EC/OC – monitoring within EMEP TFMM-Workshop Helsinki 10-12 May 2006 Karl Espen Yttri Department for Atmospheric and Climate Research, Norwegian Institute for Air Research (NILU) - CCC

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

EMEPs EC/OC Monitoring Strategy - Level 2 and level 3 activity The EMEP monitoring strategy 2004-2009. Background document with justification and specification of the EMEP monitoring programme, 2004-2009 Ed. by Kjetil Tørseth and Øystein Hov. EMEP/CCC-Report 9/2003

Reporting - Current status - Who reports?

Reporting - Current status - Sampling equipment and analytical approach

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

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

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

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

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

FLEXPART (Stohl, A. et al., 2005. Atm. Chem. & Phys 5, 2461-2474) Experiences on regional scale - Wildfires with regional impact - IV Aspvreten (Se) 20-21 Aug. 2002 Stara Lesna (Sk) 20-21 Aug. 2002 Birkenes (No) 27-28 Aug. 2002 Virolahti (Fi) 28-29 Aug. 2002 FLEXPART (Stohl, A. et al., 2005. Atm. Chem. & Phys 5, 2461-2474)

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

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

- Seasonal variation of OC at Birkenes (NO) 2002 - 2005 Additional analyses - Seasonal variation of OC at Birkenes (NO) 2002 - 2005 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

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 OCPM10-2.5 - to - OCPM10 Spores

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

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

- 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)

- 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

- 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) http://www.dri.edu/ http://www.Sunlab.com/ Most commercial available EC/OC monitors operate according to the NIOSH protocol Carbon Aerosol Analysis Field Instrument (Sunset lab) http://www.Sunlab.com/

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

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

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!

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., 2004. Atm. Env. 37, 1435 - 1449

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:10.1029/2003JD003739, 2004