Modelling nitrogen deposition: dry deposition velocities on various land-use types in Switzerland

Abstract. Reactive nitrogen (N) emissions have increased over the last 150 years as a result of greater fossil fuel combustion and food production. The resulting increase in N deposition can alter the function of ecosystems, but characterizing its ecological impacts remains challenging, in part because of uncertainties in model-based estimates of N dry deposition. Here, we use the Geophysical Fluid Dynamics Laboratory (GFDL) atmospheric chemistry–climate model (AM3) coupled with the GFDL land model (LM3) to estimate dry deposition velocities. We leverage the tiled structure of LM3 to represent the impact of physical, hydrological, and ecological heterogeneities on the surface removal of chemical tracers. We show that this framework can be used to estimate N deposition at more ecologically relevant scales (e.g., natural vegetation, water bodies) than from the coarse-resolution global model AM3. Focusing on North America, we show that the faster removal of N over forested ecosystems relative to cropland and pasture implies that coarse-resolution estimates of N deposition from global models systematically underestimate N deposition to natural vegetation by 10 % to 30 % in the central and eastern US. Neglecting the sub-grid scale heterogeneity of dry deposition velocities also results in an underestimate (overestimate) of the amount of reduced (oxidized) nitrogen deposited to water bodies. Overall, changes in land cover associated with human activities are found to slow down the removal of N from the atmosphere, causing a reduction in the dry oxidized, dry reduced, and total (wet+dry) N deposition over the contiguous US of 8 %, 26 %, and 6 %, respectively. We also find that the reduction in the overall rate of removal of N associated with land-use change tends to increase N deposition on the remaining natural vegetation and facilitate N export to Canada. We show that sub-grid scale differences in the surface removal of oxidized and reduced nitrogen imply that projected near-term (2010–2050) changes in oxidized (−47 %) and reduced (+40 %) US N emissions will cause opposite changes in N deposition to water bodies (increase) and natural vegetation (decrease) in the eastern US, with potential implications for acidification and ecosystems.

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Comparison of nitrogen deposition across different land use types in agro-pastoral catchments of western China and Mongolia

Atmospheric Environment ◽

10.1016/j.atmosenv.2018.11.021 ◽

2019 ◽

Vol 199 ◽

pp. 313-322 ◽

Cited By ~ 3

Author(s):

Jinling Lv ◽

Andreas Buerkert ◽

Katherine B. Benedict ◽

Guojun Liu ◽

Chaoyan Lv ◽

...

Keyword(s):

Land Use ◽

Nitrogen Deposition ◽

Western China ◽

Land Use Types

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Representing sub-grid scale variations in nitrogen deposition associated with land use in a global Earth System Model: implications for present and future nitrogen deposition fluxes over North America

10.5194/acp-2018-572 ◽

2018 ◽

Author(s):

Fabien Paulot ◽

Sergey Malyshev ◽

Tran Nguyen ◽

John D. Crounse ◽

Elena Shevliakova ◽

...

Keyword(s):

Land Use ◽

North America ◽

Nitrogen Deposition ◽

Dry Deposition ◽

N Deposition ◽

Natural Vegetation ◽

Water Bodies ◽

System Model ◽

Earth System ◽

Subgrid Scale

Abstract. Reactive nitrogen (N) emissions have increased over the last 150 years as a result of greater fossil fuel combustion and food production. The resulting increase in N deposition can alter the function of ecosystems, but characterizing its ecological impacts remains challenging, in part because of uncertainties in model-based estimates of N dry deposition. Here, we leverage the tiled structure of the land component (LM3) of the Geophysical Fluid Dynamics Laboratory (GFDL) Earth System Model to represent the impact of physical, hydrological, and ecological heterogeneities on the surface removal of chemical tracers. We show that this framework can be used to estimate N deposition at more ecologically-relevant scales (e.g., natural vegetation, water bodies) than from the coarse-resolution global chemistry–climate model (GFDL-AM3). Focusing on North America, we show that the faster removal of N over forested ecosystems relative to cropland and pasture implies that coarse resolution estimates of N deposition from global models systematically underestimate N deposition to natural vegetation by 10 to 30 % in the Central and Eastern US. Neglecting the subgrid scale heterogeneity of dry deposition velocities also results in an underestimate (overestimate) of the amount of reduced (oxidized) nitrogen deposited to water bodies. Overall, changes in land cover associated with human activities are found to slow down the removal of N from the atmosphere, causing a reduction in the dry oxidized, dry reduced, and total N deposition over the contiguous US of 8 %, 26 %, and 6 %, respectively. We also find that the reduction in the overall rate of removal of N associated with land-use change tends to increase N deposition on the remaining natural vegetation and facilitate N export to Canada. We show that subgrid scale differences in the surface removal of oxidized and reduced nitrogen imply that near-term (2010–2050) changes in oxidized (−47 %) and reduced (+40 %) US N emissions will cause opposite changes in N deposition to water bodies (increase) and natural vegetation (decrease) in the Eastern US, with potential implications for acidification and ecosystems.

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Responses of surface ozone air quality to anthropogenic nitrogen deposition in the Northern Hemisphere

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-9781-2017 ◽

2017 ◽

Vol 17 (16) ◽

pp. 9781-9796 ◽

Cited By ~ 7

Author(s):

Yuanhong Zhao ◽

Lin Zhang ◽

Amos P. K. Tai ◽

Youfan Chen ◽

Yuepeng Pan

Keyword(s):

Land Use ◽

Air Quality ◽

Nitrogen Deposition ◽

Northern Hemisphere ◽

Dry Deposition ◽

Surface Ozone ◽

Land Use Changes ◽

Nox Emissions ◽

Anthropogenic Nitrogen ◽

Anthropogenic Nitrogen Deposition

Abstract. Human activities have substantially increased atmospheric deposition of reactive nitrogen to the Earth's surface, inducing unintentional effects on ecosystems with complex environmental and climate consequences. One consequence remaining unexplored is how surface air quality might respond to the enhanced nitrogen deposition through surface–atmosphere exchange. Here we combine a chemical transport model (GEOS-Chem) and a global land model (Community Land Model, CLM) to address this issue with a focus on ozone pollution in the Northern Hemisphere. We consider three processes that are important for surface ozone and can be perturbed by the addition of atmospheric deposited nitrogen – namely, emissions of biogenic volatile organic compounds (VOCs), ozone dry deposition, and soil nitrogen oxide (NOx) emissions. We find that present-day anthropogenic nitrogen deposition (65 Tg N a−1 to the land), through enhancing plant growth (represented as increases in vegetation leaf area index, LAI, in the model), could increase surface ozone from increased biogenic VOC emissions (e.g., a 6.6 Tg increase in isoprene emission), but it could also decrease ozone due to higher ozone dry deposition velocities (up to 0.02–0.04 cm s−1 increases). Meanwhile, deposited anthropogenic nitrogen to soil enhances soil NOx emissions. The overall effect on summer mean surface ozone concentrations shows general increases over the globe (up to 1.5–2.3 ppbv over the western US and South Asia), except for some regions with high anthropogenic NOx emissions (0.5–1.0 ppbv decreases over the eastern US, western Europe, and North China). We compare the surface ozone changes with those driven by the past 20-year climate and historical land use changes. We find that the impacts from anthropogenic nitrogen deposition can be comparable to the climate- and land-use-driven surface ozone changes at regional scales and partly offset the surface ozone reductions due to land use changes reported in previous studies. Our study emphasizes the complexity of biosphere–atmosphere interactions, which can have important implications for future air quality prediction.

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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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Responses of surface ozone air quality to anthropogenic nitrogen deposition in the Northern Hemisphere

10.5194/acp-2017-242 ◽

2017 ◽

Author(s):

Yuanhong Zhao ◽

Lin Zhang ◽

Amos P. K. Tai ◽

Youfan Chen ◽

Yuepeng Pan

Keyword(s):

Land Use ◽

Air Quality ◽

Nitrogen Deposition ◽

Northern Hemisphere ◽

Dry Deposition ◽

Surface Ozone ◽

Land Use Changes ◽

Nox Emissions ◽

Anthropogenic Nitrogen ◽

Anthropogenic Nitrogen Deposition

Abstract. Human activities have substantially increased atmospheric deposition of reactive nitrogen to the Earth’s surface, inducing unintentional effects on ecosystems with complex environmental and climate consequences. One consequence remaining unexplored is how surface air quality might respond to the enhanced nitrogen deposition through surface-atmosphere exchange. Here we combine a chemical transport model (GEOS-Chem) and a global land model (Community Land Model) to address this issue with a focus on ozone pollution in the Northern Hemisphere. We consider three processes that are important for surface ozone and can be perturbed by addition of atmospheric deposited nitrogen, namely, emissions of biogenic volatile organic compounds (VOCs), ozone dry deposition, and soil nitrogen oxide (NOx) emissions. We find that present-day anthropogenic nitrogen deposition (65 Tg N a−1 to the land), through enhancing plant growth (represented as increases in vegetation leaf area index (LAI) in the model), could increase surface ozone from increased biogenic VOC emissions (e.g., a 6.6 Tg increase in isoprene emission), but could also decrease ozone due to higher ozone dry deposition velocities (up to 0.02–0.04 cm s−1 increases). Meanwhile, deposited anthropogenic nitrogen to soil enhances soil NOx emissions. The overall effect on summer mean surface ozone concentrations show general increases over the globe (up to 1.5–2.3 ppbv over the western US and South Asia), except for some regions with high anthropogenic NOx emissions (0.5–1.0 ppbv decreases over the eastern US, Western Europe, and North China). We compare the surface ozone changes with those driven by the past 20-year climate and historical land use changes. We find that the impacts from anthropogenic nitrogen deposition can be comparable to the climate and land use driven surface ozone changes at regional scales, and partly offset the surface ozone reductions due to land use changes reported in previous studies. Our study emphasizes the complexity of biosphere-atmosphere interactions, which can have important implications for future air quality prediction.

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Atmospheric dry and wet nitrogen deposition on three contrasting land use types of an agricultural catchment in subtropical central China

Atmospheric Environment ◽

10.1016/j.atmosenv.2012.10.068 ◽

2013 ◽

Vol 67 ◽

pp. 415-424 ◽

Cited By ~ 59

Author(s):

Jianlin Shen ◽

Yong Li ◽

Xuejun Liu ◽

Xiaosheng Luo ◽

Hong Tang ◽

...

Keyword(s):

Land Use ◽

Nitrogen Deposition ◽

Central China ◽

Land Use Types

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Particle dry deposition algorithms in CMAQ version 5.3: characterization of critical parameters and land use dependence using DepoBoxTool version 1.0

10.5194/gmd-2021-129 ◽

2021 ◽

Author(s):

Qian Shu ◽

Benjamin Murphy ◽

Jonathan E. Pleim ◽

Donna Schwede ◽

Barron H. Henderson ◽

...

Keyword(s):

Land Use ◽

Particle Size ◽

Air Quality ◽

Dry Deposition ◽

Box Model ◽

Critical Parameters ◽

Average Particle ◽

Area Index ◽

Deposition Velocities ◽

Use Categories

Abstract. This study investigates particle dry deposition by characterizing critical parameters and land-use dependence in a 0-D box model as well as quantifying the resulting impact of dry deposition parameterizations on regional-scale 3-D model predictions. A publicly available box model configured with several land-use dependent dry deposition schemes is developed to evaluate predictions of several model approaches with available measurements. The 0-D box model results suggest that current dry deposition schemes in 3-D regional models underestimate particle dry deposition velocities, but this varies with size distribution properties and land-use categories. We propose two revised schemes to improve dry deposition performance in air quality models and test them in the Community Multiscale Air Quality (CMAQ) model. The first scheme improves the previous CMAQ scheme by preserving the original dry deposition impaction calculation but turning off redundant integration across particle size for each aerosol mode. The second scheme adds a dependence on leaf area index (LAI) to better estimate uptake to vegetative surfaces while using a settling velocity that is integrated across particle size for the Stokes number calculation. CMAQ model performance was evaluated for a month in July 2011 for the conterminous U.S. based on available observations of ambient sulfate (SO4) aerosol concentrations from multiple routine particulate matter monitoring networks. Incorporation of the first scheme has a larger impact on coarse particles than fine particles, systematically reducing monthly domain-wide average particle dry deposition velocities (Vd) by approximately 96% and 35%, respectively, and increasing monthly average SO4 concentrations by 395% and 21%. After incorporating LAI into the boundary layer resistance (Rb), the second scheme creates more spatial diversity of Vd and changes SO4 concentrations (coarse = −76% to +336%; fine = −7% to +18%) with land-use categories. These modifications are incorporated into the current publicly available version of CMAQ (v5.3 and beyond).

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