scholarly journals Modelling the mineralogical composition and solubility of mineral dust in the Mediterranean area with CHIMERE 2017r4

2020 ◽  
Author(s):  
Laurent Menut ◽  
Guillaume Siour ◽  
Bertrand Bessagnet ◽  
Florian Couvidat ◽  
Emilie Journet ◽  
...  
Keyword(s):  
Optical Properties ◽  
Transport Model ◽  
Mineral Dust ◽  
Mineralogical Composition ◽  
Mediterranean Area ◽  
Mineral Species ◽  
Chemistry Transport Model ◽  
Deposition Fluxes ◽  
Global Databases ◽  
Radiative Impact

Abstract. Modelling of mineral dust is often done using one single mean species. But for biogeochemical studies, it could be useful to access to a more detailed information on differenciated mineral species and the associated chemical composition. The fact to differentiate mineral species would also induce different optical properties and densities, then different radiative impact, transport and deposition. In this study, the mineralogical differenciation in implemented in the CHIMERE regional chemistry-transport model, by using global databases. The results show that this implementation does not change a lot the results in term of Aerosol Optical Depth, surface concentrations and deposition fluxes. But the information on mineralogy, with a high spatial (a few kilometers) and temporal (one hour) resolution, is now available and is ready to be used for future biogeochemical studies.

scholarly journals Modelling the mineralogical composition and solubility of mineral dust in the Mediterranean area with CHIMERE 2017r4

2020 ◽  
Vol 13 (4) ◽  
pp. 2051-2071 ◽  
Author(s):  
Laurent Menut ◽  
Guillaume Siour ◽  
Bertrand Bessagnet ◽  
Florian Couvidat ◽  
Emilie Journet ◽  
...  
Keyword(s):  
Optical Properties ◽  
Transport Model ◽  
Mineral Dust ◽  
Mineralogical Composition ◽  
Mediterranean Area ◽  
Mineral Species ◽  
Chemistry Transport Model ◽  
Deposition Fluxes ◽  
Global Databases ◽  
Radiative Impact

Abstract. Modelling of mineral dust is often done using one single mean species. But for biogeochemical studies, it could be useful to access to a more detailed information on differentiated mineral species and the associated chemical composition. Differentiating between mineral species would also induce different optical properties and densities and then different radiative impact, transport and deposition. In this study, the mineralogical differentiation is implemented in the CHIMERE regional chemistry-transport model, by using global databases. The results show that this implementation does not change the results much in terms of aerosol optical depth, surface concentrations and deposition fluxes. But the information on mineralogy, with a high spatial (a few kilometres) and temporal (1 h) resolution, is now available and is ready to be used for future biogeochemical studies.

scholarly journals Analysis of the atmospheric composition during the summer 2013 over the Mediterranean area using the CHARMEX measurements and the CHIMERE model

2014 ◽  
Vol 14 (16) ◽  
pp. 23075-23123 ◽  
Author(s):  
L. Menut ◽  
S. Mailler ◽  
G. Siour ◽  
B. Bessagnet ◽  
S. Turquety ◽  
...  
Keyword(s):  
Transport Model ◽  
Mineral Dust ◽  
Mediterranean Area ◽  
Western Mediterranean ◽  
Atmospheric Composition ◽  
Chemistry Transport Model ◽  
Dust Emissions ◽  
Adequate Representation ◽  
The Mediterranean ◽  
Local Dust

Abstract. The ADRIMED campaign provides measurements of all key parameters regarding atmospheric composition in the Mediterranean area during the summer 2013. This is an opportunity to quantify the ability of current models to adequately represent the atmospheric composition in this complex region, which is influenced by anthropogenic emissions from Europe, Africa, the Middle-East and from shipping activities as well as mineral dust emissions mostly from the arid areas in Africa, sea-salt emissions, biomass burning emissions and biogenic emissions from the vegetation. The CHIMERE model in its present version is a chemistry-transport model which takes into account all these processes. We show here by simulating the period from 5 June to 15 July 2013 with the CHIMERE model and comparing the results to both routine and specific ADRIMED measurements that this model allows an adequate representation the atmospheric composition over the western Mediterranean, in terms of ozone concentration, particulate matter (PM) and aerosol optical depth (AOD). It is also shown that the concentrations of PM on all the considered area is dominated by mineral dust, even though local dust emissions in Europe are certainly overestimated by the model. A comparison with sulphate concentrations at Cape Corsica exhibits some discrepancies related to the regridding of shipping emissions.

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

Solar Energy ◽  
2018 ◽  
Vol 176 ◽  
pp. 439-452 ◽  
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

scholarly journals Influence of light-absorbing particles on snow spectral irradiance profiles

2019 ◽  
Vol 13 (8) ◽  
pp. 2169-2187 ◽  
Author(s):  
Francois Tuzet ◽  
Marie Dumont ◽  
Laurent Arnaud ◽  
Didier Voisin ◽  
Maxim Lamare ◽  
...  
Keyword(s):  
Optical Properties ◽  
Radiative Transfer ◽  
Black Carbon ◽  
Mineral Dust ◽  
Surface Energy Budget ◽  
Spectral Irradiance ◽  
Light Extinction ◽  
Attractive Alternative ◽  
Chemical Measurements ◽  
Radiative Impact

Abstract. Light-absorbing particles (LAPs) such as black carbon or mineral dust are some of the main drivers of snow radiative transfer. Small amounts of LAPs significantly increase snowpack absorption in the visible wavelengths where ice absorption is particularly weak, impacting the surface energy budget of snow-covered areas. However, linking measurements of LAP concentration in snow to their actual radiative impact is a challenging issue which is not fully resolved. In the present paper, we point out a new method based on spectral irradiance profile (SIP) measurements which makes it possible to identify the radiative impact of LAPs on visible light extinction in homogeneous layers of the snowpack. From this impact on light extinction it is possible to infer LAP concentrations present in each layer using radiative transfer theory. This study relies on a unique dataset composed of 26 spectral irradiance profile measurements in the wavelength range 350–950 nm with concomitant profile measurements of snow physical properties and LAP concentrations, collected in the Alps over two snow seasons in winter and spring conditions. For 55 homogeneous snow layers identified in our dataset, the concentrations retrieved from SIP measurements are compared to chemical measurements of LAP concentrations. A good correlation is observed for measured concentrations higher than 5 ng g−1 (r2=0.81) despite a clear positive bias. The potential causes of this bias are discussed, underlining a strong sensitivity of our method to LAP optical properties and to the relationship between snow microstructure and snow optical properties used in the theory. Additional uncertainties such as artefacts in the measurement technique for SIP and chemical contents along with LAP absorption efficiency may explain part of this bias. In addition, spectral information on LAP absorption can be retrieved from SIP measurements. We show that for layers containing a unique absorber, this absorber can be identified in some cases (e.g. mineral dust vs. black carbon). We also observe an enhancement of light absorption between 350 and 650 nm in the presence of liquid water in the snowpack, which is discussed but not fully elucidated. A single SIP acquisition lasts approximately 1 min and is hence much faster than collecting a profile of chemical measurements. With the recent advances in modelling LAP–snow interactions, our method could become an attractive alternative to estimate vertical profiles of LAP concentrations in snow.

scholarly journals The influence of dust optical properties on the colour of simulated MSG-SEVIRI Desert Dust infrared imagery

2018 ◽  
Vol 18 (13) ◽  
pp. 9681-9703 ◽  
Author(s):  
Jamie R. Banks ◽  
Kerstin Schepanski ◽  
Bernd Heinold ◽  
Anja Hünerbein ◽  
Helen E. Brindley
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Particle Shape ◽  
Transport Model ◽  
Mineral Dust ◽  
Spherical Particles ◽  
Upper And Lower Bounds ◽  
Infrared Imagery ◽  
Desert Dust ◽  
Infrared Extinction

Abstract. Satellite imagery of atmospheric mineral dust is sensitive to the optical properties of the dust, governed by the mineral refractive indices, particle size, and particle shape. In infrared channels the imagery is also sensitive to the dust layer height and to the surface and atmospheric environment. Simulations of mineral dust in infrared Desert Dust imagery from the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) have been performed, using the COSMO-MUSCAT (COSMO: COnsortium for Small-scale MOdelling; MUSCAT: MUltiScale Chemistry Aerosol Transport Model) dust transport model and the Radiative Transfer for TOVS (RTTOV) program, in order to investigate the sensitivity of the imagery to assumed dust properties. This paper introduces the technique and performs initial validation and comparisons with SEVIRI measurements over North Africa for daytime hours during 6 months covering June and July of 2011–2013. Using T-matrix scattering theory and assuming the dust particles to be spherical or spheroidal, wavelength- and size-dependent dust extinction values are calculated for a number of different dust refractive index databases, along with several values of the particle aspect ratio, denoting the particle shape. The consequences for the infrared extinction values of both the particle shape and the particle orientation are explored: this analysis shows that as the particle asphericity increases, the extinctions increase if the particles are aligned horizontally, and decrease if they are aligned vertically. Randomly oriented spheroidal particles have very similar infrared extinction properties as spherical particles, whereas the horizontally and vertically aligned particles can be considered to be the upper and lower bounds on the extinction values. Inputting these values into COSMO-MUSCAT-RTTOV, it is found that spherical particles do not appear to be sufficient to describe fully the resultant colour of the dust in the infrared imagery. Comparisons of SEVIRI and simulation colours indicate that of the dust types tested, the dust refractive index dataset produced by Volz (1973) shows the most similarity in the colour response to dust in the SEVIRI imagery, although the simulations have a smaller range of colour than do the observations. It is also found that the thermal imagery is most sensitive to intermediately sized particles (radii between 0.9 and 2.6 µm): larger particles are present in too small a concentration in the simulations, as well as with insufficient contrast in extinction between wavelength channels, to have much ability to perturb the resultant colour in the SEVIRI dust imagery.

scholarly journals Response of secondary inorganic aerosol concentrations and deposition fluxes of S and N across Germany to emission changes during high PM<sub>10</sub> episodes in spring 2009

2013 ◽  
Vol 13 (6) ◽  
pp. 15783-15827 ◽  
Author(s):  
S. Banzhaf ◽  
M. Schaap ◽  
R. J. Wichink Kruit ◽  
H. A. C. Denier van der Gon ◽  
R. Stern ◽  
...  
Keyword(s):  
Western Europe ◽  
Transport Model ◽  
N Deposition ◽  
Chemistry Transport Model ◽  
Deposition Fluxes ◽  
Nh3 Emission ◽  
Non Linear ◽  
Inorganic Aerosol ◽  
Emission Changes ◽  
North Western

Abstract. In this study, the response of secondary inorganic aerosol (SIA) concentrations to changes in precursor emissions during high PM10 episodes over Central Europe in spring 2009 was investigated with the Eulerian Chemistry Transport Model (CTM) REM-Calgrid (RCG). The model performed well in capturing the temporal variation of PM10 and SIA concentrations and was used to analyse the different origin, development and characteristics of the selected high PM10 episodes. SIA concentrations, which attribute to about 50% of the PM10 concentration in north-western Europe, have been studied by means of several emission scenarios varying SO2, NOx and NH3 emissions within a domain covering Germany and within a domain covering Europe. It was confirmed that the response of sulphate, nitrate and ammonium concentrations and deposition fluxes of S and N to SO2, NOx and NH3 emission changes is non-linear. The deviation from linearity was found to be lower for total deposition fluxes of S and N than for SIA concentrations. Furthermore, the study has shown that incorporating explicit cloud chemistry in the model adds non-linear responses to the system and significantly modifies the response of modelled SIA concentrations and S and N deposition fluxes to changes in precursor emissions. The analysis of emission reduction scenarios demonstrates that next to European wide emission reductions additional national NH3 measures in Germany are more effective in reducing SIA concentrations and deposition fluxes than additional national measures on SO2 and NOx.

scholarly journals Optical properties and mineralogical composition of different Saharan mineral dust samples: a laboratory study

2006 ◽  
Vol 6 (2) ◽  
pp. 2897-2922 ◽  
Author(s):  
C. Linke ◽  
O. Möhler ◽  
A. Veres ◽  
Á. Mohácsi ◽  
Z. Bozóki ◽  
...  
Keyword(s):  
Optical Properties ◽  
Cross Sections ◽  
Mineral Dust ◽  
Mineralogical Composition ◽  
Dust Sample ◽  
Single Scattering ◽  
Saharan Dust ◽  
Multi Wavelength ◽  
Oxide Phases ◽  
Aerosol Chamber

Abstract. In aerosol chamber experiments optical properties of airborne mineral dust samples of defined size distribution were measured. Extinction coefficients (bext) and mass specific extinction cross sections (σext) were determined for Saharan dust samples from different locations. The results for σext were not very sensitive to the type of dust and varied at λ=550 nm between 3.3±0.4 m2 g−1 and 3.7±0.4 m2 g−1. The absorption coefficients (babs) and mass specific absorption cross sections (σabs) were determined with a novel multi-wavelength photo-acoustic absorption spectrometer (PAS). Between λ=266 nm and λ=1064 nm the derived single scattering albedos (SSA) ranged from 0.63±0.04 to 0.99±0.01. Additionally the chemical and mineralogical composition of the dust samples was analysed with special regard to the iron oxide phases hematite and goethite. At λ=266 nm the mineral dust sample without any detectable iron oxides showed a significantly higher SSA compared to the sample with a hematite content of 0.6 wt-%.

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.

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