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)

Time 1990-2012 / 1990-2001 / 2002-2012 Percent change : 100%: median, beginning An option would be to set the trend line to 100% at 2001/1996/2007 Advantage: if e.g. 1990-1994 is missing .. The reference year would be the same as for a complete dataset

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

2. Trend analysis: PM10 (bkgd) Key results 2002-2012: Decrease throughout Europe Downward trend more pronounced in summer. 4

2. Trend analysis: PM10 (whole set) Key results 2002-2012: Decrease throughout Europe Downward trend more pronounced in summer 5

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

SO4 SO4 (Sen slope: ugS/m3 per year), 1990-2012 OBS MOD -2.6 -3.2 -4.4 1990-2012(%yr-1) -2.6 -3.2 1990-2001(%yr-1) -4.4 -4.8 2002-1012(%yr-1) -4.3 Model slightly larger trend

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

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

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

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

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

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

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

NO3+HNO3 (Sen slope: ugN/m3 per year) 1990-2012 2002-2012

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

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

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

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 = -2.86 ; b11,1 = -1.02 ; 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 = 10.05 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 = -0.088 ; b11,1 = 0.040; a11,2 = -0.253; b11,2 = -0.391

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 1990-2001 and 2002-2012. Analyses of all stations should be accompanied by analyses of only the common stations of both periods