Development and application of a reactive plume-in-grid model: evaluation over greater Paris 13 t h Harmo Conference Irène Korsakissok 1 , 2 , Vivien Mallet 1 , 3 1 CEREA, joint laboratory ENPC/EDF R&D, Paris-Est university, France 2 IRSN, Fontenay-aux-roses, France 3 INRIA, Paris-Rocquencourt research center, France 1-4 June 2010 - Paris I. Korsakissok (CEREA/IRSN) 1-4 June 2010 1 / 18
Subgrid-scale modeling of emissions Outline Subgrid-scale modeling of emissions 1 Why use a subgrid model ? Model coupling Non-linear chemistry Application over Greater Paris 2 Conclusions 3 I. Korsakissok (CEREA/IRSN) 1-4 June 2010 2 / 18
Subgrid-scale modeling of emissions Why use a subgrid model ? A wide range of scales From µ m (particles) to km (meteo) Gridded representation : usually from 1 to 50 km... Subgrid-scale phenomena : emissions, chemistry, clouds, land use, turbulence... global scale continental scale local scale regional scale I. Korsakissok (CEREA/IRSN) 1-4 June 2010 3 / 18
Subgrid-scale modeling of emissions Model coupling Model coupling within Polyphemus platform Using Polyphemus modeling platform : modularity, easy coupling Plume-in-grid method : coupling an Eulerian model (Polair3D) and a Gaussian puff model to model point source emissions Puffs are “injected” into the Eulerian model after a given time (“injection time”) Puff location, Puff transfer puff size Eulerian Plume-in- Puff Model grid Model interface Meteorological Meteorological data (wind, stability) data in puff cell Eulerian concentrations Gaussian concentrations Saved concentrations: Eulerian + Gaussian I. Korsakissok (CEREA/IRSN) 1-4 June 2010 4 / 18
Subgrid-scale modeling of emissions Model coupling Model coupling within Polyphemus platform Puffs size given by standard deviations σ x , σ y , σ z (similarity theory, Briggs) Gaussian plume model real plume ∆ t puff time step between two 2 σ y 2 σ z t inj : puffs’ emissions 2 σ x injection in Wind u the Eulerian t inj injection time (puff “lifetime”) model u Δ t puff Gaussian puff model t inj ∆ t puff : total number of puffs handled by the model for one continous source Reference : Korsakissok, I. et Mallet, V. (2010). Subgrid-scale treatment for major point sources in an Eulerian model : A sensitivity study on the European Tracer Experiment (ETEX) and Chernobyl cases. Journal of Geophysical Research. 115 :D03303. I. Korsakissok (CEREA/IRSN) 1-4 June 2010 4 / 18
Subgrid-scale modeling of emissions Non-linear chemistry Reactive plume-in-grid model Phase 3: full chemistry acid and ozone production Advantages of subgrid model Phase 1: photostationary state NO/NO2/O3 Better representation of local-scale diffusion Source height and plume rise Phase 2: acid formation through OH and NO3 Near-source chemistry Chemistry within puffs The species in one puff α react with each other The species in two overlapping puffs α and β react V α V αβ with each other V β The species in one puff react with the background species (from the Eulerian model) I. Korsakissok (CEREA/IRSN) 1-4 June 2010 5 / 18
Subgrid-scale modeling of emissions Non-linear chemistry Chemistry between puffs and background species A + c b d ( c α A ) + c b A c b A c b B c b = − k ( c α A c α + c α B + c α ) k B B A A + B → P d t − � �� � � �� � � �� � puff background interaction A , c α B puff c α d c b A − kc b A c b = background chemistry (Eulerian) c b A , c b B d t B background � � A + c b − d c b d c α d c α A A A = puff=background perturbation d t d t d t ozone titration x1e+10 8 NO2 mass NO mass plume mass (micrograms) 6 k O3 mass O 3 + NO → NO 2 + O 2 − 4 2 0 plume of NO x (NO+NO 2 ) -2 uniform background of O 3 -4 -6 0 10 20 30 40 50 60 70 → Decrease of in-plume O 3 Time after emission (minutes) Evolution of in-plume mass for several species ( µ g) in a concentration continuous plume of NO x emitted within a background of O 3 . I. Korsakissok (CEREA/IRSN) 1-4 June 2010 6 / 18
Application over Greater Paris Outline Subgrid-scale modeling of emissions 1 Application over Greater Paris 2 Spatial impact of subgrid-scale modeling Results on measurement stations Sensitivity study Conclusions 3 I. Korsakissok (CEREA/IRSN) 1-4 June 2010 7 / 18
Application over Greater Paris Issues What is the impact of a subgrid-scale modeling of point emissions on 1 regional photochemistry ? Impact on primary vs secondary species ? 2 Impact on results over six months vs particular days ? 3 Sensitivity to local-scale modeling ? 4 Reference : Korsakissok, I. et Mallet, V. (2010). Development and application of a reactive plume-in-grid model : Evaluation over Greater Paris. Atmospheric Chemistry and Physics Discussions 10, 5091-5134 I. Korsakissok (CEREA/IRSN) 1-4 June 2010 8 / 18
Application over Greater Paris Application over Greater Paris s15 s24 s24 s25 s25 s23 s23 s32 Point sources ( ) and measurement stations (rural and urban ). Left : SO 2 , right : NO. The circle diameters are proportional to the sources emission rates. Ile-de-France (Paris region), summer 2001, six months Meteorological fields from ECMWF (0 . 36 ◦ resolution) Full gaseous chemistry (RACM mechanism) Polair3D (0 . 05 ◦ resolution) with/without subgrid modeling (similarity theory, t inj = 20 min, ∆ t puff = 100 s) 89 point sources : Q s > 10 6 µ g s − 1 for NO x (20 % of total emissions) or SO 2 (55 % of total emissions) I. Korsakissok (CEREA/IRSN) 1-4 June 2010 9 / 18
Application over Greater Paris Spatial impact of subgrid-scale modeling Spatial impact of subgrid-scale modeling 49.2 49.2 49.0 49.0 48.8 48.8 48.6 48.6 48.4 48.4 48.2 48.2 1.5 2.0 2.5 3.0 3.5 1.5 2.0 2.5 3.0 3.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 NO 2 SO 2 49.2 49.2 49.0 49.0 48.8 48.8 48.6 48.6 48.4 48.4 48.2 48.2 1.5 2.0 2.5 3.0 3.5 1.5 2.0 2.5 3.0 3.5 -4.0 -3.5 -3.0 -2.5 -2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 O 3 NO Differences in mean ground concentrations : Polair3D - plume-in-grid. Concentrations averaged over six months ( µ g m − 3 ). I. Korsakissok (CEREA/IRSN) 1-4 June 2010 10 / 18
Application over Greater Paris Spatial impact of subgrid-scale modeling Spatial impact of subgrid-scale modeling during a low-dispersion day (sulfur dioxide) -20.1 -17.6 -15.1 -12.6 -10.1-7.6 -5.1 -2.6 -0.1 2.4 4.9 7.5 10.0 12.5 15.0 17.520.0 22.5 25.0 Differences in hourly-averaged SO 2 ground concentrations : Polair3D - plume-in-grid ( µ g m − 3 ), for day 2001-08-24 between 03 and 15h (local hour). I. Korsakissok (CEREA/IRSN) 1-4 June 2010 11 / 18
Application over Greater Paris Spatial impact of subgrid-scale modeling Spatial impact of subgrid-scale modeling during a low-dispersion day (ozone) -12.9 -12.0 -11.1 -10.1-9.2 -8.2 -7.3 -6.4 -5.4 -4.5 -3.5 -2.6 -1.6 -0.7 0.2 1.2 2.1 3.1 4.0 Differences in hourly-averaged O 3 ground concentrations : Polair3D - plume-in-grid ( µ g m − 3 ), for day 2001-08-20 between 03 and 15h (local hour). I. Korsakissok (CEREA/IRSN) 1-4 June 2010 12 / 18
Application over Greater Paris Results on measurement stations Results on stations for SO 2 and NO 25 6.2% v -15.0% n t 1 u -10.3% u X ( x i − y i ) 2 , RMSE = 20 -6.2% -8.4% -11.6% -13.1% n i = 1 -8.1% -11.8% -12.5% -9.4% -13.6% -8.9% -16.2% 15 -17.4% -12.2% -0.8% with x i simulated values, -14.2% -10.7% 10 y i observed values. 5 SO 2 – Mean observed values : 6 . 2 µ g m − 3 Polair3D, -4.2% plume-in-grid -5.9% -4.4% -3.3% 50 -5.0% -4.1% -5.2% Black % : urban -4.6% -3.2% -4.9% -4.5% -6.9% 40 -2.8% -3.6% -4.5% -4.1% stations -3.0% -1.3% -6.1% -5.0% 30 Green % : -0.3% -6.7% -2.2% 20 periurban and 10 rural stations. NO – Mean observed values : 10 . 42 µ g m − 3 Comparison to observations on measurement stations, over six months. Mean and RMSE in µ g m − 3 . I. Korsakissok (CEREA/IRSN) 1-4 June 2010 13 / 18
Application over Greater Paris Results on measurement stations Results on stations for SO 2 and NO 25 6.2% v n -15.0% t 1 u -10.3% u X ( x i − y i ) 2 , RMSE = -6.2% -8.4% 20 -11.6% n -13.1% i = 1 -11.8% -8.1% -12.5% -9.4% -13.6% -8.9% -16.2% 15 -17.4% -0.8% -12.2% with x i simulated values, -14.2% -10.7% 10 y i observed values. 5 SO 2 – Point sources : 55% of total emissions Polair3D, -4.2% plume-in-grid -5.9% -4.4% -3.3% 50 -5.0% -5.2% Black % : urban -4.1% -4.6% -3.2% -4.9% -4.5% -6.9% 40 -2.8% -4.5% -3.6% -4.1% stations -3.0% -1.3% -6.1% -5.0% 30 Green % : -0.3% -6.7% -2.2% 20 periurban and 10 rural stations. NO – Point sources : 20% of total emissions SO 2 more impacted (more point sources) than NO, urban/rural stations equally impacted I. Korsakissok (CEREA/IRSN) 1-4 June 2010 13 / 18
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