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 Aerosol–radiation interaction modelling using online coupling between the WRF 3.7.1 meteorological model and the CHIMERE 2016 chemistry-transport model, through the OASIS3-MCT coupler

2017 ◽  
Vol 10 (2) ◽  
pp. 927-944 ◽  
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 regional chemistry-transport models are usually driven by a distinct meteorological model or data. 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–radiation interactions. The WRF-CHIMERE online model has a higher computational burden than both models run 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 computation 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, the Middle East and western Asia during the summer of 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. The 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 in both AOD and PM10 concentrations.

scholarly journals WRF-Chem simulations of a typical pre-monsoon dust storm in northern India: influences on aerosol optical properties and radiation budget

2014 ◽  
Vol 14 (5) ◽  
pp. 2431-2446 ◽  
Author(s):  
R. Kumar ◽  
M. C. Barth ◽  
G. G. Pfister ◽  
M. Naja ◽  
G. P. Brasseur
Keyword(s):  
Optical Properties ◽  
Dust Storm ◽  
Regional Scale ◽  
Radiation Budget ◽  
Dust Particles ◽  
Storm Event ◽  
Aerosol Optical Properties ◽  
Northern India ◽  
Dust Storm Event ◽  
The Impact

Abstract. The impact of a typical pre-monsoon season (April–June) dust storm event on the regional aerosol optical properties and radiation budget in northern India is analyzed. The dust storm event lasted from 17 to 22 April 2010 and the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) estimated total dust emissions of 7.5 Tg over the model domain. Both in situ (AERONET – Aerosol Robotic Network) and satellite observations show significant increase (> 50%) in local to regional scale aerosol optical depth (AOD) and decrease (> 70%) in the Ångström exponent (α) during this period. Amongst the AERONET sites in this region, Kanpur was influenced the most, where the AOD reached up to 2.1 and the α decreased to −0.09 during the dust storm period. The WRF-Chem model reproduced the spatial and temporal distributions of dust plumes and aerosol optical properties but generally underestimated the AOD. The average MODIS and WRF-Chem AOD (550 nm) values in a subregion (70–80° E, 25–30° N) affected the most by the dust storm are estimated as 0.80 ± 0.30 and 0.68 ± 0.28, respectively. Model results show that dust particles cool the surface and the top of the atmosphere, but warm the atmosphere itself. The radiative perturbation due to dust aerosols averaged over the subregion is estimated as −2.9 ± 3.1 W m−2 at the top of the atmosphere, 5.1 ± 3.3 W m−2 in the atmosphere and −8.0 ± 3.3 W m−2 at the surface. The simulated instantaneous cooling under the dust plume was much higher and reached −227 and −70 W m−2 at the surface and the top of the atmosphere, respectively. The impact of these radiative perturbations on the surface energy budget is estimated to be small on a regional scale but significant locally.

scholarly journals WRF-Chem simulations of a typical pre-monsoon dust storm in northern India: influences on aerosol optical properties and radiation budget

2013 ◽  
Vol 13 (8) ◽  
pp. 21837-21881 ◽  
Author(s):  
R. Kumar ◽  
M. C. Barth ◽  
G. G. Pfister ◽  
M. Naja ◽  
G. P. Brasseur
Keyword(s):  
Optical Properties ◽  
Dust Storm ◽  
Regional Scale ◽  
Radiation Budget ◽  
Dust Particles ◽  
Storm Event ◽  
Aerosol Optical Properties ◽  
Northern India ◽  
Dust Storm Event ◽  
The Impact

Abstract. The impact of a typical pre-monsoon season (April–June) dust storm event on the regional aerosol optical properties and radiation budget in northern India is analyzed. The dust storm event lasted from 17 to 22 April 2010 and the WRF-Chem model estimated total dust emissions of 7.5 Tg over the model domain. Both in situ (AERONET) and satellite observations show significant increase (>50%) in local to regional scale aerosol optical depth (AOD) and decrease (>70%) in the Angström exponent (α) during this period. Amongst the AERONET sites in this region, Kanpur was influenced the most where the AOD reached up to 2.1 and the α decreased to −0.09 during the dust storm period. The WRF-Chem model reproduced the spatial and temporal distributions of dust plumes and aerosol optical properties but generally underestimated the AOD. The average MODIS and WRF-Chem AOD (550 nm) values in high dust laden region are estimated as 0.80 ± 0.30 and 0.68 ± 0.28, respectively. Model results show that dust particles cool the surface and the top of the atmosphere, and warm the atmosphere. The regionally averaged radiative perturbation due to dust aerosols is estimated as −2.0 ± 3.0 W m−2 at the top of the atmosphere, 2.3 ± 1.8 W m−2 in the atmosphere and −4.4 ± 3.1 W m−2 at the surface. The impact of these radiative perturbations on the surface energy budget is estimated to be small on a regional scale but significant locally.

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 Space-based retrieval of NO<sub>2</sub> over biomass burning regions: quantifying and reducing uncertainties

2014 ◽  
Vol 7 (10) ◽  
pp. 3431-3444 ◽  
Author(s):  
N. Bousserez
Keyword(s):  
Optical Properties ◽  
Biomass Burning ◽  
Shape Factor ◽  
Transport Model ◽  
Sensitivity Analyses ◽  
The Arctic ◽  
Ozone Monitoring Instrument ◽  
Aerosol Optical Properties ◽  
Atmospheric Scattering ◽  
The Impact

Abstract. The accuracy of space-based nitrogen dioxide (NO2) retrievals from solar backscatter radiances critically depends on a priori knowledge of the vertical profiles of NO2 and aerosol optical properties. This information is used to calculate an air mass factor (AMF), which accounts for atmospheric scattering and is used to convert the measured line-of-sight "slant" columns into vertical columns. In this study we investigate the impact of biomass burning emissions on the AMF in order to quantify NO2 retrieval errors in the Ozone Monitoring Instrument (OMI) products over these sources. Sensitivity analyses are conducted using the Linearized Discrete Ordinate Radiative Transfer (LIDORT) model. The NO2 and aerosol profiles are obtained from a 3-D chemistry-transport model (GEOS-Chem), which uses the Fire Locating and Monitoring of Burning Emissions (FLAMBE) daily biomass burning emission inventory. Aircraft in situ data collected during two field campaigns, the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) and the Dust and Biomass-burning Experiment (DABEX), are used to evaluate the modeled aerosol optical properties and NO2 profiles over Canadian boreal fires and West African savanna fires, respectively. Over both domains, the effect of biomass burning emissions on the AMF through the modified NO2 shape factor can be as high as −60%. A sensitivity analysis also revealed that the effect of aerosol and shape factor perturbations on the AMF is very sensitive to surface reflectance and clouds. As an illustration, the aerosol correction can range from −20 to +100% for different surface reflectances, while the shape factor correction varies from −70 to −20%. Although previous studies have shown that in clear-sky conditions the effect of aerosols on the AMF was in part implicitly accounted for by the modified cloud parameters, here it is suggested that when clouds are present above a surface layer of scattering aerosols, an explicit aerosol correction would be beneficial to the NO2 retrieval. Finally, a new method that uses slant column information to correct for shape-factor-related AMF error over NOx emission sources is proposed, with possible application to near-real-time OMI retrievals.

scholarly journals Influence of aquifer and streambed heterogeneity on the distribution of groundwater discharge

2009 ◽  
Vol 13 (1) ◽  
pp. 69-77 ◽  
Author(s):  
E. Kalbus ◽  
C. Schmidt ◽  
J. W. Molson ◽  
F. Reinstorf ◽  
M. Schirmer
Keyword(s):  
Groundwater Flow ◽  
Transport Model ◽  
Regional Scale ◽  
Base Case ◽  
Case Scenario ◽  
Base Case Scenario ◽  
Heterogeneous Distribution ◽  
Heterogeneous Aquifer ◽  
The Impact ◽  
Low K

Abstract. The spatial distribution of groundwater fluxes through a streambed can be highly variable, most often resulting from a heterogeneous distribution of aquifer and streambed permeabilities along the flow pathways. Using a groundwater flow and heat transport model, we defined four scenarios of aquifer and streambed permeability distributions to simulate and assess the impact of subsurface heterogeneity on the distribution of groundwater fluxes through the streambed: (a) a homogeneous low-K streambed within a heterogeneous aquifer; (b) a heterogeneous streambed within a homogeneous aquifer; (c) a well connected heterogeneous low-K streambed within a heterogeneous aquifer; and (d) a poorly connected heterogeneous low-K streambed within a heterogeneous aquifer. The simulation results were compared with a base case scenario, in which the streambed had the same properties as the aquifer, and with observed data. The results indicated that the aquifer has a stronger influence on the distribution of groundwater fluxes through the streambed than the streambed itself. However, a homogeneous low-K streambed, a case often implemented in regional-scale groundwater flow models, resulted in a strong homogenization of fluxes, which may have important implications for the estimation of peak mass flows. The flux distributions simulated with heterogeneous low-K streambeds were similar to the flux distributions of the base case scenario, despite the lower permeability. The representation of heterogeneous distributions of aquifer and streambed properties in the model has been proven to be beneficial for the accuracy of flow simulations.

scholarly journals Simulation of Atmospheric Circulation over Tahiti and of Local Effects on the Transport of 210Pb

2009 ◽  
Vol 137 (6) ◽  
pp. 1863-1880 ◽  
Author(s):  
P. Heinrich ◽  
X. Blanchard
Keyword(s):  
Atmospheric Circulation ◽  
General Circulation ◽  
Transport Model ◽  
Mesoscale Model ◽  
Natural Radionuclide ◽  
Circulation Model ◽  
Spatial And Temporal Variability ◽  
Local Circulation ◽  
Meteorological Model ◽  
The Impact

Abstract Atmospheric transport of the natural radionuclide 210Pb is simulated by a general circulation model (GCM) and calculated surface concentrations are compared with those recorded at the Tahiti station on a daily scale. Numerical results for 2006 show the underestimation of concentrations for most recorded peaks. The purpose of this paper is to explain the observed discrepancies, to evaluate the GCM physical parameterizations, and to determine by numerical means the concentrations at Tahiti for a pollutant circulating across the South Pacific Ocean. Three meteorological situations in 2006 are further analyzed. Circulation over Tahiti for these periods is simulated by a mesoscale meteorological model using four nested grids with resolutions ranging from 27 to 1 km. The calculated wind fields are validated by those observed at two stations on the northwest coast of Tahiti, which is exposed both to topography-induced vortices and to thermally driven local breezes. Atmospheric dispersion of an offshore plume is then calculated by a particle Lagrangian transport model, driven by the mesoscale model at 1- and 81-km resolutions, representing local and global circulations, respectively. Simulations at 1-km resolution show the complex atmospheric circulation over Tahiti, which results in a large spatial and temporal variability of 210Pb surface concentrations on an hourly scale. The impact of local circulation is, however, limited when daily averaged concentrations at the station are considered. Under the studied regimes, transport simulations at the two resolutions lead to similar daily averaged concentrations. The deficiencies of the GCM in simulating daily averaged 210Pb concentrations could be attributable to the deep convection parameterization.

scholarly journals Simulating Secondary Inorganic Aerosols using the chemistry transport model MOCAGE version R2.15.0

2015 ◽  
Vol 8 (4) ◽  
pp. 3593-3651 ◽  
Author(s):  
J. Guth ◽  
B. Josse ◽  
V. Marécal ◽  
M. Joly
Keyword(s):  
North America ◽  
Transport Model ◽  
Regional Scale ◽  
In Situ Measurements ◽  
Aerosol Composition ◽  
Chemistry Transport Model ◽  
Inorganic Aerosols ◽  
Modis Aod ◽  
Inorganic Aerosol

Abstract. In this study we develop a Secondary Inorganic Aerosol (SIA) module for the chemistry transport model MOCAGE developed at CNRM. Based on the thermodynamic equilibrium module ISORROPIA II, the new version of the model is evaluated both at the global scale and at the regional scale. The results show high concentrations of secondary inorganic aerosols in the most polluted regions being Europe, Asia and the eastern part of North America. Asia shows higher sulfate concentrations than other regions thanks to emissions reduction in Europe and North America. Using two simulations, one with and the other without secondary inorganic aerosol formation, the model global outputs are compared to previous studies, to MODIS AOD retrievals, and also to in situ measurements from the HTAP database. The model shows a better agreement in all geographical regions with MODIS AOD retrievals when introducing SIA. It also provides a good statistical agreement with in situ measurements of secondary inorganic aerosol composition: sulfate, nitrate and ammonium. In addition, the simulation with SIA gives generally a better agreement for secondary inorganic aerosols precursors (nitric acid, sulfur dioxide, ammonia) in particular with a reduction of the Modified Normalised Mean Bias (MNMB). At the regional scale, over Europe, the model simulation with SIA are compared to the in situ measurements from the EMEP database and shows a good agreement with secondary inorganic aerosol composition. The results at the regional scale are consistent with those obtained with the global simulations. The AIRBASE database was used to compare the model to regulated air quality pollutants being particulate matter, ozone and nitrogen dioxide concentrations. The introduction of the SIA in MOCAGE provides a reduction of the PM2.5 MNMB of 0.44 on a yearly basis and even 0.52 on a three spring months period (March, April, May) when SIA are maximum.

scholarly journals The influence of biogenic emissions on upper-tropospheric methanol as revealed from space

2007 ◽  
Vol 7 (24) ◽  
pp. 6119-6129 ◽  
Author(s):  
G. Dufour ◽  
S. Szopa ◽  
D. A. Hauglustaine ◽  
C. D. Boone ◽  
C. P. Rinsland ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Biomass Burning ◽  
Transport Model ◽  
Tropospheric Chemistry ◽  
Biogenic Emissions ◽  
Chemistry Transport Model ◽  
Mixing Ratios ◽  
Oxygenated Compounds ◽  
Global Space ◽  
The Impact

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.

High resolution Aerosol Radiative Effects over Europe using detailed optical properties from the Chemical Transport Model PMCAMx

2020 ◽  
Author(s):  
Marios Bruno Korras Carraca ◽  
Dimitris Manetas ◽  
David Patoulias ◽  
Spyros Pandis ◽  
Nikolaos Hatzianastassiou ◽  
...  
Keyword(s):  
Optical Properties ◽  
Temporal Resolution ◽  
Biomass Burning ◽  
Transport Model ◽  
Aerosol Particles ◽  
Chemical Transport ◽  
Chemical Transport Model ◽  
Aerosol Optical Properties ◽  
The Earth ◽  
Spatio Temporal

&lt;p&gt;Natural and anthropogenic aerosol particles are major drivers of the Earth&amp;#8217;s radiation budget, which they affect directly (through scattering and absorption) and indirectly (through modification of cloud scattering and precipitation properties), while they semi-directly influence atmospheric stability and convection, mainly through modification of solar radiation absorption by the atmosphere. Despite the important climatic role of aerosols, large uncertainties in their radiative effects remain due to limited knowledge of the aerosol spatio-temporal distribution and physico-chemical properties. The interaction of aerosols with radiation is strongly dependent on their optical properties, which in turn are controlled by the particles&amp;#8217; size distribution, shape, chemical composition and mixing state. In order to accurately estimate the magnitude of the aerosol direct radiative effect (DRE), detailed knowledge of their optical properties with high spatial and temporal resolution is required.&lt;/p&gt;&lt;p&gt;The European continent is a region of particular interest for studying atmospheric aerosol effects, because of the presence of&amp;#160; numerous and varying sources of particles and their precursors, such as industries, large urban centers and biomass burning, especially when combined with high levels of solar insolation during summer. In this study, the aerosol DRE over Europe is examined using the FORTH deterministic spectral radiative transfer model (RTM) and aerosol data from the chemical transport model PMCAMx. Chemically and size resolved aerosol concentrations predicted by PMCAMx are combined with a Mie model to calculate key aerosol optical properties (i.e. vertically resolved aerosol optical depth, single scattering albedo and asymmetry parameter) that are necessary to compute aerosol DRE using the RTM. The Mie model takes into account concentrations of organics, black carbon, sulfate, nitrate, ammonium, chlorine, sodium, water, and crustal material, and calculates aerosol optical properties assuming that the aerosol particles of the same size are internally mixed. The DRE is estimated at the Earth&amp;#8217;s surface, within the atmospheric column and at the top of the atmosphere (TOA), at high spatial and temporal resolution (36 &amp;#215; 36 km grids, 27 vertical layers, hourly), during June and July 2012.&lt;/p&gt;&lt;p&gt;Initial modelling results reveal that DREs exhibit significant spatio-temporal variability, due to the heterogeneity of source emissions rates, mostly with regard to wildfires, and the varying synoptic conditions. Emphasis is thus given to biomass burning aerosols, which are among the most significant radiative forcing agents in Europe during summer. Their relative forcing is computed by performing model computations with and without biomass burning emissions.&lt;/p&gt;

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