Using the O 3 /NOy Ratio to Assess the O 3 -NOx-VOC Sensitivity in a Western Mediterranean Coastal Environment

Transcription

1 Using the O 3 /NOy Ratio to Assess the O 3 -NOx-VOC Sensitivity in a Western Mediterranean Coastal Environment Ariel F. Stein Centro de Estudios Ambientales del Mediterraneo (CEAM), Valencia, Spain.

2 Case 1 July 27, 1989 Castellon urban-industrial complex Western Mediterranean coast Mesometeorological Cycles of Air Pollution in the Iberian Peninsula (MECAPIP) project

3 Flight patterns (Hawker Siddeley 12 F4B ) 11:42 to 12:23 UTC 1:9 to 1: UTC

4 SO 2, NOy, and O 3 measurements 6 4 SO2 [ppb] leg2 leg3 leg4 leg leg6 leg7 leg8 SO2 [ppb] leg2 leg4 leg leg6 leg7 leg8 leg9 leg1 leg NOy [ppb] leg2 leg3 leg4 leg leg6 leg7 leg8 NOy [ppb] leg2 leg4 leg leg6 leg7 leg8 leg9 leg1 leg O3 [ppb] leg2 leg3 leg4 leg leg6 leg7 leg8 O3 [ppb] leg2 leg4 leg leg6 leg7 leg8 leg9 leg1 leg Crosswind distance [m] Crosswind distance [m]

5 O 3 vs NOy leg2 1 leg3 Morning O3 [ppb] 8 leg4 leg 6 leg NOy [ppb] leg7 leg leg2 leg4 Afternoon O3 [ppb] leg leg6 leg7 leg8 leg9 8 leg leg11 NOy [ppb]

6 Meteorological conditions Associated to an Atlantic high-pressure system, well established at mid-latitudes and extending to central Europe and the Western Mediterranean. Pollutants measured during the flights are emitted into an atmosphere relatively confined by the presence of at least one inversion layer. Wind field pattern shows a well-defined easterly circulation

7 Reactive Plume Model (RPM-IV) description Lagrangian approach to describe a horizontally segmented air parcel as it moves downwind horizontal segments, starting width 1 km Chemistry: CB-IV Emissions: local inventory (mobile, area and industrial sources) and biogenic Initial conditions: morning flight Boundary conditions: box model run w/o emissions

8 Leg 7 Leg 8 Castellón Mixed industries Powe r plant

9 Model vs. Measurements O 3 BASE NOy O 3 [ppb] leg 7 leg 8 model Minimum[ppb] Maximum[ppb] Bias (min) [ppb] Norm Bias (min) [%] Bias (max) [ppb] Norm Bias (max) [%] NOy [ppb]

10 Case 2 August 14, 2 Valencia Community Western Mediterranean coast

11 MM Mellor and Yamada PBL Anthes-Kuo cumulus One-Way nestig NATLAN, 2 land use data ECMWF initial conditions Grid #X cells # cells Y # cells Z Δ x (km) Δ y (km) Δ z (m) (lowest) Δ t (s)

12 Onda OBS Onda MOD 13-1 Agosto Temperatura (ºC) Onda OBS Onda MOD 13-1 Agosto Velocodad (m/s) ONDA Onda OBS Onda MOD Agosto Dirección (grados) P. Sagunt OBS P. Sagunt MOD 13-1 Agosto 2 Temperatura (ºC) PORT SAGUNT P. Sagunt OBS P. Sagunt MOD 13-1 Agosto 2 Velocodad (m/s) P. Sagunt OBS P. Sagunt MOD Agosto 2 Dirección (grados)

13 Pista OBS Pista MOD Agosto 2 Pista OBS Pista MOD Temperatura (ºC) PISTA RENFE Renfe OBS Renfe MOD Agosto 2 Pista OBS Pista MOD 1 Velocodad (m/s) 13-1 Agosto 2 Dirección (grados) Temperatura (ºC) 13-1 Agosto 2 Renfe OBS Renf e MOD Velocodad (m/s) 13-1 Agosto 2 Renfe OBS Renf e MOD Dirección (grados) 13-1 Agosto 2

14 Emission sources Biogenic Emissions Land use data Biomass factors by land use type Emission factors Meteorological data (T, PAR) Trafic Emissions Geographical distribution and classification of roads VMT (vehicle miles traveled) data Chemical speciation for differnent kinds of vehicles Hourly profiles 3 2 August 13th, OCOVB Monoterpenos Isopreno CO NOX VOC PST SO2 Weekday daily cicle of primary emissions (Kg/h)

15 CMAQ Horizontal: 2 nests - 12 and 4 km Domain 1: Iberian peninsula Domain 2: Valencia Community Vertical: 1 layers - sigma p Chemical mechanism: Carbon Bond IV Meteorology preprocessor: Meteorological Chemistry Interface Processor (MCIP) Advection: pierce-wise parabolic method (PPM) Vertical diffusion: K-theory parameterization Gas-phase reaction solver: quasi-steady state approximation (QSSA)

16 CMAQ results

17 Model performance Grao Zorita O3 mixing ratio [ppm] /13/ 8/14/ 8/14/ 8/1/ 8/1/ Date Puerto Sagunto 8/16/ /16/ O3 concentration [ g/m 3 ] O3 mixing ratio [ppm] /13/ 8/14/ 8/14/ 8/1/ 8/1/ 8/16/ Date Morella /16/ O3 concentration [ g/m 3 ] O3 mixing ratio [ppm] /13/ 8/14/ 8/14/ 8/1/ 8/1/ 8/16/ /16/ O3 concentration [ g/m 3 ] O3 mixing ratio [ppm] /13/ 8/14/ 8/14/ 8/1/ 8/1/ 8/16/ /16/ O3 concentration [ g/m 3 ] Date Renfe Date Paterna O3 mixing ratio [ppm] /13/ 8/14/ 8/14/ 8/1/ 8/1/ 8/16/ Date /16/ O3 concentration [ g/m 3 ] O3 mixing ratio [ppm] /13/ 8/14/ 8/14/ 8/1/ 8/1/ 8/16/ Date /16/ O3 concentration [ g/m 3 ]

18 low VOC low NOx 1 % change in ozone Case % change in ozone [O 3 ]/[NOy] Case 2

19 Indicator distribution VOC sensitive NOx sensitive Percentile th th 9 th th th 9 th O 3 /NOy (case 1) O 3 /NOy (case 2) NE corridor, USA (Sillman and He,22) Lake Michigan, USA (Sillman and He,22) Atlanta, USA (Sillman et al, 1997) San Joaquin, USA (Sillman and He,22) Milan, Italy (Martilli et al., 22)

20 Why the O 3 /NOy transition is different in different environments? O 3 /NOz ~ [S H /L N ] [L N /NOz] [O 3 /S H ] L N /NOz : relates to the removal rate of NOz O 3 /S H : more important S H ~ O 3 and VOC higher VOC ==> lower O 3 /S H ==> lower transition O 3 /S H also varies with photochemical age O3/NOy = [O 3 /NOz] [NOz/NOy]

21 Summary 2 summertime cases analyzed for a Western Mediterranean coastal area. O 3 /NOy threshold values for the transition between VOC- and NOx- O3-sensitivity higher than NE US. Higher threshold values due to: lower ozone levels in Valencian Community (7-1 ppb) uncertainty in regarding O 3 /NOy as a surrogate to the ratio of the source of odd hydrogen to the source of odd nitrogen when calculating the ratios.