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

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

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

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

The 4 HTAP regions

HTAP comparison EMEP

Minamitorishima Yonagunijima Tsukuba Ryori

Polar sites The cause of this Underestimation Is unclear Barrow

HTAP CO comparison EMEP

TF HTAP PM2.5 comparison EMEP

PM10 and PM2.5, European EMEP sites

HTAP: wet deposition of ox. nitrogen EMEP

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

Asian Sonde Stations

European Stations: Ozone sonde data

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

Satellite comparison: NO2 from GOME

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

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

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

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

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

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

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).

Minamitorishima Yonagunijima Tsukuba Ryori

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

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.

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?

Asian Sonde Stations

European EMEP sites annual NO2 and nitrate particles

Annual SO2 and sulphate, European EMEP sites

Work plan 2007 - 2008 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)

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?)

NO2 in different regions