1. Jan Eiof Jonson, Peter Wind EMEP/MSC-W
EMEP Hemispheric and Global models: Model validation and the HTAP model intercomparison
Jan Eiof Jonson, Peter Wind
EMEP/MSC-W
TFMM 27th April 2007

2. EMEP Hemispheric/Global model versions
Hemispheric model
ERA 40 meteorological data. Validated in EMEP Technical Rep. 2/2006
To be replaced by
Global model
First running version ready
ECMWF ERA 40/IFS meteorological data

3. Evaluation of Hemispheric EMEP model: Polar stereographic, 100x100 km2 resolution true at 60 deg. N
Similar performance to the regional scale EMEP model
Slightly worse correlation with primary species and ozone due to coarser resolution (100x100 km)
Improved performance for Ozone in Mediterranean areas and for SIA and wet deposition – due to use ECMWF met fields
General underestimation of ozone free tropospheric levels estimates, need for introduction of convective exchange

4. Background:
In particular tropospheric ozone is increasing on a
hemispheric scale. Environmental targets may not be reached
with control measures on a regional/continental scale alone.
Order of 20 participating (mainly global) models

5. The 4 HTAP regions

6. HTAP
comparison
EMEP

7. Minamitorishima
Yonagunijima
Tsukuba
Ryori

9. Polar sites
The cause of this
Underestimation
Is unclear
Barrow

10. HTAP CO comparison
EMEP

11. TF HTAP PM2.5 comparison
EMEP

12. PM10 and PM2.5, European EMEP sites

13. HTAP: wet deposition of ox. nitrogen
EMEP

14. North American: Ozone sonde stations
Spring and summer underestimation of free tropospheric ozone
by EMEP hemis – related to performance in high latitudes and mountain areas

15. Asian Sonde Stations

16. European Stations: Ozone sonde data

17. O3 vertical profiles Uccle
Late Autumn (day nr. 300)
Summer day (day nr. 171)
EMEP

18. Satellite comparison: NO2 from GOME

19. HTAP scenarios: reducing emissions by 20% in 4 regions (Europe, North America, East Asia and South Asia)
SR1: Reference model run
SR2: Reduced methane
SR3: Reduced NOx emissions in 4 regions
SR4: Reduced CO emissions in 4 regions
SR5: Reduced VOC emissions in 4 regions
SR6: All emissions reduced in 4 regions

20. SR3EU: Effect on O3 (somo35) of reducing European NOx emissions
EMEP

21. SR4EU: Effect on O3 (somo35) of reducing European VOC emissions
EMEP

22. SR3EA: Effect on O3 (somo35) of reducing East Asian NOx emissions
EMEP

23. SR3EU: Effect on wet depositin of ox
SR3EU: Effect on wet depositin of ox. N of reducing European NOx emissions
EMEP

24. SR6NA: Effect on all N. American emissions on PM2.5
EMEP

25. First global model version
Meteorological data: ECMWF ERA40 or IFS data.
Landuse: From MM5 (23 classes condensed to 17). For original EMEP domain landuse as in EMEP regional model.
Problems with lat long grid at the poles. Advection solved for latitude rows. If the Courant number is exceeded the timestep is reduced. If the timestep is less than 1/10 of general timestep (1800s) then all cells in row are mixed (in practice north/south of 85N/S).

26. Minamitorishima
Yonagunijima
Tsukuba
Ryori

27. Polar sites: Underestimation turned to overestimation
Polar sites: Underestimation turned to overestimation. May be related to filtering of met. data
Barrow, Alaska

28. Summing up
EMEP Hemispheric model is working, and model performance is similar to the regional EMEP model.
The model has contributed in the TF HTAP model inter-comparison.
The first version(s) of a global EMEP model version is working. Unresolved issues in particular related to advection needs to be resolved.

29. Future needs and activities:
There is a need for more validation
Preferably vertically resolved - ozone sondes, aircraft data, lidar measurements etc.
Satellite measurements
Ground measurements (from national and international networks)
Practical obstacles with regards to data formats availability etc.
Require indebt knowledge of data quality.
What steps should TFMM/CCC take contributing to this process?

30. Asian Sonde Stations

31. European EMEP sites annual NO2 and nitrate particles

32. Annual SO2 and sulphate, European EMEP sites

33. Work plan
Further evaluate the performance of the hemispheric model
Evaluation of the effect of convection in free tropospheric ozone
Further investigate vertical profiles of pollutants over Europe (in cooperation with France)
Contribute to TFHTAP model intercomparison
Explore possibilities of enhanced collaboration with the satellite, LIDAR and remote sense communities
Further evaluate the refinement of horizontal and vertical scales to allow studies of impact in ecosystems and health (in cooperation with Parties)

34. Comparison with surface data and CTM2
Mountain stations
Black: Daily Max Ozone Measurements
Red: EMEP hemispheric
Green: CTM2 model
Over Europe, better performance than elsewhere, specially than in East Asia (effect of emissions?)

35. NO2 in different regions