽

Tropical Pasture ◽

Tropical Ecosystems ◽

Total N ◽

Deposition Fluxes ◽

Dry And Wet Deposition

Abstract. The input of nitrogen (N) to ecosystems has increased dramatically over the past decades. While total N deposition (wet + dry) has been extensively determined in temperate regions, only very few data sets exist about wet N deposition in tropical ecosystems, and moreover, experimental information about dry N deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning) season, a transition period and the onset of the wet season (clean conditions) (12 September to 14 November 2002, LBA-SMOCC). Ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), nitrogen dioxide (NO2), nitric oxide (NO), ozone (O3), aerosol ammonium (NH4+) and aerosol nitrate (NO3-) were measured in real-time, accompanied by simultaneous (micro-)meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. Dry and wet N deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 (re-)emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for dry N deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. We estimated a total (dry + wet) N deposition of 7.3–9.8 kgN ha-1 yr-1 to the tropical pasture site, whereof 2–4.5 kgN ha-1 yr-1 are attributed to dry N deposition and ~5.3 kgN ha-1 yr-1 to wet N deposition. Our estimate exceeds total (wet + dry) N deposition to tropical ecosystems predicted by global chemistry and transport models by at least factor of two.

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Quantifying atmospheric nitrogen deposition through a nationwide monitoring network across China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-18365-2015 ◽

2015 ◽

Vol 15 (13) ◽

pp. 18365-18405 ◽

Cited By ~ 20

Author(s):

W. Xu ◽

X. S. Luo ◽

Y. P. Pan ◽

L. Zhang ◽

A. H. Tang ◽

...

Keyword(s):

Nitrogen Deposition ◽

Wet Deposition ◽

Inorganic Nitrogen ◽

Monitoring Network ◽

Terrestrial Ecosystems ◽

N Deposition ◽

The Tibetan Plateau ◽

Deposition Fluxes ◽

Airborne Concentration ◽

The Impact

Abstract. Global reactive nitrogen (Nr) deposition to terrestrial ecosystems has increased dramatically since the industrial revolution. This is especially true in recent decades in China due to continuous economic growth. However, there are no comprehensive reports of both measured dry and wet Nr deposition across China. We therefore conducted a multiple-year study during the period mainly from 2010 to 2014 to monitor atmospheric concentrations of five major Nr species of gaseous NH3, NO2 and HNO3, and inorganic nitrogen (NH4+ and NO3−) in both particles and precipitation, based on a Nationwide Nitrogen Deposition Monitoring Network (NNDMN, covering 43 sites) in China. Wet deposition fluxes of Nr species were measured directly; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet Nr deposition. The annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet deposition fluxes (2.9–75.2 kg N ha−1 yr−1) of inorganic Nr species ranked by region as North China > Southeast China > Southwest China > Northeast China > Northwest China > the Tibetan Plateau or by land use as urban > rural > background sites, reflecting the impact of anthropogenic Nr emission. Average dry and wet N deposition fluxes were 18.5 and 19.3 kg N ha−1 yr−1, respectively, across China, with reduced N deposition dominating both dry and wet deposition. Our results suggest atmospheric dry N deposition is equally important to wet N deposition at the national scale and both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.

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Spatial-temporal patterns of inorganic nitrogen air concentrations and deposition in eastern China

10.5194/acp-2018-424 ◽

2018 ◽

Author(s):

Wen Xu ◽

Lei Liu ◽

Miaomiao Cheng ◽

Yuanhong Zhao ◽

Lin Zhang ◽

...

Keyword(s):

Land Use ◽

Seasonal Variation ◽

Dry Deposition ◽

Inorganic Nitrogen ◽

Eastern China ◽

N Deposition ◽

Organic Fertilizers ◽

Deposition Fluxes ◽

Significant Seasonal Variation ◽

Land Use Types

Abstract. Five-year (2011–2015) measurements of gaseous NH3, NO2 and HNO3 and particulate NH4+ and NO3− in air and/or precipitation were conducted at twenty-seven sites in a Nationwide Nitrogen Deposition Monitoring Network (NNDMN) to better understand spatial and temporal (seasonal and annual) characteristics of reactive nitrogen (Nr) concentrations and deposition in eastern China. Our observations reveal annual average concentrations (16.4–32.6 μg N m−3), dry deposition fluxes (15.8–31.7 kg N ha−1 yr−1) and wet/bulk deposition fluxes (18.4–28.0 kg N ha−1 yr−1) based on land use were ranked as urban > rural > background sites. Annual concentrations and dry deposition fluxes of each Nr species in air were comparable at urban and background sites in northern and southern regions, but were significantly higher at northern rural sites. These results, together with good agreement between spatial distributions of NH3 and NO2 concentrations determined from ground measurements and satellite observations, demonstrate that atmospheric Nr pollution is heavier in the northern region than in the southern region. No significant inter-annual trends were found in the annual Nr dry and wet/bulk N deposition at almost all of the selected sites. A lack of significant changes in annual averages between the 2013–2015 and 2011–2012 periods for all land use types, suggests that any effects of current emission controls are not yet apparent in Nr pollution and deposition in the region. Ambient concentrations of total Nr exhibited a non-significant seasonal variation at all land use types, although significant seasonal variations were found for individual Nr species (e.g., NH3, NO2 and pNO3−) in most cases. In contrast, dry deposition of total Nr exhibited a consistent and significant seasonal variation at all land use types, with the highest fluxes in summer and the lowest in winter. Based on sensitivity tests by the GEOS-Chem model, we found that NH3 emissions from fertilizer use (including chemical and organic fertilizers) were the largest contributor (36 %) to total inorganic Nr deposition over eastern China. Our results not only improve the understanding of spatial-temporal variations of Nr concentrations and deposition in this pollution hotspot, but also provide useful information for policy-makers that mitigation of NH3 emissions should be a priority to tackle serious N deposition in eastern China.

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Wet Inorganic Nitrogen Deposition at the Daheitin Reservoir in North China: Temporal Variation, Sources, and Biomass Burning Influences

Atmosphere ◽

10.3390/atmos11111260 ◽

2020 ◽

Vol 11 (11) ◽

pp. 1260

Author(s):

Leixiang Wu ◽

Xiaobo Liu ◽

Kun Li ◽

Wanyun Xu ◽

Wei Huang ◽

...

Keyword(s):

Nitrogen Deposition ◽

Biomass Burning ◽

Wet Deposition ◽

North China ◽

Inorganic Nitrogen ◽

Chemical Properties ◽

Northern China ◽

N Deposition ◽

Rural Site ◽

Wet Season

Atmospheric nitrogen deposition is of great concern to both air quality and the ecosystem, particularly in northern China, which covers one-quarter of China’s cultivated land and has many heavily air polluted cities. To understand the characteristics of wet N deposition at rural sites in northern China, one-year wet deposition samples were collected in the Daheitin reservoir region. Due to the intense emissions of gaseous nitrogen compounds from heating activities during cold seasons and distinct dilution effects under different rainfall intensities and frequencies, the volume weighted mean concentrations of wet N deposition showed higher levels in dry seasons but lower levels in wet seasons. In contrast, the wet N deposition rates varied consistently with precipitation, i.e., high during the wet season and lower during the dry season. The annual wet deposition rate of total inorganic ions (the sum of NO3−–N and NH4+–N) at the rural site in North China from July 2019 to June 2020 was observed at 18.9 kg N ha−1 yr−1, still remained at a relatively high level. In addition, biomass burning activities are ubiquitous in China, especially in northern China; however, studies on its impact on wet N deposition are limited. Non-sea salt potassium ion (nss-K+) was employed as a molecular tracer to investigate the characteristics of biomass burning activities as well as their impact on the chemical properties of wet N deposition. Three precipitation events with high nss-K+ levels were captured during the harvest season (June to July). The variations in the patterns of nss-K+, deposited N species, and ratios of nss-K+ to nitrogen species as well as their relationships all indicated that biomass burning emissions contributed remarkably to NO3−–N but had a minor influence on NH4+–N.

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Spatial–temporal patterns of inorganic nitrogen air concentrations and deposition in eastern China

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-10931-2018 ◽

2018 ◽

Vol 18 (15) ◽

pp. 10931-10954 ◽

Cited By ~ 30

Author(s):

Wen Xu ◽

Lei Liu ◽

Miaomiao Cheng ◽

Yuanhong Zhao ◽

Lin Zhang ◽

...

Keyword(s):

Land Use ◽

Seasonal Variation ◽

Dry Deposition ◽

Inorganic Nitrogen ◽

Eastern China ◽

N Deposition ◽

Organic Fertilizers ◽

Deposition Fluxes ◽

Significant Seasonal Variation ◽

Land Use Types

Abstract. Five-year (2011–2015) measurements of gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or precipitation were conducted at 27 sites in the Nationwide Nitrogen Deposition Monitoring Network (NNDMN) to better understand spatial and temporal (seasonal and annual) characteristics of reactive nitrogen (Nr) concentrations and deposition in eastern China. Our observations reveal annual average concentrations (16.4–32.6 µg N m−3), dry deposition fluxes (15.8–31.7 kg N ha−1 yr−1), and wet/bulk deposition fluxes (18.4–28.0 kg N ha−1 yr−1) based on land use, ranked as urban > rural > background sites. Annual concentrations and dry deposition fluxes of each Nr species in air were comparable at urban and background sites in northern and southern regions, but were significantly higher at northern rural sites. These results, together with good agreement between spatial distributions of NH3 and NO2 concentrations determined from ground measurements and satellite observations, demonstrate that atmospheric Nr pollution is heavier in the northern region than in the southern region. No significant inter-annual trends were found in the annual Nr dry and wet/bulk N deposition at almost all of the selected sites. A lack of significant changes in annual averages between the 2013–2015 and 2011–2012 periods for all land use types suggests that any effects of current emission controls are not yet apparent in Nr pollution and deposition in the region. Ambient concentrations of total Nr exhibited non-significant seasonal variation at all land use types, although significant seasonal variations were found for individual Nr species (e.g. NH3, NO2, and pNO3−) in most cases. In contrast, dry deposition of total Nr exhibited a consistent and significant seasonal variation at all land use types, with the highest fluxes in summer and the lowest in winter. Based on sensitivity tests by the GEOS-Chem model, we found that NH3 emissions from fertilizer use (including chemical and organic fertilizers) were the largest contributor (36 %) to total inorganic Nr deposition over eastern China. Our results not only improve the understanding of spatial–temporal variations of Nr concentrations and deposition in this pollution hotspot, but also provide useful information for policy-makers that mitigation of NH3 emissions should be a priority to tackle serious N deposition in eastern China.

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Wet and dry deposition of mineral dust particles in Japan: factors related to temporal variation and spatial distribution

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-21801-2013 ◽

2013 ◽

Vol 13 (8) ◽

pp. 21801-21835

Author(s):

K. Osada ◽

S. Ura ◽

M. Kagawa ◽

M. Mikami ◽

T. Y. Tanaka ◽

...

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Mineral Dust ◽

Temporal Variations ◽

Dust Particles ◽

Insoluble Residue ◽

Spatial Distributions ◽

Dust Deposition ◽

Deposition Fluxes ◽

Deposition Amount

Abstract. Data of temporal variations and spatial distributions of mineral dust deposition fluxes are very limited in terms of duration, location, and processes of deposition. To ascertain temporal variations and spatial distributions of mineral dust deposition by wet and dry processes, weekly deposition samples were obtained at Sapporo, Toyama, Nagoya, Tottori, Fukuoka, and Cape Hedo (Okinawa) in Japan during October 2008–December 2010 using automatic wet and dry separating samplers. Mineral dust weights in water-insoluble residue were estimated from Fe contents measured using an X-ray fluorescence analyzer. For wet deposition, highest and lowest annual dust fluxes were found at Toyama (9.6 g m−2 yr−1) and at Cape Hedo (1.7 g m−2 yr−1) as average values in 2009 and 2010. Higher wet deposition fluxes were observed at Toyama and Tottori, where frequent precipitation (>60% days per month) was observed during dusty seasons. For dry deposition among Toyama, Tottori, Fukuoka, and Cape Hedo, the highest and lowest annual dust fluxes were found respectively at Fukuoka (5.2 g m−2 yr−1) and at Cape Hedo (2.0 g m−2 yr−1) as average values in 2009 and 2010. Although the seasonal tendency of the monthly dry deposition amount roughly resembled that of monthly days of Kosa dust events, the monthly amount of dry deposition was not proportional to monthly days of the events. Comparison of dry deposition fluxes with vertical distribution of dust particles deduced from Lidar data and coarse particle concentrations suggested that the maximum dust layer height or thickness is an important factor for controlling the dry deposition amount after long-range transport of dust particles. Size distributions of refractory dust particles were obtained using four-stage filtration: >20, >10, >5, and >1 μm diameter. Weight fractions of the sum of >20 μm and 10–20 μm (giant fraction) were higher than 50% for most of the event samples. Irrespective of the deposition type, the giant dust fractions were decreasing generally with increasing distance from the source area, suggesting the selective depletion of larger giant particles during atmospheric transport. Because giant dust particles are an important mass fraction of dust accumulation, especially in the north Pacific where is known as a high-nutrient, low-chlorophyll (HNLC) region, the transport height of giant dust particles is an important factor for studying dust budgets in the atmosphere and their role in biogeochemical cycles.

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Plant assemblages in atmospheric deposition

10.5194/acp-2019-487 ◽

2019 ◽

Author(s):

Ke Dong ◽

Cheolwoon Woo ◽

Naomichi Yamamoto

Keyword(s):

Atmospheric Deposition ◽

Dry Deposition ◽

Wet Deposition ◽

High Throughput Sequencing ◽

Sampling Site ◽

Its2 Region ◽

Dry And Wet Deposition ◽

Custom Made ◽

Plant Assemblages ◽

Cloud Scavenging

Abstract. Plants disperse spores, pollen, and fragments into the atmosphere. The emitted plant particles return to the pedosphere by sedimentation (dry deposition) and/or by precipitation (wet deposition) and constitute part of the global cycle of substances. However, little is known regarding the taxonomic diversities and flux densities of plant particles deposited from the atmosphere. Here, plant assemblages were examined in atmospheric deposits collected in Seoul in South Korea. A custom-made automatic sampler was used to collect dry and wet deposition samples for which plant assemblages and quantities were determined using high-throughput sequencing and quantitative PCR with universal plant-specific primers targeting the internal transcribed spacer 2 (ITS2) region. Dry deposition was dominant for atmospheric deposition of plant particles (87 %). The remaining 13 % was deposited by precipitation, i.e., wet deposition, via rainout (in-cloud scavenging) and/or washout (below-cloud scavenging). Plant assemblage structures did not differ significantly between dry and wet deposition, indicating that washout, which is likely taxon-independent, predominated rainout, which is likely taxon-dependent, for wet deposition of atmospheric plant particles. A small number of plant genera were detected only in wet deposition, indicating that they might be specifically involved in precipitation through acting as nucleation sites in the atmosphere. Future interannual monitoring will control for the seasonality of atmospheric plant assemblages observed at our sampling site. Future global monitoring is also proposed to investigate geographical differences and investigate whether endemic species are involved in plant-mediated bioprecipitation in regional ecological systems.

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Atmospheric deposition and canopy interactions of nitrogen in forests

Canadian Journal of Forest Research ◽

10.1139/x93-200 ◽

1993 ◽

Vol 23 (8) ◽

pp. 1603-1616 ◽

Cited By ~ 226

Author(s):

Gary M. Lovett ◽

Steven E. Lindberg

Keyword(s):

Linear Function ◽

Dry Deposition ◽

Wet Deposition ◽

Particle Deposition ◽

Cloud Water ◽

Organic N ◽

Total System ◽

Inorganic N ◽

Deposition Rates ◽

Total Deposition

Wet deposition of nitrogen compounds was measured and dry and cloud water deposition were estimated at 11 forested sites in North America and one site in Europe. Dry deposition was a significant pathway of N input to all the forests, averaging 46% of the total deposition. At most of these sites, NH4+ was the dominant form of fixed N in the air, but HNO3 vapor dominated the dry deposition of N. Coarse-particle deposition was often important, but fine-particle deposition usually contributed only a small amount of the dry-deposited N. The deposition rates of inorganic N, which ranged between 4.8 and 27 kg N•ha−1•year−1, were generally much higher than has been reported by other studies measuring only wet or bulk deposition. The highest deposition rates were at the high-elevation sites in the southeastern and northeastern United States and much of the deposition at these sites was attributed to cloud water. Throughfall and stemflow (TF + SF) flux was also measured at all sites, and the net canopy exchange (NCE = (TF + SF)–total deposition) was found to be negative (indicating consumption of N in the canopy) for NH4+ and NO3−, and positive (indicating canopy release) for organic N. Past reports of canopy release of NO3− can probably be attributed to washoff of dry-deposited NO3− species. Consumption of inorganic N in the canopy ranged from 1 to 12 kg N•ha−1•year−1, and was highest in the spruce and spruce–fir stands. When organic N was included in the canopy N balance, the net canopy uptake of N was generally < 15% of the total system N requirement. Total N deposition was a linear function of wet deposition for low-elevation sites, and dry deposition was a linear function of the net throughfall flux for NO3−.

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Elemental carbon in snow at Changbai Mountain, northeastern China: concentrations, scavenging ratios, and dry deposition velocities

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-629-2014 ◽

2014 ◽

Vol 14 (2) ◽

pp. 629-640 ◽

Cited By ~ 14

Author(s):

Z. W. Wang ◽

J. C. Gallet ◽

C. A. Pedersen ◽

X. S. Zhang ◽

J. Ström ◽

...

Keyword(s):

Dry Deposition ◽

Wet Deposition ◽

Radiative Forcing ◽

Elemental Carbon ◽

Northeastern China ◽

Snow Surface ◽

Deposition Fluxes ◽

The Mean ◽

Deposition Processes ◽

Scavenging Ratio

Abstract. Light-absorbing aerosol – particularly elemental carbon (EC) – while mixed with snow and ice is an important climate driver from the enhanced absorption of solar radiation. Currently, considerable efforts are being made to estimate its radiative forcing on a global scale, but several uncertainties remain, particularly those regarding its deposition processes. In this study, concurrent measurements of EC in air and snow are performed for three years (2009–2012) at Changbai station, northeastern China. The scavenging ratio and the wet- and dry-deposition fluxes of EC over the snow surface are estimated. The mean EC concentration in the surface snow is 1000 ± 1500 ng g−1, ranging from 7 to 7640 ng g−1. The mean value of the scavenging ratio of EC by snow is 140 ± 100, with a median value of 150, which is smaller than that reported in Arctic areas. A non-rimed snow process is a significant factor in interpreting differences with Arctic areas. Wet-deposition fluxes of EC are estimated to be 0.47 ± 0.37 μg cm−2 month−1 on average over the three snow seasons studied. Dry deposition is more than five times higher, with an average of 2.65 ± 1.93 μg cm−2 month−1; however, only winter period estimation is possible (December–February). During winter in Changbai, 87% of EC in snow is estimated to be due to dry deposition, with a mean dry deposition velocity of 6.44 × 10−3 m s−1 and median of 8.14 × 10−3 m s−1. Finally, the calculation of the radiative effect shows that 500 ng g−1 of dry-deposited EC to a snow surface absorbs three times more incoming solar energy than the same mass mixed in the snow through wet deposition. Deposition processes of an EC-containing snow surface are, therefore, crucial to estimate its radiative forcing better, particularly in northeastern China, where local emission strongly influences the level and gradient of EC in the snowpack, and snow-covered areas are cold and dry due to the atmospheric general circulation. Furthermore, this study builds on the knowledge to characterize the conditions in the snow-laden Chinese rural areas better as well as to constrain transport of EC to the Arctic better.

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