South African EUCAARI – measurements : a site with high atmospheric variability

Non peer reviewe

Differences in aerosol absorption Ångström exponents between correction algorithms for particle soot absorption photometer measured on South African Highveld

Peer reviewe

Overview: Recent advances in the understanding of the northern Eurasian environments and of the urban air quality in China – a Pan-Eurasian Experiment (PEEX) programme perspective

The Pan-Eurasian Experiment (PEEX) Science Plan, released in 2015, addressed a need for a holistic system understanding and outlined the most urgent research needs for the rapidly changing Arctic-boreal region. Air quality in China, together with the long-range transport of atmospheric pollutants, was also indicated as one of the most crucial topics of the research agenda. These two geographical regions, the northern Eurasian Arctic-boreal region and China, especially the megacities in China, were identified as a "PEEX region". It is also important to recognize that the PEEX geographical region is an area where science-based policy actions would have significant impacts on the global climate. This paper summarizes results obtained during the last 5 years in the northern Eurasian region, together with recent observations of the air quality in the urban environments in China, in the context of the PEEX programme. The main regions of interest are the Russian Arctic, northern Eurasian boreal forests (Siberia) and peatlands, and the megacities in China. We frame our analysis against research themes introduced in the PEEX Science Plan in 2015. We summarize recent progress towards an enhanced holistic understanding of the land-atmosphere-ocean systems feedbacks. We conclude that although the scientific knowledge in these regions has increased, the new results are in many cases insufficient, and there are still gaps in our understanding of large-scale climate-Earth surface interactions and feedbacks. This arises from limitations in research infrastructures, especially the lack of coordinated, continuous and comprehensive in situ observations of the study region as well as integrative data analyses, hindering a comprehensive system analysis. The fast-changing environment and ecosystem changes driven by climate change, socio-economic activities like the China Silk Road Initiative, and the global trends like urbanization further complicate such analyses. We recognize new topics with an increasing importance in the near future, especially "the enhancing biological sequestration capacity of greenhouse gases into forests and soils to mitigate climate change" and the "socio-economic development to tackle air quality issues".Peer reviewe

A Simple Non-Linear Analytical Relationship between Aerosol Accumulation Number and Sub-Micron Aerosol Volume, Explaining their Observed Ratio in the Clean and Polluted Marine Boundary Layer.

Abstract not availableJRC.(EI)-Environment Institut

Processes Determining the Relationship between Aerosol Number and Non-Sea-Salt Sulfate Mass Concentrations in the Clean and Perturbed Marine Boundary Layer.

Abstract not availableJRC.(EI)-Environment Institut

cis-Pinic Acid, a Possible Precursor for Organic Aerosol Formation from the Ozonolysis of Alpha-Pinene.

A method for the analysis of carboxylic acids in aerosols was developed,based on the collection of particles on Teflon filters,extraction with dichloromethane, and derivatation with BF3-methanol followed by analysis of the formed methylesters by large volume injection GM/MS.In aerosol samples from smog chamber experiments with alpha pinene and ozone this method was applied and resulted in the identification for the first time of cis-pinic acid.Being a dicarboxylic acid this product is estimated to posess an extremely low vapour pressure and may thus be an important element in gas-to-particle conversion of alpha pinene.JRC.(EI)-Environment Institut

Validation of Very High Cloud Droplet Number Concentrations in Air Masses Transported Thousands of Kilometers over the Ocean.

Abstract not availableJRC.(EI)-Environment Institut