Insights into the sources of ultrafine particle numbers at six European urban sites obtained by investigating COVID-19 lockdowns
Alex Rowell,James Brean,David C. S. Beddows,Tuukka Petäjä,Máté Vörösmarty,Imre Salma,Jarkko V. Niemi,Hanna E. Manninen,Dominik van Pinxteren,Thomas Tuch,Kay Weinhold,Zongbo Shi,and Roy M. Harrison
Alex Rowell
School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
James Brean
School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
David C. S. Beddows
School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, United Kingdom
Different sources of airborne particles in the atmospheres of four European cities were distinguished by recognising their particle size distributions using a statistical procedure, positive matrix factorisation. The various sources responded differently to the changes in emissions associated with COVID-19 lockdowns, and the reasons are investigated. While traffic emissions generally decreased, particles formed from reactions of atmospheric gases decreased in some cities but increased in others.
Different sources of airborne particles in the atmospheres of four European cities were...
