Global and regional multicompartment POP Modelling Co-operation between RECETOX and MSC-E in the field of measurementmodelling approach Victor Shatalov, EMEP/MSC-East Ivan Holoubek, RECETOX
Questions to be addressed Conceptual overview What POPs are transported on intercontinental scales? What are the major processes and sources that determine the intercontinental transport of POPs in the Northern Hemisphere? How does the intercontinental transport differ by chemical, region, or season? What processes need to be better understood to describe the relative significance of intercontinental transport? Modelling What do current models tell us about the magnitudes of intercontinental transport of POPs? How can models with different spatial resolution be nested within one another?
Main peculiarities of POP cycling in the environment Main processes Physical-chemical propertiess Emissions Air Sea Soil Atmospheric transport Partitioning, degradation Wet and dry deposition Transport and sedimentation Convective fluxes and partitioning Gas exchange with soil, sea, vegetation Long-range transport potential Accumulation in soil/seawater/ vegetation with subsequent re-emission Intercontinental transport Multicompartment approach
Ranking substances: long-range transport potential and persistence Chlordecone BDE-28 a-endosulfan Dicofol HxClDd PCP b-endosulfan HpClTd PCN BDE-47 B[a]P PeClD BDE-99 BDE-153 PeCBz HCB HCBD Transport distance (2000 km and more) a-endosulfan b-endosulfan PeClD Dicofol PCP HpClTd HxClDd B[a]P BDE-28 PCN BDE-47 BDE-99 PeCBz BDE-153 HCBD HCB Chlordecone Overall persistence (up to several years) 3280 0 2000 4000 6000 8000 10000 Transport distance, km 0 200 400 600 800 1000 Overall persistence, days
Modelling on different scales regional (e.g. EMEP) Boundary conditions EMEP region global hemispheric EMEP POP global model (under development)
Harmonization of input data for global modelling Land cover Emissions Meteorology Physical-chemical properties
Input data harmonization Land Cover MODIS JRC UMD USGS
Input data harmonization Global emissions: Emissions PCBs [Breivik et al., 2007] HCHs [Li et al., 2000] [Li et al., 2003] ng/m fg T EQ/m 3 2 pg T EQ/m /y PCDD/Fs * EMEP data [UNEP, 1999] PAHs Zhang & Tao (in prep.) HCB compiled by MSC-E using [Bailey, 2001] * For Europe and North America 2 153 g/km emis /y < 0.01 0.01-0.05 0.05-0.1 0.1-0.5 0.5-1 1-3 > 3 Emissions of PCB-153, 2004
Input data harmonization Meteorology Re-analysis data: ECMWF NCEP/DOE (USA) Pre-processing for model use GEM numerical weather prediction model (Meteorological Service of Canada, Côté et al. 1998) - Public available: http://collaboration.cmc.ec.gc.ca/science/rpn.comm/ - CTMs based on GEM: GEM-AQ, GRAHM, CAN-POPs,
Calc, m/s Input data harmonization Comparison of meteodata with measurements for 2001 12 10 8 496 sites <MEAS> = 3.24 <CALC> = 2.38 RMSE = 1.58 Rcorr = 0.64 6 4 2 Annual mean temperature Annual precipitation amount 0 0 2 4 6 8 10 12 Meas, m/s Annual mean surface wind speed
Input data harmonization Pollutant properties for modelling Legacy POPs New substances PAHs (B[a]P, B[b]F, B[k]F, IP) PCDD/Fs (17 toxic congeners) PCBs (8 congeners) -HCH HCB BDE (BDE-28, 47, 99, 153) Endosulfan ( - and -isomers) Dicofol HCBD PCN (PCN-47) PCP Pentachlorobenzene Chlordecone
Pollutant properties: EU Regulation REACH REACH Registration, Evaluation, Authorization and restriction of CHemicals Physical-chemical properties of hazardous substances (POPs) Approaches to environmental risk assessment Software tools and databases ESIS European chemical Substances Information System IUCLID5 Software for managing, storage and exchange of substance-related information
Harmonization Harmonization of input data is important for POP modelling to improve the compatibility of results of different models and to reduce the uncertainties
Monitoring-modelling approach 0.7 0.6 0.5 0.4 Measured Calculated 0.4 0.3 0.2 Measured Calculated 0.5 0.4 0.3 0.2 Measured Calculated 2.5 2.0 1.5 Measured Calculated 0.3 0.2 0.1 0.0 1992 1993 1994 0.1 0.0 2003 2004 2005 0.1 0.0 2003 2004 2005 1.0 0.5 0.0 2003 2004 0.6 Measured Calculated 3.0 Measured Calculated 0.5 2.5 0.4 2.0 0.3 1.5 0.2 1.0 0.1 0.5 0.0 1993 1994 1995 0.0 2003 2004 2005 0.6 Measured Calculated 1.5 Measured Calculated 0.5 1.2 0.4 0.3 0.2 0.9 0.6 0.1 0.3 0.0 2003 2004 2005 0.0 2004 2005 Measured and calculated PCB-153 air concentrations in 2005, pg/m 3 (calculated from 1970 to 2005)
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Monitoring-modelling approach The analysis of disagreements 0.30 0.25 0.20 0.15 0.10 0.05 0.00 SE14 B[a]P emissions for 2005 Measured Calculated Density of backward trajectories arriving at SE14 SE14_Jan_2005_NoDegr 0-20 20-100 100-400 400-1000 1000-2000 2000-5000 5000-12000 SE14_Feb_NoDegr 0-20 20-100 100-400 400-1000 1000-2000 2000-5000 5000-12000 SE14_Mar_2005_NoDegr 0-20 20-100 100-400 400-1000 1000-2000 2000-5000 5000-13000 January February March
Monitoring-modelling approach Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Refinement of seasonal variations of pollution 0.6 CZ3 Without photodegradation 0.5 0.4 0.3 0.2 0.1 0.0 Measured Calculated Improvement modelling results for B[a]P by inclusion of photodegradation process to the model
Monitoring-modelling approach: conclusions The approach allows: Validating model calculations against measurements. Evaluation of the input data. Improvement of model parameterizations and descriptions of environmental processes. Filling gaps in the information given by measurements. Calculating source-receptor relationships, evaluating new substances,.
EMEP TF HTAP questions What do current models tell us about the magnitudes of intercontinental transport of POPs?
Modelling results: spatial distribution of contamination Difference: intercontinental transport re-emission (long-term accumulation) Boundary and initial conditions Hemispheric calculations (long period 30 years) Current year With intercontinental EMEP sources only transport Contamination levels for 2,3,4,7,8-PeCDF from sources of Europe and North America
Source-receptor relationships Contribution of intercontinental transport Contribution of intercontinental transport to depositions of PCDD/Fs to Europe (from North American sources) Up to 20% 50% at particular locations
EMEP TF HTAP questions How does the intercontinental transport differ by chemical, region, or season?
Source-receptor relationships Dependence of intercontinental transport on source location Air concentrations caused by a conventional point source of pentachlorobenzene (PeCBz), annual means, relative units from North America from Europe
Source-receptor relationships Dependence of intercontinental transport on pollutant properties Air concentrations caused by a conventional point source in Europe, annual means, relative units B[a]P PeCBz
Source-receptor relationships Dependence of intercontinental transport on season PCB-28 transport from North American emission sources Selected regions PCB-28 transport from European emission sources
EMEP TF HTAP questions Using predictive transport models, what are possible methods for calculating sourcereceptor relationships?
Source-receptor relationships Source-receptor calculation scheme Continental sources Anthropogenic sources Europe of continents North America European American sources Particular country Re-emission from underlying surface Air transport Re-volatilization Re-suspension Receptors (continents, regions, ) Environmental compartments
Source-receptor relationships 1990 1992 1994 1996 1998 2000 2002 2004 1990 1992 1994 1996 1998 2000 2002 2004 Re-emission contribution PCDD/F emission trend in the UK and the concentrations in soil Re-emission/emission ratio in the United Kingdom 16 100 12% 12 Soil conc., fg TEQ/g 75 10% 8% 8 4 0 Emissions, pg TEQ/m 2 /day 50 25 0 6% 4% 2% 0% Re-emis/Emis ratio, %
Source-receptor relationships Iceland Norway Finland Sweden Ireland Contributions of various source categories to contamination of European countries 100% 80% 60% Intercontinental transport: 40% up to 35% 20% 0% Re-emission : 30% 60% Intercontinental Internal contribution EMEP transboundary Re-emission Total annual depositions of PCDD/Fs
Conclusions A lot of POPs, (e.g. PCBs, HCB, pentachlorobenzene, hexachlorobutadiene, ) are transported on intercontinental scale. Main processes affecting POP intercontinental transport are partitioning and degradation in the atmosphere, deposition and gaseous exchange with underlying surface. Harmonization of input data (land cover, emissions, meteorology, physical-chemical properties, ) is important for POP modelling to improve the compatibility of results of different models and to reduce the uncertainties. European Regulation REACH can be a source of the information on POP properties and emissions. Models of different resolution (regional, hemispheric and global) should be nested to one another to provide realistic pattern of contamination.
Conclusions Monitoring-modelling approach should be used to improve model predictions and to reduce the uncertainties. Magnitudes of intercontinental transport are essential for particular POP. Even for PCDD/Fs it can reach 20% 50% for some regions in Europe. POP intercontinental transport strongly depend on chemical, region, or season. In evaluation of source-receptor relationships, contributions of intercontinental transport and re-emissions due to long-term accumulation should be taken into account. Re-emission processes require further investigation. For improvement of model parameterizations of these processes and model validation more measurements in the environmental compartments other than the atmosphere is needed.
Thank you for your attention!
Source-receptor relationships Contribution of intercontinental transport Contribution of intercontinental transport to depositions of PCDD/Fs to Europe (from North American sources) g/km2/y In te rcon tine ntal tran spo rt < 0.0 1 0.01-0.0 2 0.02-0.0 4 0.04-0.1 0.1-0.5 0.5-1 > 1 Up to 20% 50% at particular locations