1. PM Trends PM10, PM2.5, PM10-PM2.5 (not possible in 90s)
Sulfate, Nitrate, Ammonium
NO3+HNO3; NH3+NH4
Precursors (SO2, NOx, VOC, NH3)
Precipitation (sulfate, nitrate, ammonium, pH?)
BC/EC, TC, OC
Elemental composition, Sources (very few stations)

2. Time
/ /
Percent change : 100%: median, beginning
An option would be to set the trend line to 100% at 2001/1996/2007
Advantage: if e.g is missing .. The reference year would be the same as for a complete dataset

3. PM2.5/PM10 Hardly complete data in 90s, only data between 2002-2012
Significant downward PM10 trends throughout Europe (typically 40-60%). Decreases more pronounced in Summer, in Winter some increases in Urban areas.
Decreases in PM10 more pronounced for traffic/industrial sites
PM2.5: Lower amount of stations than PM10. Rather decreasing trend but also some increasing ones.
Ox. N conc in precip: tendency for larger trend in model
NO3+HNO3 in air: few sites have trends (more in model)
Difficult to see any trends for 10 years period

4. 2. Trend analysis: PM10 (bkgd)
Key results :
Decrease throughout Europe
Downward trend more pronounced in summer. 4

5. 2. Trend analysis: PM10 (whole set)
Key results :
Decrease throughout Europe
Downward trend more pronounced in summer 5

6. SO2, sulfate, precipitation sulfate
Consistent picture : strong decrease basically everywhere typically 60% in 20 years.

7. SO4 SO4 (Sen slope: ugS/m3 per year), 1990-2012 OBS MOD -2.6 -3.2 -4.4
(%yr-1)
-2.6
-3.2
(%yr-1)
-4.4
-4.8
(%yr-1)
-4.3
Model slightly larger trend

8. SO4 (Sen slope: % per year), 1990-2012
Not significant

9. S in precip (Sen slope: mgS/l per year), 1990-2012
OBS
MOD
90-12(%yr-1)
-3.1
-3.8
90-01(%yr-1)
-5.5
02-12(%yr-1)
-4.4
-5.1

10. NH3, NH4, NH4 precipitation, NH3+NH4
NH3: little data. Trends are influenced by changing partitioning (less sulfate leading to more gaseous NH3)
NH3+NH4, NH4 precipitation typically up to 25% decrease in 20 years. Trends for 10 years are not significant

11. Red. N in precip (Sen slope: mgN/l per year), 1990-2012
Field: model
Circle: obs
Black circle: not significant
trend
OBS:-1.1%/yr
MOD:-1.2%/yr

12. Sum NH3+NH4+ (Sen slope: mgN/l per year), 1990-2012

13. NOx, NO2, NO3, NO3 precipitation, HNO3+NO3
NO2 around -30% in 20 years – good agreement between model and obs
Discussion of NOx emission reductions, NO2?
Ox. N conc in precip: tendency for larger trend in model
NO3+HNO3 in air: few sites have trends (more in model)
Difficult to see any trends for 10 years period

14. NO2 (Sen slope: ugN/m3 per year), 1990-2012
OBS:-1.2%/yr
MOD:-1.4%/yr

15. NO3+HNO3 (Sen slope: ugN/m3 per year)

16. Ox. N in precip (Sen slope: mgN/l per year), 1990-2012
OBS:-1.3%/yr
MOD:-2.2%/yr
Obs lower than
Model in early 90’s for e.g. DE,PL,FR
DE 1990: 10% lower in EMEP
PL 1990: 20% lower in EMEP

17. BC/EC/TC/OC Which reliable data really exists ?
Thermal optical protocol changed .. Probably EC does not work besides possibly some stations in Spain (incl. OC/TC). Maybe one could use TC alone for more sites.
Equivalent BC data should exist for several stations. Probably there is not enough data on EBAS
We should contact other groups working on EC/BC/TC trends

18. Trends of source categories
Examples of Barcelona, Montseny or other places in Spain are the only existing (Could be shown as examples)

19. MSC-East Prog applied to PMF source contributions in PM2
MSC-East Prog applied to PMF source contributions in PM2.5 (Montseny; RB)
Ammonium Sulfate
Cichord
NL = 11.48
4 harmonics Di
One Exp
F ̴ 0;
p-value =1
a1 = 5.56; t1 = 10.80; a11,1 = ; b11,1 = ; a11,2 = -0.37; b11,2 = 0.69 ;
a11,3 = -0.60; b11,3 = -0.06; ; a11,4 = 0.36; b11,4 = 0.49
a1 = 6.02 mgm-3; t1 = yr
Industrial
NL = 15.03
2 harmonics
One Exp
F ̴ 0
P-value = 0.3
a1 = 1.72 mgm-3; t1 = 8.68 yr
a1 = 1.71; t1 = 8.30; a11,1 = ; b11,1 = 0.040; a11,2 = ; b11,2 =

20. SUMMARY
PM10 / PM2.5 EMEP EBAS analyses need to be harmonized. Stations that can be used need to be chosen. Trend analysis of EMEP stations should be done the same way as the AirBase data in my opinion.
Sulfate/SO2 story rather clear
Reduced nitrogen rather clear
Oxidized nitrogen (relatively unclear, discrepancies between measurements and models) NOx, NO2 decreases probably rather clear, then it gets more difficult..
BC/EC/TC data really unclear.. One needs to figure out what is possible.
Examples of trends of source apportionment components could be given for Spain, probably only for Spain
How should one present the results in general?
Precipitation, precursor trends separately or together or partially together.
Focus on relative changes (100% needs definition) although absolute values are also important if one relates the absolute levels to exceedances/WHO recommendations,
Any discussions on meteorology adjusted trends?
...
A general concern: stations can be different when discussing the subperiods and Analyses of all stations should be accompanied by analyses of only the common stations of both periods