Chemical characteristics assigned to trajectory clusters during the MINOS campaign

Abstract

Abstract. During the Mediterranean Intensive OxidantStudy (MINOS) in August 2001 a total of 14 measurement flights were performed with the DLR Falcon jet aircraft from Heraklion, Crete. One objective of this campaign was to investigate the role of long-range transport of pollutants into the Mediterranean area. An analysis of 5-day back trajectories indicates that in the lower troposphere (0-4 km) air masses originated from eastern and western Europe, in the mid-troposphere (4-8 km) from the North Atlantic Ocean region and in the upper troposphere (8-14 km) from North Atlantic Ocean/North America (NANA) as well as South Asia. We allocated all back trajectories to clusters based on their ending height and source region. The mixing ratios of ozone, nitrogen oxide, total reactive oxidized nitrogen (NO y ), formaldehyde, methanol, acetonitrile, acetone, peroxyacetyl nitrate (PAN), carbon dioxide, carbon monoxide and methane measured along the flight tracks are examined in relation to the different cluster trajectories. In the lower troposphere the mean trace gas mixing ratios of the eastern Europe cluster trajectories were significantly higher than those from western Europe. In the upper troposphere air from the NANA region seems to be influenced by the stratosphere, in addition, air masses were transported from South Asia, being influenced by strong convection in the Indian monsoon.

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

“…Most pollution was observed in the lower 4 km, originating from both western and eastern Europe (Lelieveld et al, 2002;Traub et al, 2003). During MINOS the observations at Finokalia were strongly influenced by the transport of air pollution from SE-Europe.…”

Oxygenated compounds in aged biomass burning plumes over the Eastern Mediterranean: evidence for strong secondary production of methanol and acetone

“…At the lowest two altitude levels significantly lower average than median mixing ratios were observed. From trajectory analysis (Traub et al, 2003) we can exclude that these air masses had been recently mixed with clean background air, so we conclude that the variability in the lowest 4 km of the troposphere was higher due to a stronger influence from biomass burning sources and uptake into the sea. Interestingly, the variability was also higher at altitudes above 11 km.…”

“…those below 2km and east of 24 • E) are likely to originate from agricultural burning, a great deal of which was occurring in Eastern Europe at the time of the MINOS campaign. According to a trajectory analysis the age of these plumes was about 2-3 days (Traub et al, 2003). It was not possible to identify the source region of the other plumes.…”

“…This is also supported by results from a ship cruise across the tropical Atlantic; most time water concentrations of acetonitrile were found to be in equilibrium with air concentrations . Based on the trajectory analysis by Traub et al (2003) we split the dataset into 4 sub-sets (North Atlantic, Western Europe, Eastern Europe, and South Asia) according to the source region of the air masses; typical acetonitrile mixing Traub et al (2003).…”

Aerosol distribution over the western Mediterranean basin during a Tramontane/Mistral event

“…The aerosols found below 4-km height originate from regional sources, especially from western and eastern Europe (e.g. Sciare et al, 2003;Traub et al, 2003;Schneider et al, 2004), and from the Saharan desert (e.g. Bergametti et al, 1992;Moulin et al, 1998;Guieu et al, 2002).…”