Aerosol Dynamics Modelling in the Regional Chemistry Transport Model System Eurad

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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The On-Line Integrated Mesoscale Chemistry Model BOLCHEM

Atmosphere ◽

10.3390/atmos12020192 ◽

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.

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Top-Down NOX Emissions of European Cities Based on the Downwind Plume of Modelled and Space-Borne Tropospheric NO2 Columns

Sensors ◽

10.3390/s18092893 ◽

2018 ◽

Vol 18 (9) ◽

pp. 2893 ◽

Cited By ~ 3

Author(s):

Willem W. Verstraeten ◽

Klaas Folkert Boersma ◽

John Douros ◽

Jason E. Williams ◽

Henk Eskes ◽

...

Keyword(s):

Urban Areas ◽

Transport Model ◽

Nox Emissions ◽

Inventory Data ◽

Ozone Monitoring Instrument ◽

Top Down ◽

Chemistry Transport Model ◽

European Cities ◽

Tropospheric No2

Top-down estimates of surface NOX emissions were derived for 23 European cities based on the downwind plume decay of tropospheric nitrogen dioxide (NO2) columns from the LOTOS-EUROS (Long Term Ozone Simulation-European Ozone Simulation) chemistry transport model (CTM) and from Ozone Monitoring Instrument (OMI) satellite retrievals, averaged for the summertime period (April–September) during 2013. Here we show that the top-down NOX emissions derived from LOTOS-EUROS for European urban areas agree well with the bottom-up NOX emissions from the MACC-III inventory data (R2 = 0.88) driving the CTM demonstrating the potential of this method. OMI top-down NOX emissions over the 23 European cities are generally lower compared with the MACC-III emissions and their correlation is slightly lower (R2 = 0.79). The uncertainty on the derived NO2 lifetimes and NOX emissions are on average ~55% for OMI and ~63% for LOTOS-EUROS data. The downwind NO2 plume method applied on both LOTOS-EUROS and OMI tropospheric NO2 columns allows to estimate NOX emissions from urban areas, demonstrating that this is a useful method for real-time updates of urban NOX emissions with reasonable accuracy.

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Validation of nine years of MOPITT V5 NIR using MOZAIC/IAGOS measurements: biases and long-term stability

Atmospheric Measurement Techniques ◽

10.5194/amt-7-3783-2014 ◽

2014 ◽

Vol 7 (11) ◽

pp. 3783-3799 ◽

Cited By ~ 8

Author(s):

A. T. J. de Laat ◽

I. Aben ◽

M. Deeter ◽

P. Nédélec ◽

H. Eskes ◽

...

Keyword(s):

Near Infrared ◽

Transport Model ◽

A Priori ◽

Validation Data ◽

Chemistry Transport Model ◽

Large Variability ◽

Long Term Stability ◽

Spatio Temporal ◽

Good Agreement

Abstract. Validation results from a comparison between Measurement Of Pollution In The Troposphere (MOPITT) V5 Near InfraRed (NIR) carbon monoxide (CO) total column measurements and Measurement of Ozone and Water Vapour on Airbus in-service Aircraft (MOZAIC)/In-Service Aircraft for a Global Observing System (IAGOS) aircraft measurements are presented. A good agreement is found between MOPITT and MOZAIC/IAGOS measurements, consistent with results from earlier studies using different validation data and despite large variability in MOPITT CO total columns along the spatial footprint of the MOZAIC/IAGOS measurements. Validation results improve when taking the large spatial footprint of the MOZAIC/IAGOS data into account. No statistically significant drift was detected in the validation results over the period 2002–2010 at global, continental and local (airport) scales. Furthermore, for those situations where MOZAIC/IAGOS measurements differed from the MOPITT a priori, the MOPITT measurements clearly outperformed the MOPITT a priori data, indicating that MOPITT NIR retrievals add value to the MOPITT a priori. Results from a high spatial resolution simulation of the chemistry-transport model MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle) showed that the most likely explanation for the large MOPITT variability along the MOZAIC-IAGOS profile flight path is related to spatio-temporal CO variability, which should be kept in mind when using MOZAIC/IAGOS profile measurements for validating satellite nadir observations.

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An alternative way to evaluate chemistry-transport model variability

Geoscientific Model Development ◽

10.5194/gmd-10-1199-2017 ◽

2017 ◽

Vol 10 (3) ◽

pp. 1199-1208 ◽

Cited By ~ 1

Author(s):

Laurent Menut ◽

Sylvain Mailler ◽

Bertrand Bessagnet ◽

Guillaume Siour ◽

Augustin Colette ◽

...

Keyword(s):

Transport Model ◽

Model Performance ◽

Error Statistics ◽

Chemistry Transport Model ◽

Temporal Correlations ◽

Time Period ◽

The Difference ◽

Model Variability ◽

Spatial Locations ◽

Statistical Indicators

Abstract. A simple and complementary model evaluation technique for regional chemistry transport is discussed. The methodology is based on the concept that we can learn about model performance by comparing the simulation results with observational data available for time periods other than the period originally targeted. First, the statistical indicators selected in this study (spatial and temporal correlations) are computed for a given time period, using colocated observation and simulation data in time and space. Second, the same indicators are used to calculate scores for several other years while conserving the spatial locations and Julian days of the year. The difference between the results provides useful insights on the model capability to reproduce the observed day-to-day and spatial variability. In order to synthesize the large amount of results, a new indicator is proposed, designed to compare several error statistics between all the years of validation and to quantify whether the period and area being studied were well captured by the model for the correct reasons.

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Diagnosing the transition layer at extratropical latitudes using MLS O<sub>3</sub> and MOPITT CO analyses

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-7225-2013 ◽

2013 ◽

Vol 13 (14) ◽

pp. 7225-7240 ◽

Cited By ~ 9

Author(s):

J. Barré ◽

L. El Amraoui ◽

P. Ricaud ◽

W. A. Lahoz ◽

J.-L. Attié ◽

...

Keyword(s):

Data Assimilation ◽

Transition Region ◽

Transition Layer ◽

Transport Model ◽

Global Scale ◽

British Isles ◽

Chemistry Transport Model ◽

Free Model ◽

The Relationship

Abstract. The behavior of the extratropical transition layer (ExTL) is investigated using a chemistry transport model (CTM) and analyses derived from assimilation of MLS (Microwave Limb Sounder) O3 and MOPITT (Measurements Of Pollution In The Troposphere) CO data. We firstly focus on a stratosphere–troposphere exchange (STE) case study that occurred on 15 August 2007 over the British Isles (50° N, 10° W). We evaluate the effect of data assimilation on the O3–CO correlations. It is shown that data assimilation disrupts the relationship in the transition region. When MLS O3 is assimilated, CO and O3 values are not consistent between each other, leading to unphysical correlations at the STE location. When MLS O3 and MOPITT CO assimilated fields are taken into account in the diagnostics the relationship happens to be more physical. We then use O3–CO correlations to quantify the effect of data assimilation on the height and depth of the ExTL. When the free-model run O3 and CO fields are used in the diagnostics, the ExTL distribution is found 1.1 km above the thermal tropopause and is 2.6 km wide (2σ). MOPITT CO analyses only slightly sharpen (by −0.02 km) and lower (by −0.2 km) the ExTL distribution. MLS O3 analyses provide an expansion (by +0.9 km) of the ExTL distribution, suggesting a more intense O3 mixing. However, the MLS O3 analyses ExTL distribution shows a maximum close to the thermal tropopause and a mean location closer to the thermal tropopause (+0.45 km). When MLS O3 and MOPITT CO analyses are used together, the ExTL shows a mean location that is the closest to the thermal tropopause (+0.16 km). We also extend the study at the global scale on 15 August 2007 and for the month of August 2007. MOPITT CO analyses still show a narrower chemical transition between stratosphere and troposphere than the free-model run. MLS O3 analyses move the ExTL toward the troposphere and broaden it. When MLS O3 analyses and MOPITT CO analyses are used together, the ExTL matches the thermal tropopause poleward of 50°.

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Modeling anthropogenically controlled secondary organic aerosols in a megacity: a simplified framework for global and climate models

Geoscientific Model Development ◽

10.5194/gmd-4-901-2011 ◽

2011 ◽

Vol 4 (4) ◽

pp. 901-917 ◽

Cited By ~ 73

Author(s):

A. Hodzic ◽

J. L. Jimenez

Keyword(s):

Mexico City ◽

Biomass Burning ◽

Climate Models ◽

Transport Model ◽

Anthropogenic Pollution ◽

Temporal Variations ◽

Anthropogenic Sources ◽

Organic Vapors ◽

Chemistry Transport Model ◽

Evolution Of Oxygen

Abstract. A simplified parameterization for secondary organic aerosol (SOA) formation in polluted air and biomass burning smoke is tested and optimized in this work, towards the goal of a computationally inexpensive method to calculate pollution and biomass burning SOA mass and hygroscopicity in global and climate models. A regional chemistry-transport model is used as the testbed for the parameterization, which is compared against observations from the Mexico City metropolitan area during the MILAGRO 2006 field experiment. The empirical parameterization is based on the observed proportionality of SOA concentrations to excess CO and photochemical age of the airmass. The approach consists in emitting an organic gas as lumped SOA precursor surrogate proportional to anthropogenic or biomass burning CO emissions according to the observed ratio between SOA and CO in aged air, and reacting this surrogate with OH into a single non-volatile species that condenses to form SOA. An emission factor of 0.08 g of the lumped SOA precursor per g of CO and a rate constant with OH of 1.25 × 10−11 cm3 molecule−1 s−1 reproduce the observed average SOA mass within 30 % in the urban area and downwind. When a 2.5 times slower rate is used (5 × 10−12 cm3 molecule−1 s−1) the predicted SOA amount and temporal evolution is nearly identical to the results obtained with SOA formation from semi-volatile and intermediate volatility primary organic vapors according to the Robinson et al. (2007) formulation. Our simplified method has the advantage of being much less computationally expensive than Robinson-type methods, and can be used in regions where the emissions of SOA precursors are not yet available. As the aged SOA/ΔCO ratios are rather consistent globally for anthropogenic pollution, this parameterization could be reasonably tested in and applied to other regions. The evolution of oxygen-to-carbon ratio was also empirically modeled and the predicted levels were found to be in reasonable agreement with observations. The potential enhancement of biogenic SOA by anthropogenic pollution, which has been suggested to play a major role in global SOA formation, is also tested using two simple parameterizations. Our results suggest that the pollution enhancement of biogenic SOA could provide additional SOA, but does not however explain the concentrations or the spatial and temporal variations of measured SOA mass in the vicinity of Mexico City, which appears to be controlled by anthropogenic sources. The contribution of the biomass burning to the predicted SOA is less than 10% during the studied period.

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Representation of aerosol optical properties using a chemistry transport model to improve solar irradiance modelling

Solar Energy ◽

10.1016/j.solener.2018.10.017 ◽

2018 ◽

Vol 176 ◽

pp. 439-452 ◽

Cited By ~ 1

Author(s):

Karine Sartelet ◽

Carole Legorgeu ◽

Lya Lugon ◽

Yassine Maanane ◽

Luc Musson-Genon

Keyword(s):

Optical Properties ◽

Solar Irradiance ◽

Transport Model ◽

Aerosol Optical Properties ◽

Chemistry Transport Model

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Intercomparison of modal and sectional aerosol microphysics representations within the same 3-D global chemical transport model

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-623-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 623-689 ◽

Cited By ~ 2

Author(s):

G. W. Mann ◽

K. S. Carslaw ◽

D. A. Ridley ◽

D. V. Spracklen ◽

K. J. Pringle ◽

...

Keyword(s):

Size Distribution ◽

Transport Model ◽

Cloud Condensation Nuclei ◽

Particle Growth ◽

Free Troposphere ◽

Chemical Transport Model ◽

Condensation Nuclei ◽

Chemistry Transport Model ◽

Surface Mass ◽

Cloud Processing

Abstract. A global modal aerosol microphysics module (GLOMAP-mode) is evaluated and improved by comparing against a sectional version (GLOMAP-bin) and observations in the same 3-D global offline chemistry transport model. With both schemes, the model captures the main features of the global particle size distribution, with sub-micron aerosol approximately unimodal in continental regions and bi-modal in marine regions. Initial bin-mode comparisons showed that various size distribution parameter settings (mode widths and inter-modal separation sizes) resulted in clear biases compared to the sectional scheme. By adjusting these parameters in the modal scheme, much better agreement is achieved against the bin scheme and observations. Surface mass of sulphate, sea-salt, black carbon (BC) and organic carbon (OC) are, on the annual mean, within 25 % in the two schemes in nearly all regions. On the annual mean, surface level concentrations of condensation nuclei (CN), cloud condensation nuclei (CCN), surface area density and condensation sink also compare within 25 % in most regions. However, marine CCN concentrations between 30° N and 30° S are systematically higher in the modal scheme, by 25–60 %, which we attribute to differences in size-resolved particle growth or cloud-processing. Larger differences also exist in regions or seasons dominated by biomass burning and in free-troposphere and high-latitude regions. Indeed, in the free-troposphere, GLOMAP-mode BC is a factor 2–4 higher than GLOMAP-bin, likely due to differences in size-resolved scavenging. Nevertheless, in most parts of the atmosphere, we conclude that bin-mode differences are much less than model-observation differences, although some processes are missing in these runs which may pose a bigger challenge to modal schemes (e.g. boundary layer nucleation, ultra-fine sea-spray). The findings here underline the need for a spectrum of complexity in global models, with size-resolved aerosol properties predicted by modal schemes needing to be continually benchmarked and improved against freely evolving sectional schemes and observations.

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