Title Atmospheric Modelling at MSC-W David Simpson and Leonor Tarrason TFIAM - Haarlem, 7-9 May 2003

EMEP Unified Model I Meteorologisk Institutt met.no Horizontal resolution: Regional 50 x 50 km 2 (170 x 133 cells, centered over Europe) Vertical resolution: 20 σ-layers (up to 100 hPa), 10 in PBL Off-line meteorology: 3-h meteorological input from HIRLAM Boundary conditions: Flexible choice (modelled from Oslo CTM2, TM3 or climatological Logan data for O3). Currently climatological BCs are used. Emissions: EMEP emissions estimates for SO x, NO x,NH 3, VOC,CO PM 2.5 and PM 10 from TNO-CEPMEIP project

Schematic structure of EMEP UNIFIED Boundary, lateral and initial conditions Advection (Bott scheme) Dry and Wet Deposition Emissions UNI - ACID EMEP acidification 10 species + PPM UNI - AERO EMEP acidification 14 species, 4 size modes UNI - OZONE EMEP photochemistry 69 species, 170 reactions Aerosol dynamics Multimono Meteorological conditions PPM mass: 2 species SOA module

Main developments in UNI- OZONE since July 2002 Meteorologisk Institutt met.no Dry deposition routines 1) Ecosystem-dependant outputs. 2) Introduction of the effect of NH3 in SO2 surface resistance Emission routines 1) New description of height of emission by sector (specially for power combustion and industrial sources). 2) New gridded data for PM 10 and PM 2.5 from TNO/CEPMEIP Wet deposition routines 1) Heterogeneous sulphur chemistry explicitly introduced Chemistry 1) Introduction of oxidant limitation in sulphur chemistry 2) Introduction of coarse nitrate

UNI-OZONE – the basic conflict: Meteorologisk Institutt met.no ― Model should be Operational as Soon as Possible e.g. For IAM tests ― Model should perform as perfectly as possible For S & N compounds, O3, AOTs, exceedances From 1980s to year 2010

O 3 daily max Timeseries Meteorologisk Institutt met.no

O 3 daily max Selection of stations active since 1990 (18) Meteorologisk Institutt met.no

1990 Bias=-30%, r= Bias=-18%, r=0.50 Meteorologisk Institutt met.no NO 2 – All EMEP stations

NO 2 correlation coefficient in city areas CITY DELTA model intercomparison1999 Meteorologisk Institutt met.no Paris, day Paris, nigth Milan, night Milan,day (EMEP Unified in orange)

Conclusions on EMEP model O 3 performance Meteorologisk Institutt met.no The UNIFIED EMEP model performance has studied in comparison with EMEP stations for 1990,1995 and 2000 and in CITY DELTA stations for  Correlation coefficients in regional scale are high, between 0.6 and 0.8 for daily mean ozone and daily max values. The summer mean ozone bias is below 10%.  For NO2, correlation coefficients at regional scale vary between 0.5 and 0.7 but the model has difficulties to reproduce at night time NO 2.  At Mediterranean stations, model performance is poorer than in average for the rest of Europe, as expected given uncertainties in transport, emissions, and boundary conditions for Mediterranean regions.  Frequency distributions show that the model tends to underestimate high ozone values: the model tends to underestimate exceedance days.  Some changes likely when deposition routines “settle down” - likely more O3 in model. Note that the underestimation of high ozone values is more pronounced at the end of the 1990s  consistent with the general trend of increase of ozone mean values

New Targets? Recent Developments in Crtitical Levels/Loads Discussions Meteorologisk Institutt met.no AOTx or Fluxes? 1) AOTx still recommended for crops, forests and seminatural vegetation 2) Flux approach for wheat and potato possible. AOTx? 1) AOT40 maintained for crops and seminatural 2) AOT40 and AOT30 perform similarly for forests- AOT40 kept 3) modified AOT30 – mAOT30 for short-term CL 4) CLs: 3 ppm.h for crops/seminatural 5 ppm.h for forests Flux CLs, thresholds? 1) CL suggested for wheat and potato. 2) Threshold of 6 nmole/m2/s for wheat ( – about 20 ppb at full conductance).... over 4 week period 3) Suggestion for alternative flux approach for deciduous forest - based upon beech. Threshold of 1.6 nmole/m2/s... over growing season.

New Targets? Recent Developments in Crtitical Levels/Loads Discussions Meteorologisk Institutt met.no Change: height of AOT40 AOTx and fluxes should both be estimated at the top of the canopy. Measurements are usually made at 3—5 m above ground level. Methods are suggested for converting measured data to the appropriate height. For crops, this will give lower levels of AOT40 – less exceedance For forests, this will give higher levels – more exceedance.

Forests: new CL = 5000 ppb.h Meteorologisk Institutt met.no

Landuse Issues Meteorologisk Institutt met.no If EMEP delivers ecosystem-specific deposition estimates, should landuse maps be harmonised? Current maps: 1) SEIY map: 200 categories – explicit wheat, barley, etc. Basis for current deposition module Covers full EMEP model area 2) CCE map 16 categories – based upon CORINE/PELCOM link to ecosystems? 3) CCE- maps for eutrophication/acidification?? 4) Other – national maps, 'new' maps (satellite, JRC, etc.) 1

EMEP Model Evaluation Decided at TFMM, Valencia, 2003 Thorough Review of EMEP model For presentation at November, 2003 workshop, Oslo, and TFMM, April 2004 Compare with measuments, models Process investigations Identified projects: –Sweden (IVL): ecosystem deposition –Netherlands (TNO): model intercomparison –Others... during May 2003

Contributions Consider choice of parameterisations, chemistry, inputs, etc. Quantify “state-of-the-art” Identify key field measurements Examine source-receptor relationships compared to national studies. EMEP MSC-W to prepare full documentation See

Immediate future: Deliver! –Model is “ready to run” –Test runs to IIASA / IER (MERLIN) –4-6 countries –Different emission levels –Investigate linearity