Application of models of different types to evaluation of POP transport on global scale

Transcription

1 Joint Conference of UNEP and TF HTAP, 7-11 April 2008, Rome, Italy Application of models of different types to evaluation of POP transport on global scale Alexey Gusev Meteorological Synthesizing Centre East of EMEP

2 Outline of presentation Global POP models: multimedia box models and spatially resolved models EMEP intercomparison of POP models: processes, model structure, ranking of selected POPs EMEP TF HTAP intercomparison of POP models: Modeling results on a-hch Updated modeling results on PCBs Comparison of MSCE-POP and GEM/POPs models Concluding remarks

3 Multimedia POP models Spatially resolved Box Global CAN/POPs (Canada) DEHM-POP (Denmark) MEDIA (Canada) MPI-MCTM (Germany) MSCE-POP (EMEP) ClimoChem (Switzerland) ChemRange (Switzerland) Globo-POP (Canada) SimpleBox (Netherlands) Regional ADEPT/LOTOS (Netherlands) ADOM-POP (Germany) HYSPLIT4 (USA) G-CIEMS (Japan) ELPOS (Germany) POPCYCLING-Baltic (Canada) EVN-BETR (UK)

4 Typical multimedia model structure Required input data: Meteorology Sea currents Land cover Leaf area index Soil organic content Seawater organic content Aerosols

5 Pollutant specific input data for modelling Required input data: Physical-chemical properties of POPs Emission data on POPs New EU regulation REACH (Registration, Evaluation, Authorization, and restriction of chemicals) can facilitate the preparation of data on POP properties and emissions for modelling

6 EMEP intercomparison of POP models Period: 2004 up to now Participation: 17 models of different types and resolution including 8 global/hemispheric models (ChemRange, ClimoChem, CAN/POPs, Globo-POP, MEDIA, DEHM-POP, SimpleBox, MSCE-POP) Aim: to improve our understanding of POP long-range transport and behaviour in the environmental compartments. Comparison of parameterizations for selected POPs and POP fate process descriptions used in POP models; Evaluation of mass balance, concentration of POPs in different environmental compartments and intermedia exchange fluxes; Comparison of ranking of selected POPs with regard to P ov and LRTP.

7 EMEP intercomparison of POP models Main results: Most participating POP models provide reasonable agreement in: model parameterisation and description of main processes; simulation of mass distribution and degradation in media; evaluation of concentrations at interfaces of main media; description of spatial distribution of concentrations and depositions; ranking of selected POPs with regard to P ov and LRTP. - EMEP reports on POP model intercomparison study - Scientific paper submitted to the Journal of Environmental Monitoring

8 EMEP intercomparison of POP models: ranking of 14 POPs CCl4 CCl4 HCB HCB HCBD HCBD a-hch a-hch PCB-153 PCB-153 PCB-180 PCB-180 PCB-28 PCB-28 biphenyl biphenyl BDE-99 BDE-99 BDE-47 BDE-47 BaP atrazine p-cresol aldrin Models: Box Spatial BaP atrazine p-cresol aldrin Models: Box Spatial Overall Persistence Long-Range Transport Potential

9 EMEP TF HTAP intercomparison of POP models Source-receptor experiment for selected POPs: a-hch, PCB-153 ( PCB-28 ) Period of the study: 2006 up to now Participated models: MSCE-POP (EMEP) GEM / POPs (Environment Canada) G-CIEMS (Japan)

10 Annual global emission of PCBs North America Europe East Asia South Asia PCB-153 emission for 2001, t/y Global PCB emission inventory for (Breivik et al., 2007)

11 Annual global emission of a-hch a-hch annual emission for 2000, t/y Global inventory of Li et al., 2000

12 Emissions (kt/year) Concentration (pg/m 3 ) Changes in global emission of a-hch and concentrations in the Arctic air Ban of HCH use in China Ban of HCH use in India and USSR Years 0 Global emissions of a-hch and mean concentration in the Arctic air (Li et al., 1998)

13 Contributions of selected regions to annual emission of PCB-153 and a-hch Other 39% NA 0.3% EU 26% EA 4% SA 4% Other 13% NA 14% EA 10% SA 25% EU 65% a-hch PCB-153

14 Levels of pollution by PCB-153 and a-hch for 2001 (MSCE-POP model) Mean annual a-hch concentrations in surface air, pg/m 3 Mean annual PCB-153 concentrations in surface air, pg/m 3

15 a Comparison of MSCE-POP model results with EMEP measurements a-hch PCB-153 Mean annual observed and modelled a-hch and PCB-153 concentrations in surface air

16 Changes (%) in a-hch mean annual concentrations due to 20% decrease of emission Effect of 20% decrease of East Asia emission EA emission 15 t Effect of 20% decrease of European emission EU emission 38 t

17 Sources Sensitivity of a-hch annual depositions to perturbation of emission in selected receptors Receptors EA EU NA SA AR EA EA AR SA EU NA EU NA < 0.01 < < 0.01 < 0.01 SA Receptors Sensitivity: ( D ( E C C D E P P ) ) D E C C (% / %)

18 Changes (%) in PCB mean annual concentrations due to 20% decrease of EU emission Effect of the difference in properties of PCB-28 and PCB-153 PCB-28 More in gaseous phase Higher LRTP Lower persistence PCB-153 More in particulate phase Lower LRTP Higher persistence

19 Changes (%) in PCB mean annual concentrations due to 20% decrease of NA emission Effect of the difference in properties of PCB-28 and PCB-153 PCB-28 More in gaseous phase Higher LRTP Lower persistence PCB-153 More in particulate phase Lower LRTP Higher persistence

20 Comparison of MSCE-POP and GEM/POPs model results on PCBs European region GEM/POPs results (Huang et al., 2007) Annual fluxes across the boundaries of two selected regions

21 Comparison of MSCE-POP and GEM/POPs model results on PCBs North American region GEM/POPs results (Huang et al., 2007) Annual fluxes across the boundaries of two selected regions

22 Concluding remarks Multimedia box models and spatially resolved models are rather close in predictions of general aspects of POP dispersion in the environment Spatially resolved model can provide more detailed description of POP intercontinental transport and source-receptor relationships Physical/chemical properties and properties specific for POPs essentially effect their intercontinental transport Influence of POP emission sources of Europe and East Asia on the pollution levels in the northern hemisphere can be substantial The comparison of MSCE-POP and GEM/POPs model results show good agreement in prediction of PCB-28 fluxes in European and North American regions More active participation of POP modeling experts in the EMEP HTAP POP model intercomparison is required REACH activity can facilitate preparation of data on POP properties and emissions for modeling purposes

23 Concluding remarks (cont.) How do the transport pathways/magnitudes differ by chemical, region, or season? Is there a simple relationship between changes in emissions and changes in pollutant concentrations and deposition levels? How confident are we of our ability to predict the source-receptor relationships? What processes need to be better understood to describe the relative significance of intercontinental transport?