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Type: Text × Subject: boreal forest × Subject: size distribution ×

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    Infrequent new particle formation over the remote boreal forest of Siberia
    (Amsterdam [u.a.] : Elsevier Science, 2018) Wiedensohler, A.; Ma, N.; Birmili, W.; Heintzenberg, J.; Ditas, F.; Andreae, M.O.; Panov, A.
    Aerosol particle number size distributions (PNSD) were investigated to verify, if extremely low-volatility organic vapors (ELVOC) from natural sources alone could induce new particle formation and growth events over the remote boreal forest region of Siberia, hundreds of kilometers away from significant anthropogenic sources. We re-evaluated observations determined at a height of 300 m of the remote observatory ZOTTO (Zotino Tall Tower Observatory, http://www.zottoproject.org). We found that new particle formation events occurred only on 11 days in a 3-year period, suggesting that homogeneous nucleation with a subsequent condensational growth could not be the major process, maintaining the particle number concentration in the planetary boundary layer of the remote boreal forest area of Siberia. © 2018 Elsevier Ltd
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    The atmospheric aerosol over Siberia, as seen from the 300 m ZOTTO tower
    (Milton Park : Taylor & Francis, 2017) Heintzenberg, Jost; Birmili, Wolfram; Theiss, Detlef; Kisilyakhov, Yegor
    This report describes a unique setup for aerosol measurements at the new long-term Tall Tower monitoring facility near Zotino, Siberia (ZOTTO). Through two inlets at 50 and 300 m aerosol particle number size distributions are measured since September 2006 in the size range 15–835 nanometer dry diameter. Until the end of May 2007 total number (N300) concentrations at 300 m height ranged between 400 cm-3 (5%) and 4000 cm-3 (95%) with a median of 1200 cm-3, which is rather high for a nearly uninhabited boreal forest region during the low productivity period of the year. Fitting 1-h average distributions with a maximum of four lognormal functions yielded frequent ultrafine modes below 20 nm at 50 m height than at 300 m, whereas the latter height more frequently showed an aged nucleation mode near 30 nm. The positions of Aitken (≈80 nm) and accumulation modes (≈210 nm) were very similar at both inlet heights, the very sharp latter one being the most frequent of all modes. The encouraging first results let us expect exciting newfindings during the summer period with frequent forest fires and secondary particle sources from vegetation emissions.