Air quality expert group - Fine particulate matter (PM2.5) in ... - Defra

NO3 – concentration µgm -3
12
10
8
6
4
2
0
Bush 1 (LHS)
2002 2003 2004 2005 2006 2007 2008
time / month
Annex 2: PM modelling in the UK
Figure A2.5.1: Monthly-averaged EMEP4UK-simulated fine nitrate (< 2.5
AGANET EMEP4UK rv3.7
µm) (bottom of the blue shading) and coarse nitrate (2.5-10 µm) (width of
the blue shading) for the model grid square containing the Bush site (µg m-3 NO3 - ). The top of the blue shading corresponds to total nitrate. The red line
shows the monthly observations from AGANet (which has a sampling cut-off of
approximately PM4).
42. Figure A2.5.2 shows the EMEP4UK annual average total surface nitrate over the UK
for the year 2003. A strong south-east to north-west gradient is visible, reflecting
the co-location of pollutants such as ammonia and oxidised nitrogen in the southeast
of the UK and the vicinity of countries such as Germany, the Netherlands and
France which have high emissions of ammonia and nitrogen oxides and contribute
to export of nitrate to the UK domain. Further examples of EMEP4UK applications
can be found in Doherty et al. (2009) and Vieno et al. (2010).
Figure A2.5.2: EMEP4UK calculated annual average surface nitrate for the year
2003 (µg m -3 ).
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