1. EC/OC – monitoring within EMEP
TFMM-Workshop
Helsinki May 2006
Karl Espen Yttri
Department for Atmospheric and Climate Research,
Norwegian Institute for Air Research (NILU) - CCC

2. Part one: Part two: Outline Current status Main findings so far
Tentative recommendations

3. EMEPs EC/OC Monitoring Strategy
- Level 2 and level 3 activity
The EMEP monitoring strategy Background document with
justification and specification of the EMEP monitoring programme, Ed. by Kjetil Tørseth and Øystein Hov. EMEP/CCC-Report 9/2003

4. Reporting - Current status
- Who reports?

5. Reporting - Current status
- Sampling equipment and analytical approach

6. EMEP EC/OC campaign - Main findings - Spatial distribution of TC/OC/EC
Lower
Figure 1:
Spatial distribution of the sampling sites participating in the EMEP EC/OC campaign and their annual mean concentration of EC, OC and TC for the period
1 July 2002 – 1 July 2003.
Higher

7. EMEP EC/OC campaign - Main findings
- Relative contribution of EM, OM and (EM + OM) to PM10

8. EMEP EC/OC campaign - Main findings
- Seasonal variation of OC in Scandiavia and Slovakia
Mean concentration of OC is 1.3 – 1.5 times higher in summer compared to winter at the Scandinavian sites and at the Slovakian site

9. EMEP EC/OC campaign - Main findings
- Wildfires with regional impact - I
Aspvreten (SE)
Birkenes (NO)
Stara Lesna (SK)
Virolahti (FI)

10. EMEP EC/OC campaign - Main findings
- Wildfires with regional impact - III
Aspvreten (SE)
Birkenes (NO)
Levoglucosan = 34 ng m-3
Levoglucosan = 84 ng m-3
Stara Lesna (SK)
Virolahti (FI)
Levoglucosan = 108 ng m-3
Levoglucosan = 110 ng m-3

11. FLEXPART (Stohl, A. et al., 2005. Atm. Chem. & Phys 5, 2461-2474)
Experiences on regional scale
- Wildfires with regional impact - IV
Aspvreten (Se) Aug. 2002
Stara Lesna (Sk) Aug. 2002
Birkenes (No) Aug. 2002
Virolahti (Fi) Aug. 2002
FLEXPART (Stohl, A. et al., Atm. Chem. & Phys 5, )

12. EMEP EC/OC campaign - Main findings
- Seasonal variation of OC in Scandiavia
Mean concentration of OC is 1.3 times higher in summer compared to winter at the Scandinavian sites

13. Additional analyses
- Annual variation of OC at Birkenes (NO)
2002
2003
2004
2005

14. - Seasonal variation of OC at Birkenes (NO) 2002 - 2005
Additional analyses
- Seasonal variation of OC at Birkenes (NO)
OC in PM10
Highest concentrations in early spring and late summer
Lowest concentrations in winter
OC in PM2.5 and PM10-2.5
PM2.5:
Highest concentrations in early spring
Lowest concentraions in winter
PM10-2.5:
Low concentrations in winter
High concentraions in summer

15. Prim. Biol. Aero. Part. (PBAP) Examples
Additional analyses
- Seasonal variation of sugars and sugar alcohols at Birkenes
Prim. Biol. Aero. Part. (PBAP) Examples
Virus
Pollen
Bacteria
The seasonal variation of sugars and sugar-alcohols resembles that of OCPM to - OCPM10
Spores

16. Levels of OCPM10-2.5 have been increasing from 2002 - 2005
Additional analyses
- Seasonal variation of OCPM at Birkenes
Levels of OCPM have been increasing from

17. - Seasonal variation of OCPM10-2.5 at Birkenes
Additional analyses
- Seasonal variation of OCPM at Birkenes
The relative contribution of OCPM to - OCPM have been increasing from 15 % in 2002 to 33 % in 2005

18. - Rationale - Analytical approach
Recommendations
- Rationale - Analytical approach
Only methods that correct for charring during analysis (TOT/TOR-methods) should be recommended for quantification of EC and OC (Schmid et al., 2001)
IMPROVE or NIOSH?
IMPROVE:
T < 550C in the oxygen free atmosphere (prevents unwanted oxidation of EC)
Signal goes back to baseline before the next temperature step is initiated (prevents charring)

19. - Rationale - Analytical approach
NIOSH:
IC comes as a part of the OC fraction, and not of the EC fraction (IMPROVE)  Less interference when the contribution of CaCO3 is substantial
The Sunset instrument (NIOSH) has been commercial available for quite a while, and has a record of being both robust an easy to operate. The DRI 2001 model (IMPROVE) was only recently available

20. - Rationale - Analytical approach
There are many more Sunset instruments around, both in Europe and world wide, compared to instruments from DRI
Thermal/Optical Carbon Analyzer (Desert Research Institute)
Carbon Aerosol Analysis Lab Instrument (Sunset lab)
Most commercial available EC/OC monitors operate according to the NIOSH protocol
Carbon Aerosol Analysis Field Instrument (Sunset lab)

21. Analytical approaches
- Benefit of in situ measurements
Monitors can provide sub-daily or hourly variability of EC and OC, which can improve current knowledge about:
Variability of sources
Ambient levels
Human exposure
In addition, monitors can be more economical to operate due to reduced sampling site visits and eliminated need of laboratory facilities and analysis costs
Time series for hourly fine particle concentrations of OC at St. Louis Midwest Supersites, September 2002

22. Analytical approaches
- Semicontinuous compared to off-line - TC
Little difference between 12 and 20 hours of sampling; implying that operating one sampler over a period of 12 hours, sampling every other hour is satisfactory

23. Analytical approaches
- Semicontinuous compared to off-line – EC and OC OC EC
Correlation less good for EC and OC than for TC
No data shown for only 12 hours of sampling!

24. Sampling approaches - Various approaches
Few studies concerning artifacts in Europe (urban areas/positive artefact)
Easier to assess the positive artefact
Alternatives: Tandem filter set up and denuder
QBQ: Straight forward and simple
QBT: Requires two samplers and three filters to obtain particulate OC
Recommendation positive artefact: QBQ
Recommendation negative artefact: non
Mader et al., Atm. Env. 37,

25. Analytical approaches
- The IMPROVE network
In the IMPROVE (Interagency Monitoring of Protected Visual Environments) network one type of sampler and one analytical approach is used at all sites!
Figure 1: Location of IMPROVE monitoring sites as well as the grouping of the sites
Figure 2: Schematic drawing of the new version of the IMPROVE sampler
Malm et al., 2004 JGR, doi: /2003JD003739, 2004