Characteristics and sources of PM in seasonal perspective - a case study from one year continuously sampling in Beijing.

Daily mass concentrations and chemical compositions (elemental carbon, organic carbon, water soluble ions, chemical elements and organic species) of PM were measured continuously in Beijing for one year from June 2010 to June 2011 (365 samples). The seasonal variation of PM mass concentration followed the order of spring 2011 > winter 2010 > summer 2010 > autumn 2010. Organic matter (OM) and secondary inorganic aerosol components (SNA: SO42-, NO3- and NH4+) were the two major fractions of PM during the whole year. Source apportionment by PMF performed on the basis of a full year of data, including both inorganic and organic species, showed that biomass burning, secondary sulfate and nitrate formation, mineral dust, industry, coal combustion and traffic were the main sources of PM in Beijing during 2010-2011. Specifically, comparison among the four seasons shows that the contribution of secondary sulfate and biomass burning, secondary nitrate formation, mineral dust, and coal combustion were the dominating sources of PM in summer, autumn, spring and winter, respectively. The contributions of industry to PM was distributed evenly in four seasons, while traffic contributed more in summer and autumn than in winter and spring. Backward trajectory analysis was applied in combination with PMF and showed that air flow from the South contributed mostly to high PM mass concentrations in Beijing. Meteorological parameters (temperature, wind speed, wind direction, precipitation and mixing layer height) influence such a variation. In general, high relative humidity and low mixing layer height can raise PM mass concentration, while high wind speed and precipitation can reduce pollutants. In addition, wind direction also plays a key role in influencing PM because different wind directions can bring different pollutants to Beijing from different regions

Seasonal variation of airborne particles characteristics and sources in Beijing during 2010-2011

A lot of emission reduction measures to improve the air quality in Beijing were performed during the Olympic Summer Games in 2008, which has cut down coarse particles largely. But high air pollution has become more frequent (Du et al., 2014; Gao et al., 2014). In order to find out the long-term characteristics of airborne PM in different seasons, a continuous oneyear daily mean PM sampling from June 2010 till June 2011 was performed on the ground at the campus of the China University of Geosciences, Beijing (CUGB). To discriminate the composition of PM2.5 source attribution, particle characteristics and external impacts on the PM levels were investigated. Two sequential High-Volume operated to collect PM4 samples. The inorganic elements, inorganic water-soluble ions, EC and OC as well as Levoglucosan, eleven hopane substances and eleven PAHs of PM were analysed from PM samples by PEDXRF, ICP-MS, IC, thermal/optical carbon analyser and in situ derivatisation direct thermal desorption gas chromatography time-offlight mass spectrometry (IDTD-GC-TOFMS), respectively. Positive matrix factorization (version 3.0, U.S. EPA) on the basis of the chemical composition analyses and back trajectory cluster analyses were combined together to perform source apportionment. The results show that the main sources of particles during haze are different from season to season (Figure 1): secondary inorganic ions formation and biomass burning for summer and autumn haze, coal combustion for winter haze and mineral dust emissions for spring haze. Sources of PM during clear days were dominated by mineral dust emissions and traffic while haze was characterized by secondary inorganic ions formation during the whole year. High air pollution was found to be always accompanied by southerly air flows (industry and cities are about 100 km away), high relative humidity, low mixing layer height and low wind speed, i.e. stagnant weather conditions (Liu et al., 2014)

Discursively ‘Undoing’ and ‘Doing Europe’ the Austrian Way

Literature on European and national identities displays a tension between occasional observations of an emerging ‘banal Europeanism’ (Cram, 2009) and a dominant strand (e.g. Guibernau, 2007; Toplak & Šumi, 2012) that questions the viability of European identifications vis-à-vis historically entrenched nationalisms, particularly in the context of the debt crisis and the resulting (re)nationalization of European politics. This chapter builds on recent work on Austrian European Union (EU) scepticism and its contestation (Karner, 2013) to examine instances – in diverse media coverage, readers’ letters to the editor of Austria’s most widely read newspaper, internet platforms, political essays and party political positions – of national identity negotiations in relation to the EU and as articulated in the context of successive European crises and the most recent elections to the European Parliament. The qualitative, thematic analysis of these wide-ranging materials developed here draws on two key concepts in critical discourse analysis, the notions of deixis (Billig, 1995) or ‘rhetorical pointing’ and of the topos or ‘structure of argument’ (e.g. Reisigl & Wodak, 2001), which are complemented by a third theoretical tool, namely the anthropological concept of ‘grammars of identity’ (Baumann & Gingrich, 2004). The resulting discussion reveals the uneasy coexistence of (critical) Europeanisms and various national reassertions in Austria’s public sphere and their respective discursive features. Further, the theoretical approaches synthesized cast light on internal diversities within political positions that are often too monolithicly classified as being ‘simply’ pro- or anti-European respectively. Instead, the analysis presented here reveals a spectrum of (at least five) competing positions