Abstract
Abstract. Chemically resolved (organic, nitrate, sulfate, ammonium) data of non-refractory submicron (NR-PM1) aerosol from the first long-term deployment (27 July 2012 to 02 October 2013) of a time-of-flight aerosol chemical speciation monitor (ToF-ACSM) at the Swiss high-altitude site Jungfraujoch (JFJ; 3580 m a.s.l.) are presented. Besides total mass loadings, diurnal variations and relative species contributions during the different meteorological seasons, geographical origin and sources of organic aerosol (OA) are discussed. Backward transport simulations show that the highest (especially sulfate) concentrations of NR-PM1 were measured in air masses advected to the station from regions south of the JFJ, while lowest concentrations were seen from western regions. OA source apportionment for each season was performed using the Source Finder (SoFi) interface for the multilinear engine (ME-2). OA was dominated in all seasons by oxygenated OA (OOA, 71–88 %), with lesser contributions from local tourism-related activities (7–12 %) and hydrocarbon-like OA related to regional vertical transport (3–9 %). In summer the OOA can be separated into a background low-volatility OA (LV-OOA I, possibly associated with long-range transport) and a slightly less oxidised low-volatility OA (LV-OOA II) associated with regional vertical transport. Wood burning-related OA associated with regional transport was detected during the whole winter 2012/2013 and during rare events in summer 2013, in the latter case attributed to small-scale transport for the surrounding valleys. Additionally, the data were divided into periods with free tropospheric (FT) conditions and periods with planetary boundary layer (PBL) influence, enabling the assessment of the composition for each. Most nitrate and part of the OA are injected from the regional PBL, while sulfate is mainly produced in the FT. The south/north gradient of sulfate is also pronounced in FT air masses (sulfate mass fraction from the south: 45 %; from the north: 29 %). Furthermore, a detailed investigation of specific marker fragments of the OA spectra (f43, f44, f55, f57, f60) showed different degrees of ageing depending on season.
Highlights
IntroductionMany environmental topics which are becoming increasingly important in the future are closely linked to aerosols, e.g. climate change on global (Charlson et al, 1992; Lohmann and Feichter, 2005; Boucher et al, 2013) and regional scales (Ramanathan et al, 2001; Stott, 2003; Shindell and Faluvegi, 2009), or impacts on human health (Seaton et al, 1995; Laden et al, 2000; Cohen et al, 2005; Pope and Dockery, 2006) and Earth’s ecosystem (Mahowald, 2011)
While total PM1 concentrations in the night and morning usually were below 1 μg m−3, they increased to several μg m−3 in the evening hours
A likely reason is a thunderstorm causing large-scale turbulences, i.e. vertical mixing of air masses which were subsequently transported to the JFJ site
Summary
Many environmental topics which are becoming increasingly important in the future are closely linked to aerosols, e.g. climate change on global (Charlson et al, 1992; Lohmann and Feichter, 2005; Boucher et al, 2013) and regional scales (Ramanathan et al, 2001; Stott, 2003; Shindell and Faluvegi, 2009), or impacts on human health (Seaton et al, 1995; Laden et al, 2000; Cohen et al, 2005; Pope and Dockery, 2006) and Earth’s ecosystem (Mahowald, 2011). A good knowledge of aerosol chemical and physical properties in the atmosphere is an essential scientific task. Knowledge of the aerosol concentrations and properties in the lower FT is important due to its impact on cloud formation and to validate model results from the FT. The high-altitude research station on the Jungfraujoch (JFJ) at 3580 m a.s.l. in the Swiss Alps allows the investigation of free tropospheric aerosol year round due to its elevated location. Due to its well-developed infrastructure and unique location many decades of scientific measurements of gas-phase constituents (Zander et al, 2008; Pandey Deolal et al, 2012), meteorology (Appenzeller et al, 2008) and atmospheric aerosols (Baltensperger et al, 1997; Collaud Coen et al, 2007; Cozic et al, 2008; Bukowiecki et al, 2015) have been performed there. Given the absence of local vegetation and small scale of local emissions, the JFJ is an ideal location for the measurement of pollution arriving from all over Europe (Reimann et al, 2008; Uglietti et al, 2011)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
