Model calculation of tropspheric ozone distibution Masayuki TAKIGAWA, Masanori NIWANO, Hajime AKIMOTO (Frontier Research Center for Global Change, Kanagawa, Japan) Masaaki TAKAHASHI (Center for Climate System Research, Univ. of Tokyo, Chiba, Japan) Acknowledge: APN 21 July 2007, CITES-2007
Contents 1. Introduction 2. Chemical weather forecasting system with global chemical transport model CHASER 3. Global/regional nested model using WRF/Chem and CHASER 4. Summary
1. Introduction Our institute (Frontier Research Center for Global Change) mainly focused on global change issues, and the result of two models (CHASER and FRCGC/UCI) are contributed to IPCC AR4. Short-time forecast is also an important topic, and we developed global version in 2002, and are developing regional version since 2006. Earth Simulator FRCGC
2. Global Chemical Weather Forecast System • 7-day forecast was offered everyday at PEACE-A and PEACE-B campaign period (6 Jan. to 23 Jan., 2002 and 21 Apr. to 17 May, 2002, respectively) for the decision of flight course. • To compare the model results with aircraft and/or ground-based observations. • To evaluate the inter-continental transport of chemical species (e.g., Europe → Asia, Asia → North America, North America → Europe). • To offer air-quality information to the public via WWW and so on.
Outline of CHASER • Global model (based on CCSR/FRCGC/NIES AGCM 5.7) • It treats 54 chemical species, 94 gas-phase reactions, 25 photodissotiations, 4 liquid-phase reactions, and 1 heterogeneous reaction on the surface of sulfate aerosols • Online coupling of the meteorological field and the transport of chemical species • Online coupling of radiation and the distribution of chemical species • Horizontal resolution : T42 (about 300km x 300km) • Vertical resolution: 32 layers (up to 45 km, and 1 km interval in the free troposphere) • Emission: mainly based on EDGAR and GEIA • Biomass burning: parameterized by the hot spot data from AVHRR and ATSR • Aircraft NOx: EDGAR • Lightning NOx: Price and Rind (1992)
Flight course during PEACE-A/B campaign obs.&model CO tagged CO obs.&model CO tagged CO Takigawa et al., 2005
Horizontal transport following to the passing of low pressure system （PEACE-A flight 2, 7 January, 2002） Observed CO mixing ratio at 2km height Calculated CO mixing ratio at 900hPa or lower Takigawa et al., 2005
vertical transport by convection （PEACE-B flight10, 14 May, 2002） upper right：Sea level pressure (contour) and CO increase rate at 300hPa by convection (pixel) lower right：CO mixing ratio at 300hPa lower left：Satellite image on 14 May, 2002 red line：flight course Takigawa et al., 2005
vertical transport by convection （PEACE-B flight10, 14 May, 2002） a) b) CO (PEACE-B Flight#10 14/May/2002) Tagged CO for PEACE-B Flight#10 100 Obs. Model (N.China) Model Model (S.China) Model (Europe) Model (N.America) Model (Japan) 200 Pressure [hPa] 300 400 500 600 700 800 900 1000 0 50 100 150 200 250 300 350 0 20 40 60 80 100 Mixing ratio of CO [ppbv] Mixing ratio of Tagged CO [ppbv] Figure 17. As in Figure 10, but from flight 10 of the PEACE–B campaign on 14 May 2002. The bold line indicates CO values from 6:48 UTC to 7:22 UTC, respectively. Takigawa et al., 2005 Observed (red solid line) and calculated (green solid line) CO mixing ratio on the flight course of flight 10 in PEACE-B.
Budget analysis of CO over Japan In winter, long-range transport plays an important role for the budget of CO over Japan. The fraction of China CO is also quite large. b) CO budget over Japan (120-145E,30-45N) in LT(<2km) 0.5 N.China+Korea Asian LRT Chemical S.China S.Asia Japan B.B.(Asia) 0.4 Europe N.America other region B.B.(Siberia) B.B.(other) 0.3 Produded from VOC oxidation [Tg] 0.2 0.1 0 D J F M A M D J F M A M D J F M A M a a a e e e e p e p e p n n n a a a a a a b b b c c c r r r / r y / r y / r y / / / / / / / 2 / / 2 / / 2 / 2 2 / 2 2 / 2 2 / 2 2 2 2 2 2 0 2 0 2 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 2 0 2 0 2 2 2 1 2 1 2 1 2 2 2 2 2 2 2 takigawa et al. (2005)
Example of long-range transport of ozone precursors Colored plumes denote the isosurface of pollutants (yellow: CO, green: NOx, and blue: SO2). The color of sea level is also denotes the surface ozone level. The transport of plumes from Europe to Asia can be seen. The transport of surface ozone from Asia to North America can be seen.
3. Regional-scale chemical weather forecasting 1. The main objective of “urban-scale chemical weather forecast” project is: • Offering daily forecast of ozone and other chemical species over Kanto region by using high-resolution(3km?) CTM. 2. For this purpose, we are now developing a nested global/ regional chemical transport model based on CHASER and WRF/Chem.
outline of “1-way nested global/regional chemical transport model system” CHASER (global model part) Model domains for WRF/Chem 45 1. Horizontal resolution: about 2.8 degree x 2.8 degree 40 2. Vertical resolution: 32 layers up to 45km Latitude [deg] 35 3. Meteorological field: driven by NCEP ds083.2 30 WRF/Chem (regional model part) 25 120 125 130 135 140 145 150 Longitude [deg] 1. Based on WRF-ARW version 2.1.2 2. 2-domain nesting (15-km resolution for Japan and 5-km resolution for Kanto) 3. RADM2 chemistry with aerosols 4. initial and lateral boundary for chemical species from CHASER (every 3 hour) 5. initial and lateral boundary for meteorology from JMA/MSM (every 3 hour) 6. Emission: EAGrid 2000 with 1km resolution over Japan. Hourly, weekly (automobile only), an monthly variation are taken into account. 7. Emissions of other species in Asia is taken from REAS, and emissions in other regions taken from EDGAR20000.
CO Emission for Domain 1 (upper left), Domain 2 (upper right), and monthly and daily variation at Shinjuku (lower right).
Time Schedule of forecast calculations 18Z Time in the real world 6hr spin-up 15hr forecast 00Z 6hr spin-up 15hr forecast 06Z 6hr spin-up 15hr forecast 12Z 6hr spin-up 15hr forecast 18Z 6hr spin-up 15hr forecast 18Z 00Z 06Z 12Z 18Z 00Z 06Z Time in the model calculation Calculation is done three times (1: initial/boundary cnd. for meteorology are forecast, 2: initial is analysis and boundary is forecast, and 3: initial/boundary are analysis). 15-hours forecasts are offered four times in a day, with a lead time of 9-10 hours.
羽生(Saitama) 熊谷(Saitama) 千代田区神田司町(Tokyo) 南区横浜商業高校(Kanagawa) Observed and calculated ozone in Aug.2006
Isosurface of Ozone(80ppbv) colored by the height during 05-08 August Eastward movement of Typhoon 200607(MARIA) was quite slow in the model. There were three typhoons on 8 August, and the movement of Typhoon MARIA seems to be affected by other tyophoons.
of initial condition for the short-range forecast. field is same. It seems the impact of lateral boundary is not so large compared to that In 00-05hr forecast and analysis meteorology, the initial condition of meteorological even if the 06-11hr forecasted meteorology field was applied. The correlation coefficient is 0.7 or higher at about 70% of all stations, Change of the distribution of correlation coefficient caused by the difference of met. field (251 stations in Domain 2) 06-11hr fcst met. 0.6 00-05hr fcst met. analysis met. 0.5 0.4 0.3 0.2 0.1 0 0.5 0.15 0.25 0.35 0.45 0.55 0.65 0.75 0.85 0.95
Summary • The global model CHASER well captured the transport of ozone precursors corresponding with synoptic scale weather. • Convective transport seems to be important over Southern China in spring. • Long-range transport should be taken into account to reproduce CO distribution, especially in winter. • The global-regional nested model well captured ozone increase events, and the correlation coefficient between forecasted and observed ozone showed 0.7 or higher at 70% of air-quality monitoring stations over Kanto region. • Intra-continental transport of pollutants from China plays an important role for the air quality over Japan, even in summer.
Example of applications for a public information Science Museum in Tokyo http://www.jamstec.go.jp/frcgc/gcwm/index.html Aichi EXPO in 2005
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