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

The motivation and background

The model set up Comparison :

Meteorological variables Air quality variables

Conclusions

Outline of our talk

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

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

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

Time ： June to August ， 2012 LOTOS-EUROS was run for the target domain

(00E- 110E, 490N- 550N) 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

Meteo （ KNMI ） : 10 stations Air quality （ LML of RIVM ） : 8 regional background

stations

Observation data

Surface temperature

Comparison: Meteorological variables

Relative humidity

Wind speed

Boundary layer height

O3

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

Any questions?