1. Dentener JRC Ispra TEMIS 081002007 1 Frank Dentener, Arlene Fiore, Michael Schulz, Martin Schultz, Oliver Wild, HTAP modellers + observations

2. Dentener JRC Ispra TEMIS 081002007 2 Convention of UNECE (United Nations Economic Commission for Europe) The Convention addresses major environmental problems of the UNECE region The Convention has 51 Parties (European countries + USA + Canada) 8 protocols identify specific measures to be taken by Parties to cut their emissions of air pollutants (e.g. EMEP Protocol) Parties develop policies and strategies to combat the discharge of air pollutants through exchanges of information, consultation, research and monitoring.

3. Dentener JRC Ispra TEMIS 081002007 3 The Task Force on Hemispheric Transport of Air Pollution was established in December 2004. The Task Force estimates the hemispheric transport of: ozone and its precursors fine particles acidifying substances mercury persistent organic pollutants Hemispheric transport may be important for understanding air pollution problems in population centers and impacts on remote areas. The Task Force reports its findings to the Convention’s Steering Body of EMEP. HTAP has initiated a comprehensive modeling study to assess the importance of intercontinental transport of air pollution.

4. Dentener JRC Ispra TEMIS 081002007 4 www.htap.org HTAP Interim report: June 2007 (downloadable). Final report: Middle of 2009. TF HTAP jointly chaired by US EPA, EC/DG ENV.

5. Dentener JRC Ispra TEMIS 081002007 5 Source Receptor Relationships F. Dentener, A. Fiore NA EU EA SA First insight about the importance and uncertainties of hemispheric transport processes for ozone and its precursors, particulate matter Using ‘best’ emission inventory and meteorological dataset for 2001. Simulations consist of a reference simulation (2001), and simulations reducing their anthropogenic emissions per region by 20 %. The four regions of interest for Source Receptor Relationships are Europe, North America, East Asia and South Asia. >20 models participated in Experiment 1, 5 more in the SR1 only

6. Dentener JRC Ispra TEMIS 081002007 6 NA EU EA SA 1. SR1 = base case (methane prescribed 1760 ppb) 4. 4x SR4 = regional NMVOC reduction by 20% 2. SR2 = global methane reduction by 20% (1408 ppb) 3. 4x SR3 = regional NO x reduction by 20% 6. 4x SR6 = regional reduction of all anthropogenic emissions by 20% ________________________________________________________ 18 experiments in total (each at least 18 months simulation time) 5. 4x SR5 = regional CO reduction by 20% www.htap.org

7. Dentener JRC Ispra TEMIS 081002007 7 Experiment Set 2: Processes and tracer studies (M. Schultz, O. Wild & D. Shindell) To develop a simple set of diagnostics that can be used to understand the model differences that occurred under Experiment 1. Experiment Set 3: Detailed experiments for Mercury, Ozone, Aerosols, POPs, linkage to campaigns (I. Bey), climate change, regional scale issues. There are a number of issues relevant for HTAP, that can be studied with coordinated experiments. These experiments will asses in more details processes relevant for HTAP. Experiment Set 4: Improved sets of Source Receptor experiments Yet to be defined, further assessment and future scenarios Other experiments

8. Dentener JRC Ispra TEMIS 081002007 8 Which resolution do we choose? 6x4 global 3x2 nhe 1x1 for each region

9. Dentener JRC Ispra TEMIS 081002007 9 Global NOx and VOC emissions

10. Dentener JRC Ispra TEMIS 081002007 10 Seasonal cycles in simulated surface O 3 over the HTAP regions Model range spans ~15-30 ppbv SR1 results from 20 individual models including 5 „twins“

11. Dentener JRC Ispra TEMIS 081002007 11 Seasonality: Monthly mean surface O 3 change in EU from 20% reductions of domestic NO x emissions  Large seasonality masked by annual mean statistic

12. Dentener JRC Ispra TEMIS 081002007 12 Intercontinental Ozone SR relationships Ozone Response [ppbv] in Receptor regions due to 20 % ant. Emission reduction

13. Dentener JRC Ispra TEMIS 081002007 13 20 % perturbation of anthropogenic emissions in specific regions Combined influence of 3 foreign regions emission reductions similar to that in the domestic regions NOx and VOC have the greatest influence- weak non-linearity Ratio Emission NOx/Emission VOC=0.24±0.11 Intercontinental Ozone SR for Europe “foreign”

14. Dentener JRC Ispra TEMIS 081002007 14 NOx the greatest influence Ratio Emission NOx to Emission VOC=0.15±0.06 : half that of Europe Combined influence of 3 foreign regions emission reductions half to that in the domestic regions Intercontinental Ozone SR for North America “foreign ”

15. Dentener JRC Ispra TEMIS 081002007 15 Where do NO emissions from Europe go to? NOy deposition: Source-Receptor analysis

16. Dentener JRC Ispra TEMIS 081002007 16 NOy deposition : Receptor-Source analysis Receptor region Source RegionEUNASAEA EU0.9610.0090.0760.033 NA0.0280.9740.0200.013 SA0.0050.0030.8810.025 EA0.0060.0140.0330.929 If we would change NO emissions in all 4 regions by 20 %; how would it influence a receptor region?

17. Dentener JRC Ispra TEMIS 081002007 17 PM receptor analysis

18. Dentener JRC Ispra TEMIS 081002007 18 Conclusions Perturbation experiments for 4 world regions: NOx, CO, VOC, SO2, EC, POM, CO (Hg Pops). Model spread in perturbation signal typically factor of 2 Ozone sensitivities ca. 1.5-2 ppbv to 20% ant. emission reduction in all 4 regions NA>EU twice as large as all other SR relations Role of methane is an open issue Resolution dependency of seasonal differences Episode analysis Tracer experiments indicate that BL mixing among models varies between 40% and 80% Relatively much attention to interoperability; CF conventions

19. Dentener JRC Ispra TEMIS 081002007 19 The role of observations The first phase of HTAP had very little focus on observations However, most models participated previously in PHOTOCOMP and AEROCOM intercomparisons (2004-2006) Tight timeschedule It was felt that the models in HTAP would not give very different results AEROCOM (http://nansen.ipsl.jussieu.fr/AEROCOM/)http://nansen.ipsl.jussieu.fr/AEROCOM/ Considers surface chemistry observations; satellite AOD/Angstrom, Aeronet, EARLINET. AEROCOM workshop 25/26 October, Lille.

20. Dentener JRC Ispra TEMIS 081002007 20 Ensemble mean model closely resembles ozone-sonde measurements UT: 250 hPa MT: 500 hPa LT: 750 hPa J F M A M J J A S O N D Sonde ± 1SD Model ± 1SD 90-30S 30S-EQ EQ-30N 30-90N ) Sonde data: Logan (1999) + SHADOZ (Thompson et al, 2003 Stevenson et al., JGR, 2005

21. Dentener JRC Ispra TEMIS 081002007 21 Max models + 1 sd -1 sd -Min models Monthly average Surface ozone comparison with measurements Ellingsen et al, ACPD, 2007 S.W. US Brazil N. India; Nepal C. EuropeC. Mediterranean Middle EastS. IndiaS.E. Asia C.E. Africa S. Africa S.E. US Great LakesN. China

22. Dentener JRC Ispra TEMIS 081002007 22 GLOBAL NH TROPICS SH CO comparison with MOPITT Shindell et al, JGR, 2006 “Individual models”

23. Dentener JRC Ispra TEMIS 081002007 23 Van Noije et al, ACP, 2006 NO 2 column: retrievals and models

24. Dentener JRC Ispra TEMIS 081002007 24 HNO 3 wet deposition: models and measurements Dentener et al., GBC, 2006 NADP EMEP IDAF EAnet Kulshrestha Various Galloway

25. Dentener JRC Ispra TEMIS 081002007 25 Next phase of HTAP (2007-2009): Climate, regional, tracer experiments=>2009 report. More linkage to observations; e.g. model experiments are planned focusing on campaigns: TRACE-P; ICARRT-INTEX. The base years for consideration are 2001/2004. Strong need for accepted ‘benchmark’ datasets, to which models and their updates can be routinely compared. QA-QC; fit-for-purpose. What are the quality criteria for these benchmark datasets? Interoperability of model data will help. NILU will select surface observations for establishing benchmark datasets Satellite data?