Significance of the organic aerosol driven climate feedback in the boreal area

Taina Yli-Juuti; Tero Mielonen; Liine Heikkinen; Antti Arola; Mikael Ehn; Sini Isokääntä; Helmi-Marja Keskinen; Markku Kulmala; Anton Laakso; Antti Lipponen; Krista Luoma; Santtu Mikkonen; Tuomo Nieminen; Pauli Paasonen; Tuukka Petäjä; Sami Romakkaniemi; Juha Tonttila; Harri Kokkola; Annele Virtanen

doi:10.1038/s41467-021-25850-7

Significance of the organic aerosol driven climate feedback in the boreal area

Nat Commun. 2021 Sep 24;12(1):5637. doi: 10.1038/s41467-021-25850-7.

Authors

Taina Yli-Juuti¹, Tero Mielonen², Liine Heikkinen³, Antti Arola², Mikael Ehn³, Sini Isokääntä⁴, Helmi-Marja Keskinen^{3

5}, Markku Kulmala³, Anton Laakso², Antti Lipponen², Krista Luoma³, Santtu Mikkonen^{4

6}, Tuomo Nieminen^{4

3

7}, Pauli Paasonen³, Tuukka Petäjä³, Sami Romakkaniemi², Juha Tonttila², Harri Kokkola², Annele Virtanen⁴

Affiliations

¹ Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. taina.yli-juuti@uef.fi.
² Atmospheric Research Centre of Eastern Finland, Finnish Meteorological Institute, Kuopio, Finland.
³ Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Helsinki, Finland.
⁴ Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
⁵ Aerosol Physics Laboratory, Physics Unit, Tampere University, Tampere, Finland.
⁶ Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland.
⁷ Institute for Atmospheric and Earth System Research/Forest Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Helsinki, Finland.

Abstract

Aerosol particles cool the climate by scattering solar radiation and by acting as cloud condensation nuclei. Higher temperatures resulting from increased greenhouse gas levels have been suggested to lead to increased biogenic secondary organic aerosol and cloud condensation nuclei concentrations creating a negative climate feedback mechanism. Here, we present direct observations on this feedback mechanism utilizing collocated long term aerosol chemical composition measurements and remote sensing observations on aerosol and cloud properties. Summer time organic aerosol loadings showed a clear increase with temperature, with simultaneous increase in cloud condensation nuclei concentration in a boreal forest environment. Remote sensing observations revealed a change in cloud properties with an increase in cloud reflectivity in concert with increasing organic aerosol loadings in the area. The results provide direct observational evidence on the significance of this negative climate feedback mechanism.

Publication types

Research Support, U.S. Gov't, Non-P.H.S.
Research Support, Non-U.S. Gov't