scholarly journals Equilibrium of sinks and sources of sulphate over Europe: comparison between a six-year simulation and EMEP observations

2009 ◽  
Vol 9 (13) ◽  
pp. 4505-4519 ◽  
Author(s):  
M. Ménégoz ◽  
D. Salas y Melia ◽  
M. Legrand ◽  
H. Teyssèdre ◽  
M. Michou ◽  
...  
Keyword(s):  
Transport Model ◽  
Weather Conditions ◽  
General Tendency ◽  
Chemistry Transport Model ◽  
Annual Variations ◽  
Sulphur Cycle ◽  
Sulphate Aerosols ◽  
Chemical Scheme ◽  
One Year ◽  
Year 2000

Abstract. Sulphate distributions were simulated with a global chemistry transport model. A chemical scheme describing the sulphur cycle and the parameterisations of the main sinks for sulphate aerosols were included in the model. A six-year simulation was conducted from the years 2000 to 2005, driven by the ECMWF operational analyses. Emissions come from an inventory representative of the year 2000. This paper focuses on the analysis of the sulphate sinks and sources over Europe for the entire period of simulation. The Sulphate burden shows a marked annual cycle, which is the result of the annual variations of the aqueous and gaseous chemistry. Regionally, the monthly mean aerosol burden can vary by a factor of 2 from one year to another, because of different weather conditions, driving chemistry, transport and wet deposition of sulphate aerosols. Sulphate ground concentrations, scavenging fluxes and precipitation modelled were compared with observations. The model represents quite well sulphate fields over Europe, but has a general tendency to overestimate sulphate ground concentrations, in particular over Northern Europe. We assume that it is linked to the representation of the scavenging fluxes, which are underestimated. We suggest that uncertainties in modelled precipitation explain only partially the underestimation of the scavenging fluxes in the model.

scholarly journals Equilibrium of sinks and sources of sulphate over Europe: comparison between a six-year simulation and EMEP observations

2009 ◽  
Vol 9 (1) ◽  
pp. 4381-4415
Author(s):  
M. Ménégoz ◽  
D. Salas y Melia ◽  
M. Legrand ◽  
H. Teyssèdre ◽  
M. Michou ◽  
...  
Keyword(s):  
Transport Model ◽  
Meteorological Conditions ◽  
Northern Europe ◽  
General Tendency ◽  
Chemistry Transport Model ◽  
Annual Variations ◽  
Sulphur Cycle ◽  
Sulphate Aerosols ◽  
Chemical Scheme ◽  
Year 2000

Abstract. Sulphate distributions were simulated with a global chemistry transport model. A chemical scheme describing the sulphur cycle and the parameterisations of the main sinks for sulphate aerosols were included in the model. A six-year simulation was conducted from the years 2000 to 2005, driven by the ECMWF operational analyses. Emissions come from an inventory representative of the year 2000. This paper focuses on the analysis of the sulphate sinks and sources over Europe for the entire period of simulation. The Sulphate burden shows a marked annual cycle, which is the result of the annual variations of the aqueous and gaseous chemistry. Sulphate columns can vary regionally by 100% between different years, due to meteorological conditions, driving chemistry, transport and wet deposition of sulphate aerosols. Sulphate ground concentrations, scavenging fluxes and precipitation modelled were compared with observations. The model represents quite well sulphate fields over Europe, but has a general tendency to overestimate sulphate ground concentrations, in particular over Northern Europe. We assume that it is linked to the representation of the scavenging fluxes, which are underestimated. We suggest that uncertainties in modelled precipitation explain only partially the underestimation of the scavenging fluxes in the model.

scholarly journals The On-Line Integrated Mesoscale Chemistry Model BOLCHEM

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 192
Author(s):  
Rita Cesari ◽  
Tony Christian Landi ◽  
Massimo D’Isidoro ◽  
Mihaela Mircea ◽  
Felicita Russo ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Transport Model ◽  
Horizontal Resolution ◽  
Integration Step ◽  
Chemistry Transport Model ◽  
European Environmental Agency ◽  
On Line ◽  
One Year ◽  
Pm2.5 And Pm10 ◽  
Monitoring Service

This work presents the on-line coupled meteorology–chemistry transport model BOLCHEM, based on the hydrostatic meteorological BOLAM model, the gas chemistry module SAPRC90, and the aerosol dynamic module AERO3. It includes parameterizations to describe natural source emissions, dry and wet removal processes, as well as the transport and dispersion of air pollutants. The equations for different processes are solved on the same grid during the same integration step, by means of a time-split scheme. This paper describes the model and its performance at horizontal resolution of 0.2∘× 0.2∘ over Europe and 0.1∘× 0.1∘ in a nested configuration over Italy, for one year run (December 2009–November 2010). The model has been evaluated against the AIRBASE data of the European Environmental Agency. The basic statistics for higher resolution simulations of O3, NO2 and particulate matter concentrations (PM2.5 and PM10) have been compared with those from Copernicus Atmosphere Monitoring Service (CAMS) ensemble median. In summer, for O3 we found a correlation coefficient R of 0.72 and mean bias of 2.15 over European domain and a correlation coefficient R of 0.67 and mean bias of 2.36 over Italian domain. PM10 and PM2.5 are better reproduced in the winter, the latter with a correlation coefficient R of 0.66 and the mean bias MB of 0.35 over Italian domain.

scholarly journals What drives the observed variability of HCN in the troposphere and lower stratosphere?

2009 ◽  
Vol 9 (21) ◽  
pp. 8531-8543 ◽  
Author(s):  
Q. Li ◽  
P. I. Palmer ◽  
H. C. Pumphrey ◽  
P. Bernath ◽  
E. Mahieu
Keyword(s):  
Atmospheric Chemistry ◽  
Lower Stratosphere ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Negative Bias ◽  
Mixing Ratio ◽  
Chemistry Transport Model ◽  
Annual Variations ◽  
Surface Emission ◽  
Chemistry Experiment

Abstract. We use the GEOS-Chem global 3-D chemistry transport model to investigate the relative importance of chemical and physical processes that determine observed variability of hydrogen cyanide (HCN) in the troposphere and lower stratosphere. Consequently, we reconcile ground-based FTIR column measurements of HCN, which show annual and semi-annual variations, with recent space-borne measurements of HCN mixing ratio in the tropical lower stratosphere, which show a large two-year variation. We find that the observed column variability over the ground-based stations is determined by a superposition of HCN from several regional burning sources, with GEOS-Chem reproducing these column data with a positive bias of 5%. GEOS-Chem reproduces the observed HCN mixing ratio from the Microwave Limb Sounder and the Atmospheric Chemistry Experiment satellite instruments with a mean negative bias of 20%, and the observed HCN variability with a mean negative bias of 7%. We show that tropical biomass burning emissions explain most of the observed HCN variations in the upper troposphere and lower stratosphere (UTLS), with the remainder due to atmospheric transport and HCN chemistry. In the mid and upper stratosphere, atmospheric dynamics progressively exerts more influence on HCN variations. The extent of temporal overlap between African and other continental burning seasons is key in establishing the apparent bienniel cycle in the UTLS. Similar analysis of other, shorter-lived trace gases have not observed the transition between annual and bienniel cycles in the UTLS probably because the signal of inter-annual variations from surface emission has been diluted before arriving at the lower stratosphere (LS), due to shorter atmospheric lifetimes.

scholarly journals Impact of the vertical emission profiles on background gas-phase pollution simulated from the EMEP emissions over Europe

2013 ◽  
Vol 13 (12) ◽  
pp. 5987-5998 ◽  
Author(s):  
S. Mailler ◽  
D. Khvorostyanov ◽  
L. Menut
Keyword(s):  
Air Quality ◽  
Gas Phase ◽  
Recent Literature ◽  
Transport Model ◽  
Anthropogenic Emissions ◽  
Vertical Profiles ◽  
Chemistry Transport Model ◽  
Vertical Injection ◽  
One Year ◽  
Background Gas

Abstract. Five one-year air quality simulations over a domain covering Europe have been performed using the CHIMERE chemistry transport model and the EMEP emission dataset for Europe. These five simulations differ only by the representation of the effective emission heights for anthropogenic emissions: one has been run using the EMEP standard recommendations, three others with vertical injection profiles derived from the EMEP recommendations but multiplying the injection height by 0.75, 0.50 and 0.25, respectively, while the last one uses vertical profiles derived from the recent literature. It is shown that using injection heights lower than the EMEP recommendations leads to significantly improved simulation of background SO2, NO2 and O3 concentrations when compared to the Airbase station measurements.

scholarly journals Impact of the vertical emission profiles on ground-level gas-phase pollution simulated from the EMEP emissions over Europe

2013 ◽  
Vol 13 (2) ◽  
pp. 3663-3693
Author(s):  
S. Mailler ◽  
D. Khvorostyanov ◽  
L. Menut
Keyword(s):  
Air Quality ◽  
Gas Phase ◽  
Recent Literature ◽  
Transport Model ◽  
Ground Level ◽  
Anthropogenic Emissions ◽  
Vertical Profiles ◽  
Chemistry Transport Model ◽  
Vertical Injection ◽  
One Year

Abstract. Five one-year air quality simulations over a domain covering Europe have been performed using the CHIMERE chemistry transport model and the EMEP emission dataset for Europe. These five simulations differ only by the representation of the effective emission heights for anthropogenic emissions: one has been run using the EMEP standard recommandations, three others with vertical injection profiles derived from the EMEP recommandations but multiplying the injection height by respectively 0.75, 0.50 and 0.25, while the last one uses vertical profiles derived from the recent literature. It is shown that using injection heights lower than the EMEP recommandations leads to significantly improved simulation of SO2, NO2 and O3 concentrations when compared to the Airbase station measurements.

scholarly journals What drives the observed variability of HCN in the troposphere and lower stratosphere?

2009 ◽  
Vol 9 (3) ◽  
pp. 10883-10912 ◽  
Author(s):  
Q. Li ◽  
P. I. Palmer ◽  
H. C. Pumphrey ◽  
P. Bernath ◽  
E. Mahieu
Keyword(s):  
Atmospheric Chemistry ◽  
Lower Stratosphere ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Chemistry Transport Model ◽  
Upper Troposphere ◽  
Annual Variations ◽  
Surface Emission ◽  
Chemistry Experiment ◽  
Temporal Overlap

Abstract. We use the GEOS-Chem global 3-D chemistry transport model to investigate the relative importance of chemical and physical processes that determine observed variability of hydrogen cyanide (HCN) in the troposphere and lower stratosphere. Consequently, we reconcile ground-based FTIR column measurements of HCN, which show annual and semi-annual variations, with recent space-borne measurements of HCN mixing ratio in the tropical lower stratosphere, which show a large two-year variation. We find that the observed column variability over the ground-based stations is determined by a superposition of HCN from several regional burning sources, with GEOS-Chem reproducing these column data with a positive bias of 5%. GEOS-Chem reproduces the observed tropical HCN variability from the Microwave Limb Sounder and the Atmospheric Chemistry Experiment satellite instruments with a negative bias of 7%. We show the tropical biomass burning emissions explain mostly the observed HCN variations in the upper troposphere and lower stratosphere (UTLS), with the remainder due to atmospheric transport and HCN chemistry. In the mid and upper stratosphere, atmospheric dynamics progressively exerts more influences on HCN variations. The extent of temporal overlap between African and other continental burning seasons is key in establishing the apparent bienniel cycle in the UTLS. Similar analysis of other, shorter-lived trace gases have not observed the transition between annual and bienniel cycles in the UTLS probably because the signal of inter-annual variations from surface emission has vanished before arriving at the lower stratosphere (LS), due to shorter atmospheric lifetimes.

scholarly journals Anthropogenic influence on SOA and the resulting radiative forcing

2009 ◽  
Vol 9 (8) ◽  
pp. 2715-2728 ◽  
Author(s):  
C. R. Hoyle ◽  
G. Myhre ◽  
T. K. Berntsen ◽  
I. S. A. Isaksen
Keyword(s):  
Radiative Forcing ◽  
Transport Model ◽  
Organic Aerosols ◽  
Aerosol Chemistry ◽  
Sulphate Aerosol ◽  
Chemistry Transport Model ◽  
Sulphate Aerosols ◽  
Ipcc Report ◽  
The Difference ◽  
Different Sources

Abstract. The effect of chemical changes in the atmosphere since the pre-industrial period on the distributions and burdens of Secondary Organic Aerosol (SOA) has been calculated using the off-line aerosol chemistry transport model Oslo CTM2. The production of SOA was found to have increased from about 35 Tg yr−1 to 53 Tg yr−1 since pre-industrial times, leading to an increase in the global annual mean SOA burden from 0.33 Tg to 0.50 Tg, or about 51%. The effect of allowing semi-volatile species to partition to sulphate aerosol was also tested, leading to an increase in SOA production from about 43 Tg yr−1 to 69 Tg yr−1 since pre-industrial times, while the annual mean SOA burden increased from 0.44 Tg to 0.70 Tg, or about 59%. The increases were greatest over industrialised areas, especially when partitioning to sulphate aerosol was allowed, as well as over regions with high biogenic precursor emissions. The contribution of emissions from different sources to the larger SOA burdens has been calculated. The results suggest that the majority of the increase was caused by emissions of primary organic aerosols (POA), from fossil fuel and bio fuel combustion. As yet, very few radiative forcing estimates of SOA exist, and no such estimates were provided in the latest IPCC report. In this study, we found that the change in SOA burden caused a radiative forcing (defined here as the difference between the pre-industrial and the present day run) of −0.09 W m−2, when SOA was allowed to partition to both organic and sulphate aerosols, and −0.06 W m−2 when only partitioning to organic aerosols was assumed. Therefore, the radiative forcing of SOA was found to be stronger than the best estimate for POA in the latest IPCC assessment.

scholarly journals On the consistency between global and regional methane emissions inferred from SCIAMACHY, TANSO-FTS, IASI and surface measurements

2014 ◽  
Vol 14 (2) ◽  
pp. 577-592 ◽  
Author(s):  
C. Cressot ◽  
F. Chevallier ◽  
P. Bousquet ◽  
C. Crevoisier ◽  
E. J. Dlugokencky ◽  
...  
Keyword(s):  
Near Infrared ◽  
Transport Model ◽  
Methane Emissions ◽  
Chemistry Transport Model ◽  
Satellite Retrievals ◽  
Surface Measurements ◽  
Scanning Imaging ◽  
One Year ◽  
The One ◽  
Global Emissions

Abstract. Satellite retrievals of methane weighted atmospheric columns are assimilated within a Bayesian inversion system to infer the global and regional methane emissions and sinks for the period August 2009 to July 2010. Inversions are independently computed from three different space-borne observing systems and one surface observing system under several hypotheses for prior-flux and observation errors. Posterior methane emissions are compared and evaluated against surface mole fraction observations via a chemistry-transport model. Apart from SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CartograpHY), the simulations agree fairly well with the surface mole fractions. The most consistent configurations of this study using TANSO-FTS (Thermal And Near infrared Sensor for carbon Observation – Fourier Transform Spectrometer), IASI (Infrared Atmospheric Sounding Interferometer) or surface measurements induce posterior methane global emissions of, respectively, 565 ± 21 Tg yr−1, 549 ± 36 Tg yr−1 and 538 ± 15 Tg yr−1 over the one-year period August 2009–July 2010. This consistency between the satellite retrievals (apart from SCIAMACHY) and independent surface measurements is promising for future improvement of CH4 emission estimates by atmospheric inversions.

scholarly journals Anthropogenic influence on SOA and the resulting radiative forcing

2008 ◽  
Vol 8 (6) ◽  
pp. 18911-18936 ◽  
Author(s):  
C. R. Hoyle ◽  
G. Myhre ◽  
T. K. Berntsen ◽  
I. S. A. Isaksen
Keyword(s):  
Radiative Forcing ◽  
Transport Model ◽  
Organic Aerosols ◽  
Organic Aerosol ◽  
Aerosol Chemistry ◽  
Chemistry Transport Model ◽  
Sulphate Aerosols ◽  
Ipcc Report ◽  
Production Increase ◽  
Different Sources

Abstract. The pre-industrial and present day distributions and burdens of Secondary Organic Aerosol (SOA) have been calculated using the off-line aerosol chemistry transport model Oslo CTM2. The production of SOA was found to have increased from about 43 Tg yr−1 to 69 Tg yr−1 since pre-industrial times, leading to an increase in the global annual mean SOA burden from 0.44 Tg to 0.70 Tg, or about 59%. The increases are greatest over industrialised areas, as well as over regions with high biogenic precursor emissions. The contribution of emissions from different sources to the larger SOA burdens has been calculated. The results suggest that the majority of the increase is caused by emissions of primary organic aerosols (POA), from fossil fuel and bio fuel combustion. When SOA partitioning to ammonium sulphate aerosol was not accounted for, the increase in SOA burden between pre-industrial times and the present was found to be lower (51%), with a production increase of 55%. As yet, very few radiative forcing estimates of SOA exist, and no such estimates were provided in the latest IPCC report. In this study, we find that the change in SOA burden caused a radiative forcing of −0.09 W m−2, when SOA was allowed to partition to both organic and sulphate aerosols, and −0.06 W m−2 when only partitioning to organic aerosols was assumed. Therefore, the radiative forcing of SOA is found to be substantially stronger than the best estimate for POA in the latest IPCC assessment.

scholarly journals Variability of springtime transpacific pollution transport during 2000–2006: the INTEX-B mission in the context of previous years

2010 ◽  
Vol 10 (3) ◽  
pp. 1345-1359 ◽  
Author(s):  
G. G. Pfister ◽  
L. K. Emmons ◽  
D. P. Edwards ◽  
A. Arellano ◽  
T. Campos ◽  
...  
Keyword(s):  
Transport Model ◽  
Pollution Transport ◽  
Chemistry Transport Model ◽  
Pollution Levels ◽  
Annual Variability ◽  
Source Regions ◽  
Time Period ◽  
The Pacific ◽  
The Us ◽  
Transport Experiment

Abstract. We analyze the transport of pollution across the Pacific during the NASA INTEX-B (Intercontinental Chemical Transport Experiment Part B) campaign in spring 2006 and examine how this year compares to the time period for 2000 through 2006. In addition to aircraft measurements of carbon monoxide (CO) collected during INTEX-B, we include in this study multi-year satellite retrievals of CO from the Measurements of Pollution in the Troposphere (MOPITT) instrument and simulations from the chemistry transport model MOZART-4. Model tracers are used to examine the contributions of different source regions and source types to pollution levels over the Pacific. Additional modeling studies are performed to separate the impacts of inter-annual variability in meteorology and dynamics from changes in source strength. Interannual variability in the tropospheric CO burden over the Pacific and the US as estimated from the MOPITT data range up to 7% and a somewhat smaller estimate (5%) is derived from the model. When keeping the emissions in the model constant between years, the year-to-year changes are reduced (2%), but show that in addition to changes in emissions, variable meteorological conditions also impact transpacific pollution transport. We estimate that about 1/3 of the variability in the tropospheric CO loading over the contiguous US is explained by changes in emissions and about 2/3 by changes in meteorology and transport. Biomass burning sources are found to be a larger driver for inter-annual variability in the CO loading compared to fossil and biofuel sources or photochemical CO production even though their absolute contributions are smaller. Source contribution analysis shows that the aircraft sampling during INTEX-B was fairly representative of the larger scale region, but with a slight bias towards higher influence from Asian contributions.

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