Characterization of the inter-annual, seasonal, and diurnal variations of condensation particle concentrations at Neumayer, Antarctica

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Weller, Rolf, Minikin, Andreas, Wagenbach, Dietmar, Dreiling, Volker
• Format: Other Non-Article Part of Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2011
• Subjects: Atmosphärische Spurenstoffe; Southern Ocean; Austral; Neumayer; Neumayer Station; Soi; Antarc*; Antarctica
• Online Access: https://elib.dlr.de/73379/; https://elib.dlr.de/73379/1/weller-et-al_2011_acp-11-13243-2011_condensation-particles-neumayer.pdf; http://www.atmos-chem-phys.net/11/13243/2011/acp-11-13243-2011.html

Continuous condensation particle (CP) observations were conducted from 1984 through 2009 at Neumayer Station under stringent contamination control. During this period, the CP concentration (median 258 cmâ��3) showed no significant long term trend but exhibited a pronounced seasonality characterized by a stepwise increase starting in September and reaching its annual maximum of around 103 cmâ��3 in March. Minimum values below 102 cmâ��3 were observed during June/July. Dedicated time series analyses in the time and frequency domain revealed no significant correlations between inter-annual CP concentration variations and atmospheric circulation indices like Southern Annular Mode (SAM) or Southern Ocean Index (SOI). The impact of the Pinatubo volcanic eruption and strong El Ni�±o events did not affect CP concentrations. From thermodenuder experiments we deduced that the portion of volatile (at 125 �°C) and semi-volatile (at 250 �°C) particles which could be both associated with biogenic sulfur aerosol, was maximum during austral summer, while during winter non-volatile sea salt particles dominated. During September through April we could frequently observe enhanced concentrations of ultrafine particles within the nucleation mode (between 3 nm and 7 nm particle diameter), preferentially in the afternoon.