Infrequent new particle formation over the remote boreal forest of Siberia

A Wiedensohler,N Ma,W Birmili,J Heintzenberg,F Ditas,M.O Andreae,A Panov

doi:10.1016/j.atmosenv.2018.12.013

Abstract

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.

Highlights

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
The authors propose that the ELVOCs formed from monoterpene oxidation will help to explain the appearance and the subsequent rapid growth of new particles observed in forested regions
Hyytiälä might not be a fully representative observational site to prove new particle formation induced by ELVOCs alone, since it might be still influenced by gaseous sulfuric acid from anthropogenic SO2

Summary

Introduction

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. This work was a milestone for a better understanding of atmospheric oxidation processes of VOC as aerosol particle precursors, especially over boreal forest regions with negligible anthropogenic influence. The authors propose that the ELVOCs formed from monoterpene oxidation will help to explain the appearance and the subsequent rapid growth of new particles observed in forested regions.

Results

Conclusion