Strong particle production and condensational growth in the upper troposphere sustained by biogenic VOCs from the canopy of the Amazon Basin

• DOI: 10.5194/acp-23-251-2023
• Publication Date: 2023-01-13T07:02:04Z
• Authors: Yunfan Liu; Hang Su; Siwen Wang; Chao Wei; Wei Tao; Mira L. Pöhlker; Christopher Pöhlker; Bruna A. Holanda; Ovid O. Krüger; Thorsten Hoffmann; Manfred Wendisch; Paulo Artaxo; Ulrich Pöschl; Meinrat O. Andreae; Yafang Cheng
• Keywords: Cloud condensation nuclei; Supersaturation; Particle (ecology)

Abstract. Nucleation and condensation associated with biogenic volatile organic compounds (BVOCs) are important aerosol formation pathways, yet their contribution to the upper-tropospheric aerosols remains inconclusive, hindering understanding of climate effects. Here, we develop new schemes describing these processes in WRF-Chem model investigate impact on abundance cloud nuclei (CCN) upper troposphere (UT) over Amazon Basin. We find that significantly increase simulated CCN number concentrations UT (e.g., up ∼ 400 cm−3 at 0.52 % supersaturation) greatly improve agreement aircraft observations. Organic enhances concentration by 90 through promoting particle growth, while nucleation, replenishing particles, contributes an additional 14 %. Deep convection determines rate controlling upward transport precursors (i.e., BVOCs). This finding emphasizes importance biosphere–atmosphere coupling regulating tropical forest calls for attention its potential role anthropogenic change.