Ground-based PTR-MS measurements of reactive organic compounds during the MINOS campaign in Crete, July–August 2001

Abstract

Abstract. This study presents measurements of acetonitrile, benzene, toluene, methanol and acetone made using the proton-transfer-reaction mass spectrometry (PTR-MS) technique at the Finokalia ground station in Crete during the Mediterranean INtensive Oxidant Study (MINOS) in JulyAugust 2001. Three periods during the campaign with broadly consistent back trajectories are examined in detail. In the first, air was advected from Eastern Europe without significant biomass burning influence (mean acetonitrile mixing ratio 154 pmol/mol). In the second period, the sampled air masses originated in Western Europe, and were advected approximately east-south-east, before turning southwest over the Black Sea and north-western Turkey. The third well-defined period included air masses advected from Eastern Europe passing east and south of/over the Sea of Azov, and showed significant influence by biomass burning (mean acetonitrile mixing ratio 436 pmol/mol), confirmed by satellite pictures. The mean toluene:benzene ratios observed in the three campaign periods described were 0.35, 0.37 and 0.22, respectively; the use of this quantity to determine air mass age is discussed. Methanol and acetone were generally well-correlated both with each other and with carbon monoxide throughout the campaign. Comparison of the acetone and methanol measurements with the MATCH-MPIC model showed that the model underestimated both species by a factor of 4, on average. The correlations between acetone, methanol and CO implied that the relatively high levels of methanol observed during MINOS were largely due to direct biogenic emissions, and also that biogenic sources of acetone were highly significant during MINOS (∼35%). This in turn suggests that the model deficit in both species may be due, at least in part, to missing biogenic emissions.

Climatological aspects of aerosol optical properties in Northern Greece

“…Observations of enhanced SO 2 over Southeastern Europe by GOME (Eisinger and Burrows, 1998) as well as the fact that during NE directions about 70% of the SO 2 column can be attributed to lignite combustion in power plants in Bulgaria and Romania (Zerefos et al, 2000), can help to explain the maxima in aerosol loadings from the easterly sector. Biomass burning from areas at the northern coast of the Black Sea (Salisbury et al, 2003;Balis et al, 2003b) may also contribute episodically. Cleaner conditions, associated with fine aerosol particles, are found for the NW direction, in spite of the presence of the most industrialized countries of Central Europe being in this sector.…”

“…This can be attributed to the fact that sources of pollution with different seasonal characteristics (central heating, transportation, industrial activities etc.) are superimposed on the seasonality related to the change of (Salisbury et al, 2003;Balis et al, 2003b).…”

Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002

“…Good alternatives, however, are not readily available. Some authors have suggested the use of methanol as a biogenic tracer [Salisbury et al, 2003], but this work will show that primary anthropogenic sources of this VOC are also significant.…”

Importance of mineral cations and organics in gas-aerosol partitioning of reactive nitrogen compounds: case study based on MINOS results

“…The MINOS (Mediterranean INtensive Oxidant Study) campaign (Lelieveld et al, 2002;Salisbury et al, 2003) took place in summer 2001 (28 July till 21 August) with the objective to study the chemical and transport processes that cause the relatively high pollution concentrations often encountered in the Eastern Mediterranean lower atmosphere (Fig. 1).…”