8 Trend Analysis of Air Pollution and Nitrogen Deposition Over …
49
A comparison of the EMEP4NL model output is made with results from the
OPS-model over the same period, for which the same emissions are used. The OPS
model is driven with yearly specific meteorological fields provided by the Royal
Netherlands Meteorological Institute (KNMI).
8.3 Some First Preliminary Results of Trend Run
with EMEP4NL and OPS
The calculations as performed with the EMEP4NL and OPS model over 2006–2015
give a plethora of output data like concentrations of ammonia and other precursors;
secondary inorganic aerosols; particulate matter; wet and dry deposition of sulphur
and nitrogen. The focus of this trend analysis will initially be on the different nitrogen
components like ammonia, ammonium, nitrate, and dry and wet nitrogen deposition
and, in particular, the relation of these components to the decrease in ammonia
emissions in the Netherlands over the period 2006–2015. An extensive discussion
of this whole topic is beyond the scope of this abstract, so we only show some
preliminary results here.
Figure 8.1 (top panel) shows the wet deposition of NH 4 over the whole period
as measured (LML/MAN) and calculated (EMEP4NL). Measurements over this
period have been taken at 8–11 monitoring stations distributed more or less homogeneously over the Netherland. One can see there is an underestimation of 1.35 with the
EMEP4NL model, which is partly due to the fact that precipitation is underestimated
by the WRF model. The spatial representation however is quite good. Figure 8.1 (bottom panel) shows the trend of (normalized) ammonia concentrations over the period
2006–2015 for respectively measurements (LML/MAN), the EMEP4NL model and
the OPS model.
8.4 Conclusion
The comparison between measurements and calculations of ammonia concentrations
shows good agreement for both models, EMEP4NL and OPS. Also, the models agree
well in this respect. The spatial distribution of the wet deposition of ammonia is well
represented by EMEP4NL, but the deposition is underestimated by the model. A
detailed analysis of the trends of all the different nitrogen components and their
relation to the decreasing ammonia emissions in the Netherlands, is currently being
performed. A presentation of more detailed results of this analysis is beyond the
scope of this short paper, and will hence be presented elsewhere.
Acknowledgements This research was financed by the Dutch Ministry of Agriculture, Nature and
Food Quality.
49
A comparison of the EMEP4NL model output is made with results from the
OPS-model over the same period, for which the same emissions are used. The OPS
model is driven with yearly specific meteorological fields provided by the Royal
Netherlands Meteorological Institute (KNMI).
8.3 Some First Preliminary Results of Trend Run
with EMEP4NL and OPS
The calculations as performed with the EMEP4NL and OPS model over 2006–2015
give a plethora of output data like concentrations of ammonia and other precursors;
secondary inorganic aerosols; particulate matter; wet and dry deposition of sulphur
and nitrogen. The focus of this trend analysis will initially be on the different nitrogen
components like ammonia, ammonium, nitrate, and dry and wet nitrogen deposition
and, in particular, the relation of these components to the decrease in ammonia
emissions in the Netherlands over the period 2006–2015. An extensive discussion
of this whole topic is beyond the scope of this abstract, so we only show some
preliminary results here.
Figure 8.1 (top panel) shows the wet deposition of NH 4 over the whole period
as measured (LML/MAN) and calculated (EMEP4NL). Measurements over this
period have been taken at 8–11 monitoring stations distributed more or less homogeneously over the Netherland. One can see there is an underestimation of 1.35 with the
EMEP4NL model, which is partly due to the fact that precipitation is underestimated
by the WRF model. The spatial representation however is quite good. Figure 8.1 (bottom panel) shows the trend of (normalized) ammonia concentrations over the period
2006–2015 for respectively measurements (LML/MAN), the EMEP4NL model and
the OPS model.
8.4 Conclusion
The comparison between measurements and calculations of ammonia concentrations
shows good agreement for both models, EMEP4NL and OPS. Also, the models agree
well in this respect. The spatial distribution of the wet deposition of ammonia is well
represented by EMEP4NL, but the deposition is underestimated by the model. A
detailed analysis of the trends of all the different nitrogen components and their
relation to the decreasing ammonia emissions in the Netherlands, is currently being
performed. A presentation of more detailed results of this analysis is beyond the
scope of this short paper, and will hence be presented elsewhere.
Acknowledgements This research was financed by the Dutch Ministry of Agriculture, Nature and
Food Quality.