1. A comparison of air quality simulated by LOTO-EUROS driven by Harmonie and ECMWF using observations from Cabauw Jieying Ding, Ujjwal Kumar, Henk Eskes, Henk Klein- Baltink

2.  The motivation and background  The model set up  Comparison :  Meteorological variables  Air quality variables  Conclusions Outline of our talk

3.  Current air quality forecasts by LOTOS-EUROS is driven by ECMWF meteorology which is available at coarse resolution (~15 km)  HARMONIE meteorology is available at a very high resolution at ~2.5 km. HARMONIE is the new high resolution numerical weather model operational at KNMI since 7 Dec 2011.  The purpose of this study is to evaluate LOTOS- EUROS driven by HARMONIE and ECMWF meteorology using (Cabauw) observations Motivation and Background

4.  What are the differences of meteorological variables between ECMWF and Harmonie?  What are the differences of air quality simulations using two meteorological drivers?  How do the differences of meteorological conditions affect the air quality in LOTOS-EUROS? Research questions

5. The main meteorological variables affect air quality processes in LOTOS-EUROS

6.  Time ： June to August ， 2012  LOTOS-EUROS was run for the target domain (0 0 E- 11 0 E, 49 0 N- 55 0 N) at the high resolution (~3.5 km) using HARMONIE meteorology (available at 2.5 km resolution)  LOTOS-EUROS was also run for the target domain at ~3.5 km resolution using ECMWF meteorology (available at ~15 km resolution).  Chemical boundary conditions are from MACC: Model set up

7.  Meteo （ KNMI ） : 10 stations  Air quality （ LML of RIVM ） : 8 regional background stations Observation data

8.  Surface temperature Comparison: Meteorological variables

9. Relative humidity

10. Wind speed

11. Boundary layer height

12. O3

13.  The surface temperature difference between two meteorological models is around 1.5 to 2 K.  The differences of surface relative humidity, wind speed between two models are large, at least above 10%.  The boundary layer height simulated by Harmonie is low compared to observations.  Apart from the boundary layer height, it is hard to show which meteo model is better.  The difference in air quality results between the two simulations is large. The RMS difference for ozone is 20ug/m3. Conclusions

14. Any questions?