scholarly journals The CHIMERE v2020r1 online chemistry-transport model

2021 ◽  
Author(s):  
Laurent Menut ◽  
Bertrand Bessagnet ◽  
Régis Briant ◽  
Arineh Cholakian ◽  
Florian Couvidat ◽  
...  
Keyword(s):  
Meteorological Parameters ◽  
Transport Model ◽  
Model Performance ◽  
Subgrid Scale ◽  
Chemistry Transport Model ◽  
Meteorological Model ◽  
Online Mode ◽  
Range Transport ◽  
Emission Activity ◽  
Operator Integration

Abstract. The CHIMERE v2020r1 model replaces the v2017r5 version and provides numerous novelties. The most important of which is the online coupling with the WRF meteorological model, via the OASIS3-MCT external coupler. The model can still be used in offline mode; the online mode enables taking into account the direct and indirect effects of aerosols on meteorology. This coupling also enables using the meteorological parameters with sub-hourly time-steps. Some new parameterizations are implemented to increase the model performance and the user's choices: DMS emissions, additional schemes for SOA formation with VBS and H2O, improved schemes for mineral dust, biomass burning and sea-salt emissions. The NOx emissions from lightning is added. The model also includes the possibility to use the splitting-operator integration technique. The subgrid scale variability calculation of concentrations due to emission activity sectors is now possible. Finally, a new vertical advection scheme has been implemented, able to simulate more correctly long-range transport of thin pollutants plumes.

scholarly journals An alternative way to evaluate chemistry-transport model variability

2017 ◽  
Vol 10 (3) ◽  
pp. 1199-1208 ◽  
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.

scholarly journals Representing the effects of stratosphere–troposphere exchange on 3-D O<sub>3</sub> distributions in chemistry transport models using a potential vorticity-based parameterization

2016 ◽  
Vol 16 (17) ◽  
pp. 10865-10877 ◽  
Author(s):  
Jia Xing ◽  
Rohit Mathur ◽  
Jonathan Pleim ◽  
Christian Hogrefe ◽  
Jiandong Wang ◽  
...  
Keyword(s):  
Potential Vorticity ◽  
Transport Model ◽  
Model Performance ◽  
Surface Concentration ◽  
Weather Research And Forecasting ◽  
Regional Models ◽  
Transport Models ◽  
Reference Case ◽  
Chemistry Transport Model ◽  
Spatially Varying

Abstract. Downward transport of ozone (O3) from the stratosphere can be a significant contributor to tropospheric O3 background levels. However, this process often is not well represented in current regional models. In this study, we develop a seasonally and spatially varying potential vorticity (PV)-based function to parameterize upper tropospheric and/or lower stratospheric (UTLS) O3 in a chemistry transport model. This dynamic O3–PV function is developed based on 21-year ozonesonde records from World Ozone and Ultraviolet Radiation Data Centre (WOUDC) with corresponding PV values from a 21-year Weather Research and Forecasting (WRF) simulation across the Northern Hemisphere from 1990 to 2010. The result suggests strong spatial and seasonal variations of O3 ∕ PV ratios which exhibits large values in the upper layers and in high-latitude regions, with highest values in spring and the lowest values in autumn over an annual cycle. The newly developed O3 ∕ PV function was then applied in the Community Multiscale Air Quality (CMAQ) model for an annual simulation of the year 2006. The simulated UTLS O3 agrees much better with observations in both magnitude and seasonality after the implementation of the new parameterization. Considerable impacts on surface O3 model performance were found in the comparison with observations from three observational networks, i.e., EMEP, CASTNET and WDCGG. With the new parameterization, the negative bias in spring is reduced from −20 to −15 % in the reference case to −9 to −1 %, while the positive bias in autumn is increased from 1 to 15 % in the reference case to 5 to 22 %. Therefore, the downward transport of O3 from upper layers has large impacts on surface concentration and needs to be properly represented in regional models.

Air pollution and cloud-interaction over Europe in 1985 and today

2020 ◽  
Author(s):  
Roland Schrödner ◽  
Christa Genz ◽  
Bernd Heinold ◽  
Holger Baars ◽  
Silvia Henning ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Transport Model ◽  
Cloud Droplet ◽  
Forecast Model ◽  
Sensitivity Study ◽  
High Definition ◽  
Chemistry Transport Model ◽  
Meteorological Model ◽  
Cloud Properties ◽  
Aerosol Mass

&lt;p&gt;Aerosol concentrations over Europe and Germany were simulated for the years 1985 and 2013 using the aerosol-chemistry transport model COSMO-MUSCAT. The aerosol fields from the two simulations were used in a high-resolution meteorological model for a sensitivity study on cloud properties. The modelled aerosol and cloud variables were compared to a variety of available observations, including satellites, remote sensing and in-situ observations. Finally, the radiative forcing of the aerosol could be estimated from the different sensitivity simulations.&lt;/p&gt;&lt;p&gt;Due to reduction of emissions the ambient aerosol mass and number in Europe was strongly decreased since the 1980s. Hence, today&amp;#8217;s number of particles in the CCN size range is smaller. The HD(CP)&lt;sup&gt;2&lt;/sup&gt; (High Definition Clouds and Precipitation for Climate Prediction) project amongst others aimed at analysing the effect of the emission reduction on cloud properties.&lt;/p&gt;&lt;p&gt;As a pre-requiste, the aerosol mass, number, and composition over Germany were simulated for 1985 and 2013 using the regional chemistry-transport-model COSMO-MUSCAT. The EDGAR emission inventory was used for both years.&lt;/p&gt;&lt;p&gt;The model results were compared to observations from the two HD(CP)&lt;sup&gt;2&lt;/sup&gt; campaigns that took place in 2013 (HOPE, HOPE-Melpitz) as well as the AVHRR aerosol optical thickness product, which is available from 1981 onwards. Despite the fact, that emissions of the 1980s are very uncertain, the modelled AOD is in good agreement with observations. The modelled mean CCN number concentration in 1985 is a factor of 2-4 higher than in 2013.&lt;/p&gt;&lt;p&gt;Within HD(CP)&lt;sup&gt;2&lt;/sup&gt;, the ICON weather forecast model was applied in a configuration allowing for large-eddy simulations. In these simulations, the time-varying CCN fields for the year 1985 and 2013 calculated with COSMO-MUSCAT were used as input for ICON-LEM. In the present-day simulation, the cloud droplet number agrees with observations, whereas the perturbed (1985) simulation does not with droplet numbers about twice as high as in 2013. Also, for other cloud variables systematic changes between the two scenarios were observed.&lt;/p&gt;

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

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.

scholarly journals Future climatic drivers and their effect on PM<sub>10</sub> components in Europe and the Mediterranean Sea

2019 ◽  
Vol 19 (7) ◽  
pp. 4459-4484 ◽  
Author(s):  
Arineh Cholakian ◽  
Augustin Colette ◽  
Isabelle Coll ◽  
Giancarlo Ciarelli ◽  
Matthias Beekmann
Keyword(s):  
Long Range ◽  
Transport Model ◽  
Regional Climate ◽  
Mediterranean Area ◽  
Long Range Transport ◽  
Anthropogenic Emissions ◽  
Impact Study ◽  
Chemistry Transport Model ◽  
Range Transport ◽  
The Mediterranean

Abstract. Multiple CMIP5 (Coupled Model Intercomparison Project phase 5) future scenarios run with the CHIMERE chemistry transport model (CTM) are compared to historic simulations in order to study some of the drivers governing air pollution. Here, the focus is on regional climate, anthropogenic emissions and long-range transport. Two major subdomains are explored – the European region and the Mediterranean Basin – with both areas showing high sensitivity to climate change. The Mediterranean area is explored in the context of the ChArMEx (the Chemistry Aerosol Mediterranean Experiment) project, which examines the current and future meteorological and chemical conditions of the Mediterranean area. This climate impact study covers the period from 2031 to 2100 and considers possible future scenarios in comparison with 1976 to 2005 historic simulations using three Representative Concentration Pathways (RCPs; RCP2.6, RCP4.5 and RCP8.5). A detailed analysis of total PM10 (particulate matter with a diameter smaller that 10 µm) concentrations is carried out, including the evolution of PM10 and changes to its composition. The individual effects of meteorological conditions on PM10 components are explored in these scenarios in an effort to pinpoint the meteorological parameter(s) governing each component. The anthropogenic emission impact study covers the period from 2046 to 2055 using current legislation (CLE) and maximum feasible reduction (MFR) anthropogenic emissions for the year 2050 compared with historic simulations covering the period from 1996 to 2005 and utilizing CLE2010 emissions data. Long-range transport is explored by changing the boundary conditions in the chemistry transport model over the same period as the emission impact studies. Finally, a cumulative effect analysis of these drivers is performed, and the impact of each driver on PM10 and its components is estimated. The results show that regional climate change causes a decrease in the PM10 concentrations in our scenarios (in both the European and Mediterranean subdomains), as a result of a decrease in nitrate, sulfate, ammonium and dust atmospheric concentrations in most scenarios. On the contrary, BSOA (biogenic secondary organic aerosol) displays an important increase in all scenarios, showing more pronounced concentrations for the European subdomain compared with the Mediterranean region. Regarding the relationship of different meteorological parameters to concentrations of different species, nitrate and BSOA show a strong temperature dependence, whereas sulfate is most strongly correlated with relative humidity. The temperature-dependent behavior of BSOA changes when looking at the Mediterranean subdomain, where it displays more dependence on wind speed, due to the transported nature of BSOA existing in this subdomain. A cumulative look at all drivers shows that anthropogenic emission changes overshadow changes caused by climate and long-range transport for both of the subdomains explored, with the exception of dust particles for which long-range transport changes are more influential, especially in the Mediterranean Basin. For certain species (such as sulfates and BSOA), in most of the subdomains explored, the changes caused by anthropogenic emissions are (to a certain extent) reduced by the boundary conditions and regional climate changes.

scholarly journals The effects of lightning-produced NO<sub>x</sub> and its vertical distribution on atmospheric chemistry: sensitivity simulations with MATCH-MPIC

2005 ◽  
Vol 5 (7) ◽  
pp. 1815-1834 ◽  
Author(s):  
L. J. Labrador ◽  
R. von Kuhlmann ◽  
M. G. Lawrence
Keyword(s):  
Vertical Distribution ◽  
Atmospheric Chemistry ◽  
Large Scale ◽  
Transport Model ◽  
Chemistry Transport Model ◽  
Model Match ◽  
Circulation Patterns ◽  
Range Transport ◽  
Best Fitting ◽  
The Impact

Abstract. The impact of different assumptions concerning the source magnitude as well as the vertical placement of lightning-produced nitrogen oxides is studied using the global chemistry transport model MATCH-MPIC. The responses of NOx, O3, OH, HNO3 and peroxyacetyl-nitrate (PAN) are investigated. A marked sensitivity to both parameters is found. NOx burdens globally can be enhanced by up to 100% depending on the vertical placement and source magnitude strength. In all cases, the largest enhancements occur in the tropical upper troposphere, where lifetimes of most trace gases are longer and where they thus become more susceptible to long-range transport by large-scale circulation patterns. Comparison with observations indicate that 0 and 20 Tg(N)/yr production rates of NOx from lightning are too low and too high, respectively. However, no single intermediate production rate or vertical distribution can be singled out as best fitting the observations, due to the large scatter in the datasets. This underscores the need for further measurement campaigns in key regions, such as the tropical continents.

scholarly journals Simulating CH<sub>4</sub> and CO<sub>2</sub> over South and East Asia using the zoomed chemistry transport model LMDzINCA

2017 ◽  
Author(s):  
Xin Lin ◽  
Philippe Ciais ◽  
Philippe Bousquet ◽  
Michel Ramonet ◽  
Yi Yin ◽  
...  
Keyword(s):  
East Asia ◽  
Transport Model ◽  
Model Performance ◽  
Horizontal Resolution ◽  
Surface Fluxes ◽  
Vertical Resolution ◽  
Monitoring Networks ◽  
Atmospheric Measurements ◽  
Monsoon Period ◽  
Chemistry Transport Model

Abstract. The increasing availability of atmospheric measurements of greenhouse gases (GHGs) from surface stations can improve the retrieval of their fluxes at higher spatial and temporal resolutions by inversions, provided that chemistry transport models are able to properly represent the variability of concentrations observed at different stations. South and East Asia (SEA) is a region with large and very uncertain emissions of carbon dioxide (CO2) and methane (CH4), the most potent anthropogenic GHGs. Monitoring networks have expanded greatly during the past decade in this region, which should contribute to reducing uncertainties in estimates of regional GHG budgets. In this study, we simulate concentrations of CH4 and CO2 using a zoomed version of the global chemistry transport model LMDzINCA during the period 2006–2013. The zoomed version has a fine horizontal resolution of ~ 0.66° in longitude and ~0.51° in latitude over SEA and a coarser resolution elsewhere. The concentrations of CH4 and CO2 simulated from the zoomed model (abbreviated as ‘ZASIA’) are compared to those from the same model but with a uniform regular grid of 2.50° in longitude and 1.27° in latitude (abbreviated as ‘REG’), both having the same vertical 19 sigma pressure levels and prescribed with the same biogenic and anthropogenic fluxes. Model performance is evaluated for annual gradients between sites, seasonal, synoptic and diurnal variations, against a new dataset including 30 surface stations over SEA and adjacent regions. Our results show that, when prescribed with identical surface fluxes, compared to REG, the ZASIA version moderately improves the representation of CH4 mean annual gradients between stations as well as the seasonal and synoptic variations of this trace gas within the zoomed region. This moderate improvement probably results from reduction of representation errors and a better description of the CH4 concentration gradients related to the skewed spatial distribution of surface CH4 emissions, suggesting that the zoom transport model will be better suited for inversions of CH4 fluxes in SEA. With the relatively coarse vertical resolution and low-frequency (monthly) prescribed fluxes, the model generally does not capture the diurnal cycle of CH4 at most stations even with its zoomed configuration, emphasizing the need to increase the vertical resolution, and to improve parameterizations of turbulent diffusion in the planetary boundary layer and deep convection during the monsoon period. The model performance for CH4 is better than that for CO2 at any temporal scale, likely due to inaccuracies in the CO2 fluxes prescribed in this study.

scholarly journals The effects of lightning-produced NO<sub>x</sub> and its vertical distribution on atmospheric chemistry: sensitivity simulations with MATCH-MPIC

2004 ◽  
Vol 4 (5) ◽  
pp. 6239-6281 ◽  
Author(s):  
L. J. Labrador ◽  
R. von Kuhlmann ◽  
M. G. Lawrence
Keyword(s):  
Vertical Distribution ◽  
Long Range ◽  
Atmospheric Chemistry ◽  
Transport Model ◽  
Chemistry Transport Model ◽  
Model Match ◽  
Circulation Patterns ◽  
Range Transport ◽  
Best Fitting ◽  
The Impact

Abstract. The impact of different assumptions concerning the source magnitude as well as the vertical placement of lightning-produced nitrogen oxides is studied using the global chemistry transport model MATCH-MPIC. The responses of NOx, O3, OH, HNO3 and peroxyacetyl-nitrate (PAN) are investigated. A marked sensitivity to both parameters was found. NOx burdens globally can be enhanced up to 100% depending on the vertical placement and source magnitude strength. In all cases, the largest enhancements occur in the tropical upper troposphere, where lifetimes of most trace gases are longer and where they thus become more susceptible to long-range transport by long-range circulation patterns. Comparison with observations indicate that the 0 and 20 Tg/yr(N) production rates of NOx from lightning are too low and too high a source magnitude, respectively. However, no single intermediate production rate or vertical distribution can be singled out as best fitting the observations due to the large scatter in the datasets. This underscores the need for further measurement campaigns in key regions. The vertical profiles of Pickering et al. (1998) have been implemented in MATCH-MPIC for this study.

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