Simulating the impact of volatilization on atmospheric concentrations of pesticides with the 3D chemistry-transport model CHIMERE: method development and application to S-metolachlor and folpet

Abstract. The distribution and budget of oxygenated organic compounds in the atmosphere and their impact on tropospheric chemistry are still poorly constrained. Near-global space-borne measurements of seasonally resolved upper tropospheric profiles of methanol (CH3OH) by the ACE Fourier transform spectrometer provide a unique opportunity to evaluate our understanding of this important oxygenated organic species. ACE-FTS observations from March 2004 to August 2005 period are presented. These observations reveal the pervasive imprint of surface sources on upper tropospheric methanol: mixing ratios observed in the mid and high latitudes of the Northern Hemisphere reflect the seasonal cycle of the biogenic emissions whereas the methanol cycle observed in the southern tropics is highly influenced by biomass burning emissions. The comparison with distributions simulated by the state-of-the-art global chemistry transport model, LMDz-INCA, suggests that: (i) the background methanol (high southern latitudes) is correctly represented by the model considering the measurement uncertainties; (ii) the current emissions from the continental biosphere are underestimated during spring and summer in the Northern Hemisphere leading to an underestimation of modelled upper tropospheric methanol; (iii) the seasonal variation of upper tropospheric methanol is shifted to the fall in the model suggesting either an insufficient destruction of CH3OH (due to too weak chemistry and/or deposition) in fall and winter months or an unfaithful representation of transport; (iv) the impact of tropical biomass burning emissions on upper tropospheric methanol is rather well reproduced by the model. This study illustrates the potential of these first global profile observations of oxygenated compounds in the upper troposphere to improve our understanding of their global distribution, fate and budget.

Download Full-text

The impact of shipping emissions on air pollution in the greater North Sea region – Part 2: Scenarios for 2030

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-759-2016 ◽

2016 ◽

Vol 16 (2) ◽

pp. 759-776 ◽

Cited By ~ 17

Author(s):

V. Matthias ◽

A. Aulinger ◽

A. Backes ◽

J. Bieser ◽

B. Geyer ◽

...

Keyword(s):

North Sea ◽

Transport Model ◽

So2 Emissions ◽

Chemistry Transport Model ◽

The North ◽

International Regulations ◽

The North Sea ◽

Sea Area ◽

The Impact ◽

Ship Fuels

Abstract. Scenarios for future shipping emissions in the North Sea have been developed in the framework of the Clean North Sea Shipping project. The effects of changing NOx and SO2 emissions were investigated with the CMAQ chemistry transport model for the year 2030 in the North Sea area. It has been found that, compared to today, the contribution of shipping to the NO2 and O3 concentrations will increase due to the expected enhanced traffic by more than 20 and 5 %, respectively, by 2030 if no regulation for further emission reductions is implemented in the North Sea area. PM2.5 will decrease slightly because the sulfur contents in ship fuels will be reduced as international regulations foresee. The effects differ largely between regions, seasons and date of the implementation of stricter regulations for NOx emissions from newly built ships.

Download Full-text

Towards a representation of halogen chemistry within volcanic plumes in a chemistry transport model

Geoscientific Model Development Discussions ◽

10.5194/gmdd-7-2581-2014 ◽

2014 ◽

Vol 7 (2) ◽

pp. 2581-2650 ◽

Cited By ~ 4

Author(s):

L. Grellier ◽

V. Marécal ◽

B. Josse ◽

P. D. Hamer ◽

T. J. Roberts ◽

...

Keyword(s):

Transport Model ◽

Computational Cost ◽

Ambient Air ◽

Heterogeneous Reactions ◽

Tropospheric Chemistry ◽

Volcanic Plume ◽

Large Set ◽

Chemistry Transport Model ◽

Volcanic Plumes ◽

The Impact

Abstract. Volcanoes are a known source of halogens to the atmosphere. HBr volcanic emissions lead rapidly to the formation of BrO within volcanic plumes as shown by recent work based on observations and models. BrO, having a longer residence time in the atmosphere than HBr, is expected to have a significant impact on tropospheric chemistry, at least at the local and regional scales. The objective of this paper is to prepare a framework that will allow 3-D modelling of volcanic halogen emissions in order to determine their fate within the volcanic plume and then in the atmosphere at the regional and global scales. This work is based on a 1-D configuration of the chemistry transport model MOCAGE whose low computational cost allows us to perform a large set of sensitivity studies. This paper studies the Etna eruption on the 10 May 2008 that took place just before night time. Adaptations are made to MOCAGE to be able to produce the chemistry occurring within the volcanic plume. A simple sub-grid scale parameterization of the volcanic plume is implemented and tested. The use of this parameterization in a 0.5° × 0.5° configuration (typical regional resolution) has an influence on the partitioning between the various bromine compounds both during the eruption period and also during the night period immediately afterwards. During the day after the eruption, simulations both with and without parameterizations give very similar results that are consistent with the tropospheric column of BrO and SO2 in the volcanic plume derived from GOME-2 observations. Tests have been performed to evaluate the sensitivity of the results to the mixing between ambient air and the magmatic air at very high temperature at the crater vent that modifies the composition of the emission, and in particular the sulphate aerosol content that is key compound in the BrO production. Simulations show that the plume chemistry is not very sensitive to the assumptions used for the mixing parameter (relative quantity of ambient air mixed with magmatic air in the mixture) that is not well known. This is because there is no large change in the compounds limiting/favouring the BrO production in the plume. The impact of the model grid resolution is also tested in view of future 3-D-simulations at the global scale. A dilution of the emitted gases and aerosols is observed when using the typical global resolution (2°) as compared to a typical regional resolution (0.5°), as expected. Taking this into account, the results of the 2° resolution simulations are consistent with the GOME-2 observations. In general the simulations at 2° resolution are less efficient at producing BrO after the emission both with and without the subgrid-scale parameterization. The differences are mainly due to an interaction between concentration effects than stem from using a reduced volume in the 0.5° resolution combined with second order rate kinetics. The last series of tests were on the mean radius assumed for the sulphate aerosols that indirectly impacts the production of BrO by heterogeneous reactions. The simulations show that the BrO production is sensitive to this parameter with a stronger production when smaller aerosols are assumed. These results will be used to guide the implementation of volcanic halogen emissions in the 3-D configuration of MOCAGE.

Download Full-text

The impact of a future H<sub>2</sub>-based road transportation sector on the composition and chemistry of the atmosphere – Part 1: Tropospheric composition and air quality

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-19371-2012 ◽

2012 ◽

Vol 12 (8) ◽

pp. 19371-19421 ◽

Cited By ~ 1

Author(s):

D. Wang ◽

W. Jia ◽

S. C. Olsen ◽

D. J. Wuebbles ◽

M. K. Dubey ◽

...

Keyword(s):

Climate Change ◽

Air Quality ◽

Fossil Fuel ◽

Transport Model ◽

Sulfate Aerosol ◽

Road Transportation ◽

Chemistry Transport Model ◽

Transportation Sector ◽

The Impact ◽

Nitrate Aerosol

Abstract. Vehicles burning fossil fuel emit a number of substances that change the composition and chemistry of the atmosphere, and contribute to global air and water pollution and climate change. For example, nitrogen oxides and volatile organic compounds (VOCs) emitted as byproducts of fossil fuel combustion are key precursors to ground-level ozone and aerosol formation. In addition, on-road vehicles are major CO2 emitters. In order to tackle these problems, molecular hydrogen (H2) has been proposed as an energy carrier to substitute for fossil fuel in the future. However, before implementing any such strategy it is crucial to evaluate its potential impacts on air quality and climate. Here we evaluate the impact of a future (2050) H2-based road transportation sector on tropospheric chemistry and air quality for several possible growth and technology adoption scenarios. The growth scenarios are based on the high and low emissions Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios, A1FI and B1, respectively. The technological adoption scenarios include H2 fuel cell and H2 internal combustion engine options. The impacts are evaluated with the Community Atmospheric Model Chemistry global chemistry transport model (CAM-Chem). Higher resolution simulations focusing on the contiguous United States are also carried out with the Community Multiscale Air Quality Modeling System (CMAQ) regional chemistry transport model. For all scenarios future air quality improves with the adoption of a H2-based road transportation sector, however, the magnitude and type of improvement depend on the scenario. Model results show that with the adoption of H2 fuel cells decreases tropospheric burdens of ozone (7%), CO (14%), NOx (16%), soot (17%), sulfate aerosol (4%), and ammonium nitrate aerosol (12%) in the A1FI scenario, and decreases those of ozone (5%), CO (4%), NOx (11%), soot (7%), sulfate aerosol (4%), and ammonium nitrate aerosol (9 %) in the B1 scenario. The adoption of H2 internal combustion engines decreases tropospheric burdens of ozone (1%), CO (18%), soot (17%), and sulfate aerosol (3%) in the A1FI scenario, and decreases those of ozone (1%), CO (7%), soot (7%), and sulfate aerosol (3%) in the B1 scenario. In the future, people residing in the contiguous United States are expected to experience significantly fewer days of elevated levels of pollution if a H2 fuel cell road transportation sector is adopted. Health benefits of transitioning to a H2 economy for citizens in developing nations, like China and India, will be much more dramatic particularly in megacities with severe air-quality problems that are exacerbating.

Download Full-text

Assimilation of IASI satellite CO fields into a global chemistry transport model for validation against aircraft measurements

Atmospheric Chemistry and Physics ◽

10.5194/acp-12-4493-2012 ◽

2012 ◽

Vol 12 (10) ◽

pp. 4493-4512 ◽

Cited By ~ 19

Author(s):

A. Klonecki ◽

M. Pommier ◽

C. Clerbaux ◽

G. Ancellet ◽

J.-P. Cammas ◽

...

Keyword(s):

Transport Model ◽

Source Region ◽

Specific Treatment ◽

Arctic Region ◽

The Arctic ◽

Chemistry Transport Model ◽

Mixing Ratios ◽

High Concentrations ◽

The Impact

Abstract. This work evaluates the IASI CO product against independent in-situ aircraft data from the MOZAIC program and the POLARCAT aircraft campaign. The validation is carried out by analysing the impact of assimilation of eight months of IASI CO columns retrieved for the period of May to December 2008 into the global chemistry transport model LMDz-INCA. A modelling system based on a sub-optimal Kalman filter was developed and a specific treatment that takes into account the representativeness of observations at the scale of the model grid is applied to the IASI CO columns and associated errors before their assimilation in the model. Comparisons of the assimilated CO profiles with in situ CO measurements indicate that the assimilation leads to a considerable improvement of the model simulations in the middle troposphere as compared with a control run with no assimilation. Model biases in the simulation of background values are reduced and improvement in the simulation of very high concentrations is observed. The improvement is due to the transport by the model of the information present in the IASI CO retrievals. Our analysis also shows the impact of assimilation of CO on the representation of transport into the Arctic region during the POLARCAT summer campaign. A considerable increase in CO mixing ratios over the Asian source region was observed when assimilation was used leading to much higher values of CO during the cross-pole transport episode. These higher values are in good agreement with data from the POLARCAT flights that sampled this plume.

Download Full-text

Aerosol effects modeling using an online coupling between the meteorological model WRF and the chemistry-transport model CHIMERE

10.5194/gmd-2016-73 ◽

2016 ◽

Author(s):

Régis Briant ◽

Paolo Tuccella ◽

Adrien Deroubaix ◽

Dmitry Khvorostyanov ◽

Laurent Menut ◽

...

Keyword(s):

Optical Properties ◽

Transport Model ◽

Regional Scale ◽

Total Duration ◽

Radiation Budget ◽

Aerosol Optical Properties ◽

Chemistry Transport Model ◽

Meteorological Model ◽

Western Asia ◽

The Impact

Abstract. The presence of airborne aerosols affects the meteorology as it induces a perturbation in the radiation budget, the number of cloud condensation nuclei and the cloud micro-physics. Those effects are difficult to model at regional scale as several distinct models are usually involved. In this paper, the coupling of the CHIMERE chemistry-transport model with the WRF meteorological model using the OASIS3-MCT coupler is presented. WRF meteorological fields along with CHIMERE aerosol optical properties are exchanged through the coupler at a high frequency in order to model the aerosol direct and semidirect effects. The WRF-CHIMERE online model has a higher computational burden than both models ran separately in offline mode (up to 42 % higher). This is mainly due to some additional computations made within the models such as more frequent calls to meteorology treatment routines or calls to optical properties computations routines. On the other hand, the overall time required to perform the OASIS3-MCT exchanges is not significant compared to the total duration of the simulations. The impact of the coupling is evaluated on a case study over Europe, northern Africa, Middle East and western Asia during the Summer 2012, through comparisons of the offline and two online simulations (with and without the aerosol optical properties feedback) to observations of temperature, Aerosol Optical Depth (AOD) and surface PM10 (particulate matter with diameters lower than 10 µm) concentrations. Result shows that using the optical properties feedback induces a radiative forcing (average forcing of −4.8 W.m−2) which creates a perturbation in the average surface temperatures over desert areas (up to 2.6° locally) along with an increase of both AOD and PM10 concentrations.

Download Full-text

Interaction of anthropogenic and natural emission sources during a wild-land fire event – influence on ozone formation

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-3467-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 3467-3507

Author(s):

E. Bossioli ◽

M. Tombrou ◽

A. Karali ◽

A. Dandou ◽

D. Paronis ◽

...

Keyword(s):

Eastern Europe ◽

Transport Model ◽

Biogenic Emissions ◽

Fire Event ◽

Chemistry Transport Model ◽

Fire Emissions ◽

Natural Emission ◽

Lower Ratio ◽

The Impact ◽

Surface O3

Abstract. The objective of this study is to investigate the contribution of biomass burning in the formation of tropospheric O3. Furthermore, the impact of biogenic emissions under fire and no fire conditions is examined. This is achieved by applying the CAMx chemistry transport model for a wild-land fire event over Western Russia (24 April–10 May 2006). The model results are compared with O3 and isoprene observations from 117 and 9 stations of the EMEP network, respectively. Model computations show that the fire episode altered the O3 sensitivity in the area. In particular, the fire emissions increased surface O3 over Northern and Eastern Europe by up to 80% (40–45 ppb). In case of adopting a high fire NOx/CO emission ratio (0.06), the area (Eastern Europe and Western Russia) is characterized by VOC-sensitive O3 production and the impact of biogenic emissions is proven significant, contributing up to 8 ppb. Under a lower ratio (0.025), total surface O3 is almost doubled due to higher O3 production at the fire spots and lower fires' NO emissions. In this case as well as in the absence of fires, the impact of biogenic emissions is almost negligible. Injection height of the fire emissions accounted for O3 differences of the order of 10%, both at surface and over the planetary boundary layer (PBL).

Download Full-text

The impact of shipping emissions on air pollution in the Greater North Sea region – Part 2: Scenarios for 2030

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-15-11325-2015 ◽

2015 ◽

Vol 15 (8) ◽

pp. 11325-11368 ◽

Cited By ~ 1

Author(s):

V. Matthias ◽

A. Aulinger ◽

A. Backes ◽

J. Bieser ◽

B. Geyer ◽

...

Keyword(s):

North Sea ◽

Transport Model ◽

So2 Emissions ◽

Chemistry Transport Model ◽

The North ◽

International Regulations ◽

The North Sea ◽

Sea Area ◽

The Impact ◽

Ship Fuels

Abstract. Scenarios for future shipping emissions in the North Sea have been developed in the framework of the Clean North Sea Shipping project. The effects of changing NOx and SO2 emissions were invesigated with the chemistry transport model CMAQ for the year 2030 in the North Sea area. It has been found that, compared to today, the contribution of shipping to the NO2 and O3 concentrations will increase due to the expected enhanced traffic by more than 20 and 5%, respectively, by 2030 if no regulation for further emission reductions will be implemented in the North Sea area. PM2.5 will decrease slightly because the sulphur contents in ship fuels will be reduced as international regulations foresee. The effects differ largely between regions, seasons and date of the implementation of stricter regulations for NOx emissions from new built ships.

Download Full-text

Sensitivity of ensemble Lagrangian reconstructions to assimilated wind time step resolution

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-3155-2010 ◽

2010 ◽

Vol 10 (7) ◽

pp. 3155-3162 ◽

Cited By ~ 8

Author(s):

I. Pisso ◽

V. Marécal ◽

B. Legras ◽

G. Berthet

Keyword(s):

Time Series ◽

Transport Model ◽

Positive Impact ◽

Wind Fields ◽

Time Step ◽

Chemistry Transport Model ◽

Temporal And Spatial ◽

The Impact ◽

Optimal Space

Abstract. We study the impact of temporal and spatial resolution and changes in modelled meteorological winds in the context of diffusive ensemble Lagrangian reconstructions. In situ tracer measurements are modelled based on coarse resolution global 3-D tracer distributions from a chemistry-transport model and on different time series of meteorological wind fields including a special set of 1-hourly analysed winds which is compared with 3 and 6-hourly operational analysed winds and with 3-hourly ERA-interim reanalysis. Increasing the time resolution of the advecting winds from three to one hour using the operational winds provides an improvement on diffusive reconstructions in the period studied but smaller than that obtained from six to three hours. The positive impact of using 1-hourly winds is similar to that obtained using ERA-Interim 3-hourly winds instead of the 3-hourly ECMWF operational analysis for the same period. This study sets out a technique to quantify differences in time series of meteorological wind fields here applied to assess the optimal space and time resolutions for ensemble Lagrangian reconstructions in the lower stratosphere.

Download Full-text

Impact of uncertainties in inorganic chemical rate constants on tropospheric composition and ozone radiative forcing

Atmospheric Chemistry and Physics ◽

10.5194/acp-17-14333-2017 ◽

2017 ◽

Vol 17 (23) ◽

pp. 14333-14352 ◽

Cited By ~ 16

Author(s):

Ben Newsome ◽

Mat Evans

Keyword(s):

Rate Constant ◽

Atmospheric Chemistry ◽

Rate Constants ◽

Tropospheric Ozone ◽

Radiative Forcing ◽

Transport Model ◽

Surface Ozone ◽

Chemistry Transport Model ◽

The Impact ◽

Chemical Rate

Abstract. Chemical rate constants determine the composition of the atmosphere and how this composition has changed over time. They are central to our understanding of climate change and air quality degradation. Atmospheric chemistry models, whether online or offline, box, regional or global, use these rate constants. Expert panels evaluate laboratory measurements, making recommendations for the rate constants that should be used. This results in very similar or identical rate constants being used by all models. The inherent uncertainties in these recommendations are, in general, therefore ignored. We explore the impact of these uncertainties on the composition of the troposphere using the GEOS-Chem chemistry transport model. Based on the Jet Propulsion Laboratory (JPL) and International Union of Pure and Applied Chemistry (IUPAC) evaluations we assess the influence of 50 mainly inorganic rate constants and 10 photolysis rates on tropospheric composition through the use of the GEOS-Chem chemistry transport model. We assess the impact on four standard metrics: annual mean tropospheric ozone burden, surface ozone and tropospheric OH concentrations, and tropospheric methane lifetime. Uncertainty in the rate constants for NO2 + OH →M  HNO3 and O3 + NO  →  NO2 + O2 are the two largest sources of uncertainty in these metrics. The absolute magnitude of the change in the metrics is similar if rate constants are increased or decreased by their σ values. We investigate two methods of assessing these uncertainties, addition in quadrature and a Monte Carlo approach, and conclude they give similar outcomes. Combining the uncertainties across the 60 reactions gives overall uncertainties on the annual mean tropospheric ozone burden, surface ozone and tropospheric OH concentrations, and tropospheric methane lifetime of 10, 11, 16 and 16 %, respectively. These are larger than the spread between models in recent model intercomparisons. Remote regions such as the tropics, poles and upper troposphere are most uncertain. This chemical uncertainty is sufficiently large to suggest that rate constant uncertainty should be considered alongside other processes when model results disagree with measurement. Calculations for the pre-industrial simulation allow a tropospheric ozone radiative forcing to be calculated of 0.412 ± 0.062 W m−2. This uncertainty (13 %) is comparable to the inter-model spread in ozone radiative forcing found in previous model–model intercomparison studies where the rate constants used in the models are all identical or very similar. Thus, the uncertainty of tropospheric ozone radiative forcing should expanded to include this additional source of uncertainty. These rate constant uncertainties are significant and suggest that refinement of supposedly well-known chemical rate constants should be considered alongside other improvements to enhance our understanding of atmospheric processes.

Download Full-text